The following articles are taken from the MC aktiv publication and curated by Buidling Chemical Supplies Ltd. Content contained is therefore the property of MC-Bauchemie Müller GmbH & Co. KG.
The following articles are taken from the MC aktiv publication and curated by Buidling Chemical Supplies Ltd. Content contained is therefore the property of MC-Bauchemie Müller GmbH & Co. KG.
Until the opening up of the borders, the Czech Republic only had a limited network of motorways and highways. It then became clear that the existing infrastructure would not be able to cope with the expected increase in traffic.
At the beginning of the 90s, the Czech government recognized the necessity to create links to the motorway networks of its neighbouring countries and planned to extend the national network by 2010. The intention was to initiate both new construction and the completion of important links.
In 1994, the government decided to begin with the extension of the motorway D 5, the so-called "Via Carolina". It is the most important link between Prague, Pilsen and Rozvadov. A 61 km long project thus became the largest one in the Czech Republic. The invitation to tender was • issued internationally by the Road and Street Directory (RSD), requiring, for the first time in the Czech Republic, a quality management system according to DIN EN ISO 9000. Furthermore, the road surface was planned to be constructed of concrete as concrete is resistant to the high levels of stress and deformation. Due to the special technology used in the production of the concrete surface, the danger of skidding is minimized.
The project was awarded to the syndicate TMCR (Philipp Holzmann, Held & Franke a.s., Minchov and lmpregilo a.s.). It awarded the project management to Dalnicnf stavby Praha a.s., a sister company of the German building contractors Heilit & Woerner.
Thanks to its extensive range of products and services, MC was considered as a supplier of concrete admixtures from the beginning. For this project it was important to select, the right combination of concrete plasticizers and air-entraining agents, as a high resistance to de-icing salts was required. The first trials were carried out in a central laboratory in Munich and then implemented in the Czech Republic. Following these very extensive and demanding tests, the plasticizer Muraplast FK 19 and the air-entraining agent Centrament Air 202 were selected. The concrete curing agent used was Emcoril B VM.
Around 300,000 cubic metres of concrete for 1.2 million square metres was poured on the 61 km long section. Totally complying with the highly technical requirements, the D 5 was completed after 39 months of construction work and was opened in November 1997.
The company Dálničíf Stavby appreciated the result, particularly with regards to the selection of products and the excellent consultancy provided by MC. They subsequently opted for MC on further motorway projects. MC's quality and range of services also convinced the company DOSTA a.s. (now Qartof the Swedish building contractor SKANSKA AB). They are the second largest company in the Czech Republic and provide the technology for the production of concrete road surfaces. In partnership with MC they completed a number of projects during recent years.
Altogether, MC achieved extraordinary results in the Czech Republic: Since 1995 it participated in the construction or refurbishment of 190 km of motorway. This means that more than 90% of all Czech motorways contain MC concrete admixtures. In numbers this signifies 1,000 tons of plasticiser, 200 tons of air-entraining agents and 350 tons of treatment agents with a total turnover of more than one million Euros. An exceptional achievement, which would not have been possible without the commitment of the MC team of consultants and specialists in the Czech Republic.
Even before Poland's entry into the European Union it became evident that the capacity of the Frederic Chopin International Airport in Warsaw would not be enough to deal with the increasing air traffic. An extension was therefore inevitable.
On 12th November 2003, Warsaw Airport Authority, the construction syndicate Ferrovial Agroman AG and Budimex AG as well as the project consultants Estudio Lamela SL signed the contracts. A second terminal for an annual passenger capacity of three million together with the respective infrastructure such as car parks and transport connections was planned on an area of around 100,000 m2 Moreover, the existing facilities had to be modernised and comply with the latest standards. The costs for this large project were estimated to reach 200 million Euros. Completion is planned for 15th April 2006.
The project consultants, Lamela of Madrid, have high expectations of the participating companies. For a project this size, only suppliers with the necessary know-how and accreditations were considered.
MC has been present in Poland for over 10 years and in this time has become the leading specialist in the field of concrete admixtures. It is participating in a number of construction projects and has gained extensive experience in the management of large projects. MC Poland were successful during the selection process for this demanding project in convincing the clients because of the high technical standards of their products and its customer oriented range of services. Tadeusz Wasag, (Sales Manager - building protection) of the Polish organization has followed this project from the beginning and contributed considerably to its success.
For the huge volume of 300,000 m3 of concrete needed for the construction of the terminal, !be decking areas and the necessary infrastructure as well as further airport areas, the MC products Centrament P 40 and Muraplast FK 88 were used. So far, 50 tons of these products have been supplied to Bosta Beton and Dyckerhoff Ready Mix Concrete that are supplying the airport construction site as a team.
This well-known project in the capital Warsaw confirms once more the outstanding market position of MC in Poland.
With the construction of the innovative large capacity aircraft, the A 380, the Airbus syndicate has set a new milestone in its history. This new type of plane stands for a long term, strategic investment into the future of aeronautics. The high demand for the A 380, that is planned to be operated by a number of renowned airlines from 2006, shows that the company has taken the right course.
The construction of the Airbus A 380 requires its own assembly hall constructed at the dockyard in Hamburg-Finkenwerder, Germany. Thus in 2001 the "Miihlenberger Loch" project commenced with preparation for the construction of the first sections of the assembly hangar. This, in the first stage of extension will be approximately 230 m long, 120m wide and 26m high.
Here, the front and back body sections will be assembled and all the necessary flight systems installed.
A total of 2,100 concrete piles for the support of the A 380 hall were poured. A company, such as Airbus, that manufactures high-tech products has the same demands with regards to the quality of work of its suppliers and subcontractors. Consequently the 1st order from Airbus Germany was given to Becker Bau from Bornhöved.
The competency of MC-Bauchemie in the field of concrete admixtures and the long experience gained in other projects resulted in the participation of MC in the project. Hilmar Koppen was assigned as site manager for this project. During the pre-trials and tests MC convinced View of the new paint half the client and main contractor with their technical innovation and subsequently received the order for the supply of concrete admixtures for the piles, paving quality and structural concrete. In addition MC concrete coatings were supplied and applied.
From the beginning of the work in 2002 until today, MC has supplied products for more than a total of 300,000 m3 of concrete. Up to now, all the work has been successfully executed without problems or delays. This is largely due to, amongst other factors, the good relationship the MC building protection team has with the other participating companies.
The refurbishment of existing buildings is becoming an increasingly important business sector, thanks to positive growth rates in this market, and not just in Germany. The emphasis is more and more on maintaining structures and thus securing asset values. In order to develop this promising market internationally, MC created the brand Oxal.
The popular Dichtament range will be sold both nationally and internationally under this new brand. In addition to the product range for the refurbishment of facades, balconies as well as cellars and their internal and external areas, the available service Susanne Kasparek has been extended considerably. Susanne Kasparek is responsible for the target oriented package of effective products and services for redevelopment projects.
MC is the first manufacturer to receive approval from the German Institute for Construction Technology for its new stable and highly reactive silica fume suspension.
Centrilit Fume SX's particular characteristics are increased density and improved stability. The advantages for the client are the ease of application, its high efficiency and low dosage. Centrilit Fume SX can be added to all types of concrete, binder systems or concrete mix designs, e.g. as pump aid, concrete admixture, grout and injection mortar as well as an additive for screeds. It is planned that the new product will be produced and sold both on the local and foreign market.
Since May 2005 Munich has been the proud owner of an imposing new structure - the Allianz-Arena. Without doubt a stadium of superlatives and the latest attraction of the Bavarian capital.
Situated in Frottmaning, this stadium holds many structural and design feature records. It signifies a milestone in modern architecture and surely counts as one of the most beautiful stadiums in the world. Under cover seating for 66,000 fans and boasting Europe's largest multi-storey car park with spaces for 9,800 cars. The amount of concrete poured totalled 120,000 cubic metres for the stadium and a further 85,000 cubic metres for the multi-storey car park.
The ready-mix concrete was supplied by Marker Transport-beton GmbH, who set up two special mixing plants in Frottmaning for the duration of the project. The on-site concrete control was carried out by Munchner Baustoff-Prufungs GmbH, who manned the site concrete laboratory.
The pre-cast concrete units, 2,446 stand parts as well as the 3,985 stair blocks were supplied by Dipl.-lng. E. Honninger Fertigteilwerk, Eglharting, and Buchenrieder Fertigteilwerk, Landshut, respectively. The spun concrete elements, (concrete class C 60/75) came from the Swiss company Varinorm in Littau near Luzern.
Owing to excellent contacts and references MC secured orders for the high performance concrete admixtures. MC also supplied the various concrete repair materials as well as the hydrophobic treatment for the above ground structures and the water proofing for the public entrances across the esplanade.
The high temperatures during building works in the summer of 2003 proved problematic. These climactic conditions dictate the way the concrete is mixed, transported and placed. Concrete manufacturers and technologists know how difficult it is to achieve high concrete quality under high ambient temperatures. The concrete mix design and exact admixture dosage are critical. Three different strength classes of concrete were used and pre-cast concrete units were supplied by three other companies. Different grades and suppliers of concrete all had slight differences in colour and texture. It therefore fell on MC's department for application technology to create special colour samples of the proposed cosmetic repair products to match the various elements.
MC field manager Karl StrauB was the main contact and advisor to the construction supervision of Allianz-Arena, providing solutions to the various problems encountered along the way. Applications Engineer Uwe Strauch produced samples and advised on matters regarding application technology. Regional Sales Manager Lorenz Figge advised the concrete supplier Marker Transport beton. The primary admixtures that were used on this prestigious project were Centrament N 4 for the main structure of the stadium, Muraplast FK 48 for the multi-storey car park, plus several products from the Emcefix range.
The concrete construction phase lasted from November 2002 right through to shortly before its inauguration in May this year.
The opening match of the Football World Cup 2006 is going to introduce this 'Stadium of Superlatives' to the sport's fans of the world.
July 6th is not a day famed for outstanding events unless you count the release of the Beatie's film A Hard Days Night" in 1964 or the execution of Thomas More in 1535. However, 6th July 2005 is a significant milestone for the contractors and engineers involved in the construction of the Prai River Bridge as part of the Butterworth Ring Road Project in the northwest of Malaysia.
Butterworth is a town on mainland Malaysia, situated across the strait from the island of Penang, known in tourist brochures as the "Pearl of the Orient".
Over the past few years Butterworth and its neighbour across the water have developed their tourist, industrial and residential facilities. They are also meeting the necessary increase in demands on the infrastructure, especially road construction. As part of the overall scheme a 14 km expressway, forming the outer ring road, is being constructed by Malaysia's foremost construction company, IJM Construction Sdn Bhd. around the bustling town of Butterworth.
An important part of the project is the construction of the Prai River Bridge. The bridge is 1.85 km long and will carry a dual three lane highway with a dedicated trumpet interchange to the port.
It was on 6th July 2005 that the final section of the two pylons that will support the bridge deck were cast. It was also a significant day for MC-Bauchemie Malaysia, as they supplied the key admixtures that enabled the high performance concrete to meet the stringent and demanding specifications.
The engineering design of the structure specified that the concrete should achieve a minimum compressive strength of 80 N/mm2 in 28 days. When one considers that the vast majority of concrete produced today is only required to reach 30 N/mm2, and only a few years ago 50 N/mm2 was considered high strength, this achievement is brought into perspective.
Hanson (Malaysia) supplied the ready-mix concrete into which the admixtures were incorporated. Their technical staff worked closely with Eugen Kleen and Kathi Ravan of MC-Bauchemie Bottrop and MC-Bauchemie Malaysia respectively to develop the mix design. To meet the specification it was necessary to simultaneously use two very different admixtures. Water reduction and workability requirements were met by Muraplast FK 63, one of MC-Bauchemie's new generation of high performance polycarboxylate- based admixtures. The additional boost to the strength and durability was achieved adding Centrilit Fume SX, which is unique in being a stable slurry of a special silica fume. In addition to the strength requirements the durability potential was assessed with the Rapid Chloride Permeability (RCP) test. Months of trial mixes and the installation of the necessary dispensing equipment preceded the successful use of these two products and ultimately the success of the overall project.
The volume of concrete placed, 600 cubic metres, is a relatively small amount. The significance here lies in the technology of MC-Bauchemie materials, the expertise and dedication of MC's technical staff and the close cooperation between all parties involved that achieved the desired result.
In Hungary, just as in most other new EU member states, improvement of the traffic infrastructure is of great importance. Hence the relevant investment plans contain, amongst other things, the redevelopment and expansion of existing motorways and the development of new routes.
One of the great projects of the current year is the construction of the "M 0", the circular motorway around Budapest in the section between the towns of Gyal and Vecses. Because of the anticipated high volume of traffic the road surface was to be constructed with concrete once again – since 30 years.
This large-scale project was assigned to Strabag AG Hungary as main contractor. The concrete was partially supplied by Strabag AG Frissbeton Hungary and the execution of road surface works was done by Strabag AG, head office Hamburg. Strabag chose MC as supplier of concrete admixtures because its systems are renowned for their high technical standard and MC's extensive technological expertise ensures that the road surface can withstand high loads and can stand the test of time.
Right from the start of the project there was close collaboration between the two companies, for example in the development of the concrete mix design. One of the key factors was determining the air void spacing and distribution, which is decisive for the quality and durability of the concrete. A concrete road surface must be able to withstand heavy loads and must be resistant to frost and de-icing salts. In order to fulfil these criteria the highly effective plasticiser Muraplast FK 88 and the air-entraining agent Centrament Air 202 were used.
Not only did MC technicians assist with the selection and optimisation of the most suitable concrete admixtures, they also supported the handling of technical equipment for the on-site measurement of the air void spacing and distribution. Thanks to the good team work between MC and Strabag Frissbeton the motorway project "M 0" could be completed successfully. On this stretch of the motorway 107,000 m3 of concrete was used. A further 50,000 m3 was used for bridge construction. And additional motorway sections, requiring almost 500,000 m3 of concrete, are to be implemented by 2007.
In addition to Construction Chemicals the area of Protection Technologies also did well in Hungary by supplying surface waterproofing products. A total area of 15,000 m2 was sealed. Other notable projects were the preservation and restoration of listed buildings and the repair of underground stations and tunnels of the Metro M 2. Many bridges of the Hungarian Railways (MAV) were repaired and made waterproof by injection methods.
For Hungary, increased investment in the redevelopment and expansion of transport routes is expected for the coming year, as the European Union intends to make additional funding available.
This year the city of Dresden will be celebrating its 8OOth jubilee. The reconstruction of the Frauenkirche (Church of Our Lady) will take centre stage. During the Second World War, on the nights to the 13th and 15th of February 1945, large parts of the city and the Frauenkirche and the adjacent historic city centre were destroyed in bombing raids. As a result of national and international efforts the reconstruction of the Frauenkirche was finally officially given the go-ahead in 1994.
In tandem with the reconstruction of the Frauenkirche it was planned to recreate the old centre in its original location. In September 2002 an investor's competition was tendered. The tender for the re-building of the "Quarter by the Frauenkirche", "QF" for short, was awarded to the Investment Group including Arturo Prisco, a businessman from Munich, and Kai von Doring, an architectural office in Dresden.
Later a Dutch co-investor entered the project, represented by Kondor Wessles, a construction service enterprise. They are a member of the network that F.C. Trapp Bauunternehmung Berlin is also part of, who ended up being the general contractor for this project.
Spurred on by the idea of a resurrected Frauenkirche the investors demanded fast track building. The new construction of "Quarter 1 ", one of 5 quarters intended to revive the Neumarkt (Newmarket) as an urban ensemble, was accomplished in record time. Extensive archaeological digs preceded building works as nobody knew what lay hidden beneath the asphalt surface that was put over the area by the former GDR after the demolition of Dresden. During the excavations remains of walls and vaulted cellars that were completely intact were discovered and is was planned to incorporate these into the reconstruction works. Unfortunately, the floods of August 2002 put an end to those plans.
The laying of the foundation stone took place in October 2004 and since the start of 2005 intensive building is underway. Pre-cast concrete manufacturer Oschatz GmbH from Oschatz, situated about 55 km from Dresden, is responsible for the assembly of 2,500 m2 of pre-cast ceiling filigree elements and 4,000 m2 double skin walls in the basements. To prevent them from future flood waters these were constructed as "white tubs". The speed and quality of the concrete production and assembly were the main factors in keeping to the tight schedules. The Oschatz production site supplied a total of 35,000 m2 of pre-cast ceilings and 22,000 m2 of wall sections with high quality fair faced finishes.
Rudolf Mutze from MC specialist division Protection Technology, who has been servicing the Oschatz plant for the last 10 years, highlighted the importance of the cooperation on this project between MC and the manufacturer.
Using Muraplast FK 48 (a high performance admixture) and a mould release agent that was specially formulated for Oschatz, it was possible to achieve a very high degree of consistency and surface finish on the ceilings and walls.
In addition, Oschatz received the order for 50 staircases, 30 bearings, 110 ring beams, and several solid walls. Everything was delivered on time and without any complaints and was in some cases also assembled by our own installation teams.
The "Quarter by the Frauenkirche" has a floor space of 17,000 m2. Next to a five-star hotel sporting 61 rooms and a boutique the city ensemble also provides 38 exclusive flats, 39 retail shops, art galleries, 3,000 m2 of office space, 4 restaurants and bars/cafes and 200 parking spaces in an underground car park. A spacious walkway that has been described as having a 'Florentine flair' spans three levels and has a glass ceiling that gives a view of the spire of the Frauenkirche.
On the 28th October 2005, two days before the consecration of the Frauenkirche, the topping-out ceremony was held in a festive atmosphere. The first shops will open by mid 2006. With this reconstruction Dresden's Neumarkt is the only place in Dresden's Old City Centre that will have been restored as a holistic unit based on the original historic structure.
There's no doubt, the "Thuringian Forest Motorway" is extraordinary: Its route runs through the main ridge of the Thuringian Forest across the A 71 motorway from Erfurt to Schweinfurt and the A 73 from Suhl to Lichtenfels, thereby connecting the federal counties of Thuringia and Bavaria. The new 223 km long motorway boasts engineering feats of the highest order in short succession, which make this one of the most sophisticated traffic and transport projects of a reunified Germany.
Initil ground breaking was on the 16th April 1996 - kick-starting this ambitious project by the Federal Ministry for Transport, Building and Development, which is planned to be completed by the end of 2008, by which time the construction bill is estimated to total 5.05 billion Euros.
A particular highlight, however, is the 'Wild Gera" bridge, 552m wide and 252m wide, making it the largest reinforced concrete arch bridge in Germany. “Wild Gera” is regarded as an engineering masterpiece. Reaching 110m at its highest point, the bridge spans the valley of the “Wild Gera” between its two anchor points Grafen-roda and Oberhof. The aesthetically curved arch construction ensures the valley ground remains void of any columns, so that the bridge harmonises perfectly with the awe-inspiring scenery of the Thuringian Forests. It goes without saying that public interest in the construction was immense during 1998 and 2000.
The most expensive section of this construction project, however, was the crossing through the ridge of the Thuringian Forest between llmenau and Meiningen. Four tunnels with a total length of 12.5km had to be built on this 45km long strtch along the A71 alone. The are the “Rennsteig Tunnel”, the “Alte Burg”, the “Hochwald-Tunnel” and the “Berg Bock”. In all four tunnels the interior concrete lining was cast using the MC admixtures. Centrament N5 and Muraplast FK 43.
Similarly, MC admistures were also in demand for the construction of the bediges, delivering excellent concrete quality. Alkong the motorway stretch between llmenau and Meiningen 15 large bridges with an overall length of 7,481m were built. In ten of these constructions MC products were used, including Muraplast FK43, Centrament N5, Centrament Retard 360 VZ and Centrament Air 200. For the construction of the “Wild Gera” bridge alont, 40,000 kg of MC admixtures were used in the concrete.
The expansion of route A 73 saw eleven beidges with a total length of 4,124m being built with concrete admixtures from MC. Important partners during construction were: Cemex (formerly Ready mix). Rennsteigbeton, the company Hassel-beton and tbg Schleusingen. MC specialist advisor Marko Bergmann assisted the applicator firms in all technical queries concerned with concrete. He has been assisting in this large-scale project right from the start.
The Thuringian Forest Motorway closes a critical gap in the national German motorway infrastructure. In future the journey from Thuringia to Wurzburg and Stuttgart will be an hour’s drive less than previously, while the trip to Munich will be 45 minutes shorter. Today the traffic on parallel federal roads has already been cut by 40 percent, thereby putting less strain on the adjoining towns and villages. The hope is that this ‘closing of the road gap’ is also going to benefit the entire region in economic terms.
Since the end of May 2004 Warsaw has a new gem in its architectural crown. Situated in an attractive green belt near the Vistula is the new headquarters of Poland's Olympic Committee (Polski Komitet Olimpijski).
The new complex consists of four buildings that house, in addition to the Committee's administration, multipurpose function rooms, halls as well as restaurants and cafes, plus attractive terraces that allow splendid views of the city. The main purpose of this centre is the promotion of Poland's Olympic culture and to inform visitors about outstanding achievements in the history of sport.
The project, designed by Kulczynski Architekt Sp.zo.o, cost 6.55 million Euro to build. Special attention was paid to the aims and purposes of the building, which the architectural design of the prestigious main building reflects with great success. In line with contemporary architectural style, steel, aluminium, concrete, wood and glass have been skilfully combined to signify modern objectivity and transparency. The rounded building is reminiscent of a sports arena. An elevator shaft made of glass is the prominent external feature and coupled with a metal ceiling structure serves to symbolise the Olympic Flame.
Echo Investment Spolka Akcyjna from Kielce was chosen to realise this demanding project. Work started on the 11th October 2002. Right from the start, i.e. the laying of the concrete foundations, MC delivered concrete admixtures to Dyckerhoff Beton Polska, the executing contractor of the project. In addition toMuraplast FK 43 various other products from the concrete finishing range were used during the further course of construction works. MC's fairing products were implemental in achieving the visual aesthetics that the architect desired – a concrete surface that is totally flawless and perfectly uniform.
After London, Budapest has the second-oldest underground system in Europe. It was inaugurated in 1896 to celebrate the 1OOOth anniversary of the Magyar conquest of Hungary.
Today the underground network consists of three lines. Despite this local transport in the Hungarian capital has reached the limits of its capacity, so that the construction of a further line became imperative. On January 23rd, 2006 the contract for the construction of Line M 4 was signed by the Municipal Transport Services of Budapest (BKV).
By now the construction of the new underground track is in full swing. The 7.4 km long track runs under the Danube and connects the town districts of Kelenfold and Rakospalota. It is scheduled to open by mid 2010. Equipped with the latest control and safety technology for driverless operations the M 4 will be the first fully automated underground line in Hungary.
The order for this large-scale project was given to BAMCO, a company syndicate to which the STRABAG Group also belongs, amongst others. Executing company for precast concrete components for the segment lining of the underground tunnel is Zipp Bratislava S.r.o., which has been part of the STRABAG Group since 2004. It is one of the leading construction companies in Slovakia and has more than 40 years' experience in the development and production of precast concrete components.
The order comprises the manufacture of a total of 4,000 segment rings, with each of them consisting of five segments and a finishing segment. High demands are made on the segment production in terms of precision.
The concrete quality of the units is also of paramount importance. Hence the mix design must be tailored to the individual requirements of the construction project and must be extensively tested for suitability.
Many well-known manufacturers tendered for the supply contract of the concrete admixtures. In the last round MC-Bauchemie was able to leave the competition behind. The deciding factor was the exceptional product quality. Required were, amongst other things, a high sulphate resistance and rapid strength development, since the precast component production is performed in two stages. Based on experience and comprehensive research and development work MC was the only supplier capable of achieving the strength without the aid of accelerators. The decision was preceded by numerous practical tests. After successful completion the final formulation was checked by the renowned MPA Berlin-Brandenburg and the suitability of the concrete for the ambient conditions subject to heavy chemical attack was attested.
The order for the production of the concrete rings spans three years. First samples were produced in December 2006 and since February 2007 the production has been carried out at the Zipp concrete plant in Sered in Slovakia.
The smooth and successful progress of this large-scale project is based primarily on the cross-national cooperation between MC Slovakia and MC Hungary and the long-standing contacts with the executing companies. Michael Lehky is the contact for Zipp in Slovakia and Csaba Peth0 from MC Hungary assists in the project on site.
Since the beginning of July 2006 the municipal sewerage company (StEB) Cologne has been building an additional storm water sewer in the Industrial Park North in Cologne-Niehl. It is one of the most important water projects in the north of Cologne.
The pipe lies at an average depth of 14 m and when completed will have a total length of around 2,000 m. The construction of the project will last until spring 2008.
The structure is in many ways a project of superlatives. Especially the first part of the pipeline route proved to be challenging. In this section several track structures, a bridge and a site with highly sensitive measurement instrumentation had to be underpinned.
The concrete pipes to be installed also pose a technical challenge due to their sheer size. Based on their many years' experience the E+F GmbH Rohrwerk Epiton in Hunxe received the order to produce 375 pipes with a length of 3.5 m and 320 pipes with a length of 1.9 m. Each pipe has an internal diameter of 3.4 m and an external diameter of 4.4 m. The sections are designed with a 100 year life span. Each pipe had to be moved using heavy load transportation from Hunxe to the construction site in Cologne. In total12,000 m3 of concrete were used, supplied by Elskes Transportbeton GmbH in Hunxe. To achieve the desired segment qualities the concrete mix was designed incorporating Centrilit Fume SX. This silica fume slurry enhances concrete density and resistance to chemical attack and corrosion.
The workability of the concrete, matched to the production process, was achieved with a modern high-performance flow agent on PCE basis and achieved a consistently smooth surface finish.
In a project of this scale good cooperation between the companies involved plays a vital role. MC has for many years had good relationships with both companies. The partners complimented MC's individual and extensive product solutions which successfully met all the requirements of this project.
The continuous rise in energy consumption all over the world and the negative changes to our climate as a result of using fossil fuels necessitates the urgent need for the development of renewable energy sources.
Being the host of the World Climate & Energy Conference Brazil is paying particular attention to environmental protection and resource preservation. As in Germany, targeted political measures are intended to promote the development and utilisation of renewable energy sources. PROINFA, the energy supply law passed by the Brazilian government a couple of years ago, laid the foundation for the expansion of wind power. It is estimated that by the end of 2006 investments in Brazilian wind power plants will reach approximately 5 billion BRL (roughly 1.4 Billion Euro).
One of the wind power projects that is subject to PROFINA regulations is the 150 MW output wind power plant Osorio, run by Ventos do Sui, a subsidiary of the Spanish Elecnor group. On its completion at the end of 2006 it will be the largest wind park in Brazil. It comprises 75 wind energy plants and one day the plant will be supplying energy to 1.5 million people. In 2005 Osorio was awarded 1st prize as the "best renewable energy project in Latin America" by "Euromoney" magazine.
Wobben Wind Power is the supplier of the wind power plants. It is a subsidiary of Enercon GmbH, the global market leader in the sector and a company that MC successfully cooperates with in Germany, mainly supplying concrete admixtures.
The almost 100-m high precast concrete towers are constructed using a pre-stressed steel technology, specially developed by Enercon, whereby the individual tower segments and the foundation are braced as one inextricable unit. Archei Engenharia, a Brazilian company with more than 45 years' experience in construction - primarily in infrastructure projects- has been chosen to carry out the work.
Based on good past experiences during other joint projects in Brazil and because of the very high quality requirements Archei requested MC Brazil's assistance in the selection of suitable concrete mix proportions for the towers' foundations. The enormous height of almost 100 m meant that each tower foundation required around 500 m2 of concrete.
In various laboratory experiments the MC admixtures "Muraplast FK 22" and "Centrament N 5" performed best, so that MC received the contract for the delivery of the concrete admixtures. Jaques Pinto from MC Brazil and Manuel de Sa from MC Bottrop, are responsible for the supervision of this project. During the construction phase between November 2005 and June 2006 the technical support of MC staff was frequently called upon.
Wind energy in Brazil is still in its infancy, so that further investments in this sector over the coming years are anticipated.
Airports are the figure - Modern parking heads of a town and their architecture and technical facilities determine to a great extent their international image. For this very reason quality considerations override all else when a new airport is built or an existing one is restored or extended.
Airports are of particular importance for MC: firstly they connect MC’s global operations and secondly, they offer great application potential for the various MC product systems, which can be found in many different areas of national and international airports. Thanks to MC’s competence in all matter concerning concrete technology it can boast an extensive reference list in this sector.
On this list are, for instance, the new assembly hall of the wide-bodied airbus A 380 in Hamburg, the multi-storey car park in Zurich and the expansion of the Warsaw airport. In addition, MC has also participated in many large-scale airport projects all over the world, namely in Dresden, Dusseldorf, Frankfurt, Leipzig, Munich, Athens, Dublin, Kiev, Copenhagen, Prague, Rome, Sao Paulo and Vienna. In addition to Warsaw the Polish reference list can boast several airports: Gdansk, Posen and Stettin.
The diverse areas of any airport are characterised by the fact that they are subject to ultimate stress impacts caused by people and technology and that they have to keep up with an adjust to the growing demands in terms of technology and aesthetics. All the while safety has priority, which sets high benchmarks for the materials and systems used. Extensive test procedures are frequently under-taken to check that they are fit for purpose and meet quality requirements.
The tarmac and runways have to endure enormous mechanical stresses caused by take-off and landing of aircrafts. De-icing agents add to the problem during winter months. For this reason special concretes used in road construction are employed here as well. In order to ensure safety, the concrete surface in aviation must have a constant and sufficient tyre-grip. To this end, best results were achieves using “Muraplast” as a plasticizer and “Centrament Air” as air-entraining agent, as can be seen in the example of the expansion at Stuttgart’s airport. In Stuttgart the runway had to be relocated by 1.4 km to the east in order to fulfil international criteria.
Parking garages at airports are not just there to provide travellers with parking for their veicles; they also have to meet the technical and aesthetic demands and should harmonise with the entire airport layout. A most impressive example is the newly-build parking garage 3 at the airport Zurich Kloten, covering an area of more than 95,000 m². A prominent part of this modern concept was the visually appealing design of the floor under consideration of the technical requirements. Concrete surface protection that complied with the latest construction regulations had been stipulated. This included resistance to wear-and-tear, fuel, cleaning agents, chemicals and changes in temperatures. To prove traffic ability, MC has developed an elaborate traffic ability test course, which was able to simulate the load from vehicles on the parking garage surface.
The ideal solut8ion turned out to be coating systems on a reaction resin basis (MC-DUR), which performed convincingly on all points.
The innovation concrete admistures, concrete repair systems and industrial floors from MC also play an important role in the repair and expansion of airport buildings and assembly hangars in satisfying clients’ technical and aesthetic requirements. Airport construction is highly demanding for both planners and operating companies in terms of logistics and rapid execution. One more reason why sounds experience and good communication between all project partners is essential. With competent specialist advice and trend-setting technology MC is here yet again a significant contributor to the smooth running of such large-scale projects.
Situated right in the centre of Cologne, the Rhine Garden offers both locals and visitors a very attractive recreational area. Where once long queues of cars edged their way slowly along a broad road alongside the river Rhine, one now find a variety of possibilities to while away the time and have fun. Now, Cologne's Old City is again lying right by the side of the river embankment.
This was made possible by the construction of the Rhine Embankment Tunnel, which was completed and opened to the public in November 1982, following more than three years’ of construction work. Since then the tunnel carries traffic 600 metres along the Rhine, right underneath the Old City Centre.
After 24 years in use the tunnel had become an urgent need of cleaning and repair work. The ‘city fathers’ intended to give the tunnel a cleaner and brighter look, which would also make driving in the tunnel safer. The relevant office for bridge and city railway construction for Cologne specified in their tender that the building repair measure should use a structural PCC II mortar (category M3) with fire protection class F90 as well as a lasting surface protection system.
Prior to the tender MC had already been contacted by the authorities in Cologne and had been asked to assist in the selection of suitable products. Several applied colour samples had been products for this purpose in order to introduce the “Emcephob Surface Protection Systems”. Already during this project phase MC convinced the authorities with its performance spectrum and MC products thus became the basis for the tender.
The tender earmarked Nafufill as mortar and Emcephob NanoPerm P as coloured concrete Protection for use in the project. The latter not only provides permanent protection from dirt, from attack by deicing salts and climate, but also protects from unsightly graffiti. A particular advantage is the ease with which graffiti can be removed using Emcephob Basic Cleaner from the matching Emcephob ranbge – without leaving blemishes. The surface is preserved in terms of technical construction, while at the same time retaining its aesthetic value.
For the execution contract the office for bridge and city railway construction Cologne contracted a consortium, consisting of the companies Hans Tiefenbach, Duisburg, and Julius Mieden, Bottrop. Repair works lasted during October and November 2006 while the tunnel was kept open for business as usual. To minimise obstruction to traffic, work was carried out in multi-shift operations and during night time.
As a first step the entire concrete surface was thoroughly cleaned and substrate preparation was undertaken, followed by the repair to the concrete with Nafufill Km250. Then a coat of fine mortar, Nafufill KM103 was applied to the whole concrete area, which was then finished off with the surface protection system Emcephob NanoPerm P. The light grey colour, selected by the client, has greatly improved the light conditions in the tunnel.
On the whole, the restoration work on the Rhine Embankment Tunnel has without doubt made the City look even more attractive. The bright and friendly finish has the added benefit of improving driving attitudes, aiding traffic safety as a consequence.
In order to stay abreast of its global economic activities and to accommodate future growth, the LeipzigjHalle airport will be expanded by 2008. LeipzigjHalle airport is DHL's (Express service subsidiary of the Deutsche Post World Net) main European trade centre. The expansion will provide sufficient capacity for a steadily growing air freight volume and will also provide excellent logistical connections with road and rail networks.
Around 160,000 deliveries will in future be sorted and distributed every day. This corresponds to a freight handling of over 2,000 tonnes per night. The DHL terminal is close to the new south runway which, at peak times, can accept up to 52 freighters. Capacities are sufficient to enable the handling of what will be the largest cargo plane in existence, the Airbus A380.
The pre-condition for DHL's move from Brussels to Leipzig was the construction of the 3.6 km south runway, running parallel to the existing north runway. The 2-year construction project is due for completion and will be operational in the summer of 2008.
To ensure that the pavements will resist the detrimental effects of de-icing materials, all concrete roads and runways are constructed using air-entrained concrete. MC secured the supply contract for the necessary admixtures based on its high-quality products, excellent references in road and infrastructure construction and its flexible but reliable logistics. MC's good working relations with the consortium companies, Heilit & Woerner and Max Bogl, were a deciding factor when appointing an admixture supplier. In order to meet the tight deadlines, the concrete works were carried out within a two month timeframe during October and November 2006. An optimal logistical organisation was demanded from the concrete suppliers, so that the specified area of 250,000 m2 could be concreted with 100,000 m3 of concrete. Every hour between 250 and 300 m3 of concrete had to be produced, transported, placed, finished and cured. For MC this translates into a supply of 220 tonnes of concrete plasticizer Muraplast FK 19 and 35 tonnes of air entraining agent Centrament AIR 202. A further 80 tonnes of MC curing agent, Emcoril B VM, were also supplied. This agent is sprayed onto the concrete immediately after application and forms a film, preventing excessive rates of water evaporation which could lead to desiccation and surface cracking.
The conclusion upon completion of the concrete works on the new south runway was that at no time had here been any fluctuations in the concrete quality with regard to the air content or workability.
The construction project "Floating Concrete" demonstrates how versatile and durable concrete actually is.
A floating dock made from 28,000 tonnes of concrete has been specially created for the Neptun Dockyard in Rostock, an affiliated company of the Meyer Dockyard Papenburg. Normally, steel is used for this type of construction. Since material, maintenance and operational costs are lower and the construction time is shorter, concrete was used here for the first time.
The ground-breaking construction made from precast and site-mixed concrete is 150 metres long and 55 metres wide. A base plate holds 160 individual "honeycombs" measuring 13.5 by 3.5 metres. The cell membranes are 8.5 metres high and consist of a combination of precast concrete, semi-finished precast elements and site-mixed concrete.
Sinbobeton Papenburg; as ready-mixed concrete company of the Sievert construction group, was contracted to deliver around 5,000m3 of concrete. Since no prior experience for a construction of this type existed, a special concrete mix design had to be developed for this project. Based on MC’s great competence in the area of concrete technology, MC and the testing laboratory Haren were jointly involved in the development process. The various tests showed MC’s plasticiser Muraplast K-Plast 41 as the product giving the best results.
The extraordinary pontoon was manufactured in just three months in two separate parts in succession at the outside dock o the Meyer Dockyard in Papenburg. These were then towed across the River Ems, the North Sea, the Kiel Canal and the Baltic Sea to Rostock where they were finally joined together in-situ. Since then the floating dock has been put into operation and is capable of servicing ships with up to 23,000 gross register tonnes.
The innovative “Floating Concrete” project is of particular interest to MC as it may set a future trend due to the novel use of concrete.
At MC every tenth employee works in Research & Development. Application-oriented fundamental research is being carried out at MC's modern and highly successful laboratories. Customers' problem scenarios and requirements prompt new product development at MC.
Some examples of the successful innovations are
Polycarboxylateethers (PCE) are the third generation of the so-called super plasticizers and are the most up-to-date and efficient concrete admixtures. They are mostly synthetically produced modified copolymers. The raw materials are petro chemical based.
As petro chemicals are becoming increasingly expensive and will eventually disappear altogether the search for renewable alternatives has assumed a high priority.
Within the framework of projects funded by the Deutsche Bundesstiftung Umwelt (DBU) [German Federal Environment Fund] various approaches were pursued with the aim of producing PCEs using renewable raw materials. This would make a positive contribution to climate change by reducing C02 emissions. The projects lasted for around three and a half years. MC's partner in this project was the Institute for Construction Material at the University of Hanover under the direction of Prof.Ludger Lohaus.
Natural raw materials used were coconut oil, palm core oil, sebaceous oil or palm oil. In order to reduce the high component of polyethylene glycols in PCE, ethoxylized fatty alcohols, such as those based on Iaurin alcohol, were used in the PCE compositions. After dilution with water to reach a viscosity common in practical use, its properties such as liquefing effect, stiffening, air pore content and early strength in accordance with DIN EN 934-2 and the norms stated therein were compared with commercially available PCSs based on petro chemical raw materials.
A 100 percent substitution of glycols based on petro chemicals was chemically impossible. Subsequent tests with blends of fatty alcohols and glycols as starting materials for the composition of the polycarboxylate then led to success.
Four different new plasticizers were developed that were all based on renewable raw materials.
A relatively uniform performance in terms of spread or flow and workability retention was achieved. Hardened concrete properties such as compressive strength development and air content were comparably good with the various products.
Other properties of the hardened concrete incorporating the new raw materials were similarly compared and there was no difference in resistance to carbonation, resistance to freeze thaw cycling and de-icing agents.
Proceedings, based on a life-cycle analysis, conformed to the standardized procedure in accordance with DIN EN ISO 14040.
The evaluation of the potential environmental burden was carried out based on selected effect categories that were expected to bring representative and meaningful results. In the foreseeable future, when the unlimited availability of fossil resources is no longer a given, this procedure is going to have significant ecological advantages compared to petro chemical approaches.
The above mentioned documented results certify the newly developed PCEs on fatty alcohol basis being principally of equal value. The pore structure of the tested concretes was – when using the new flow agents – more homogenous and reached a higher level of micro air spaces. For the first time it was therefore possible to substitute petro chemical starting substances with renewable raw materials and to carry out a start into the long-term development of flow agents and to put it into practice.
The crossroads at the Pragsattel is one of the busiest traffic junctions in Stuttgart. Day in day out around 110,000 vehicles frequently cause long traffic jams and pose an enormous burden on residents and the environment. The construction of a tunnel was aimed at easing the traffic permanently. The project developed for this purpose, "810 Pragsattel/lowentor" is part of a comprehensive new traffic concept for the city of Stuttgart.
The client is the Technische Referat/Civil Engineering Office of the region's capital, Stuttgart. The order for the construction work went to Arge Ed. Zi.iblin AG I Gebr. Fahrion GmbH. The biggest challenge was to ensure the smooth running of the construction works while keeping traffic running at a steady pace. This required the highest level of know-how and detailed process planning. For instance, pipes and services in the construction area had to be relocated and the traffic routing and tramway lines had to be adjusted to the progress of the construction several times.
The construction of the tunnel itself was performed using open cut tunnelling. The excavation, up to 20 metres deep, was stabilised on the sides by sheet piles and large bored piles. At intervals of ten metres, sections of reinforced, water proof concrete formed the base, walls and roofs. Total volume of concrete was about 50,000 m3. When the structural work was completed, the interior work began, fitting the tunnel with the latest safety technologies. The B10 Tunnel has one tunnel in either direction, consisting of two lanes each and is 720m long in total.
Constructing tunnels requires a high degree of technical competence. In terms of performance, implementation and location-specific influences, requirements vary greatly as to which concrete systems may be used. In order to design a concrete admixture system that matched this project to perfection, BBQ Bautechnik in Baden-Wurttemberg GmbH, Stuttgart, prepared different concrete mix designs with admixtures from MC in the run up to the project. The relevant suitability tests were then carried out in Fahrion's laboratory, assisted by MC concrete technologists. The best results were achieved with Muraplast FK 63 1 7 and Centrament Air 205. Ortolan SEP 711/791 was used as a mould release agent. Concrete supplier for this project was TBR Frischbeton Stuttgart GmbH & Co. KG.
A product system that fulfilled requirements, competent customer support and good cooperation between the companies involved, have- in spite of difficult circumstances - enabled the smooth progression of the concrete works.
The know-how gained over more than 40 years of working in the area of concrete technology has made MC one of the leading suppliers in modern tunnel construction today. Numerous large-scale projects, such as the Elb Tunnel in Hamburg, the Herrenberg Tunnel in Lubeck, the BAB 17 Tunnel near Dresden or the road tunnel in the Polish Bialystok are testimony of MC's performance capability.
Surrounded by large shopping centres Essen, too, gets its own attractive shopping mall. Right in the city centre at the Limbecker Platz, formerly the Karstadt premises, a shopping area of over 70,000 m2 is being built. 300 million euros have been invested in this new shopping paradise, creating 2,000 jobs and making this the largest inner city shopping centre in Germany. The first building phase was completed in time and celebrated with a public opening on the 13th of March; the second phase is scheduled for completion in 2009.
It is not just the size that impresses, but the extraordinary architecture which makes the shopping mall Essen's new landmark. Munich's star architect, Gunter Henn, was inspired by Marilyn Monroe's iconic wind-blown skirt scene from the famous movie "The Seven Year Itch". He designed a facade panel with a silver glow covered with lenticular sequins that reflect sunlight during the day and are illuminated in colour by night.
The ambitious large-scale project is realised by Arcandor AG (formerly KarstadtQuelle AG} and the Hamburger ECE in cooperation with Union Investment Real Estate AG. The main contractor is Bilfinger Berger AG. A project of this scale, situated right in the city centre and with an estimated record breaking construction time of only three years, represents a construction-logistic challenge for everyone involved and requires competence and know-how. Here, moving vast quantities of building material to and from the site and the execution of the road works have to be carried out during ongoing traffic. At times up to 800 people are working on site.
800,000 to 1 million tons of material is going to be used during the three year construction period, including 120,000 m3 of concrete. This corresponds to almost 20,000 truck mixer loads. This quantity is being provided in a supply cooperation between Dyckerhoff Beton, Cemex and Heidelberger Beton, who will be supplying one third each.
For MC the involvement in the project at the "Limbecker Platz" is a home match. As a partner of Dyckerhoff Beton, subsidiary Rhine-Ruhr in Essen, MC provides high-performance plasticizers and super plasticizers ensuring a reliable ready-mixed concrete quality. In such a vast amount of concrete quality and consistency is of particular importance for results. For this reason the raw materials for this project were pre-tested with MC admixtures to achieve optimum performance. MC's local presence enabled, especially for this project, support and precise logistic coordination, matched to the project progress. Rainer Standler from Construction Chemicals was at hand to provide competent customer services.
In 2009, when the second construction phase will also have been completed, a shopping experience- centre of superlatives will be welcoming around 50,000 customers a day.
Especially since the 20th century concrete technologists have been busy developing progressive technologies and cost-effective possibilities to improve concrete properties. In this respect the admixtures and aggregates used play an important part. PCE (polycarboxylate ethers) based plasticizers, for instance have distinctly altered the ready-mixed and pre-cast concrete industries in the past years. For years MC has been conducting research into these PCE materials and is developing targeted problem solutions for the pre-cast and the ready mixed concrete industries. The latest success of such activities has led to a new generation of high-performance plasticizers marketed under the product name MC-PowerFlow. These products are exclusively based on specially developed innovative MC raw materials. Each new product generation expands the limits of what is possible in technical terms.
In the pre-cast concrete industry the demands on early strength development has priority. With the MC-PowerFlow generation considerably shortened formwork stripping times can be achieved. This saves time and money. Furthermore, the use of the product leads to a smoother and blemish free surface finish. These cost-effective advantages offer especially good future prospects for demanding large-scale projects. One example is the cooperation with Enercon, the world's largest manufacturer of wind turbines. The towers for such plants reach ever greater heights and can only be realised using high-performance concrete. To meet all Enercon's requirements MC developed MC-PowerFlow 1114. It is the result of intensive cooperation between MC and the customer which has already led to several individual concrete formulations in the past.
Totally different requirements on a high-performance plasticizer are made by the ready mixed concrete industry. Here it is necessary that the setting or stiffening process of the fresh concrete does not start until the concrete has been transported, placed, compacted and finished. To achieve this it was customary to add admixtures on site but the new technology makes this risky procedure redundant. The concrete must arrive onsite in the desired target consistency. With MC-PowerFlow the production of concrete of any consistency can be achieved without making any concessions to the properties of the hardened concrete.
These economic, time and product relevant advantages of PCE plasticizers of the latest generation are becoming the deciding factor particularly when it comes to tenders for large-scale projects. MC-PowerFlow products were used in three high profile projects in Dusseldorf by the leading international contractor, Hochtief, and impressed the client. On the Hafenspitze project 18,000 m3 of concrete are planned to be used by 2010. Two towers of 90m height each are being built there, as well as an office complex and a hotel of the Hyatt chain. A further project is the 6-storey building of the Federal Constabulary, which after completion in 2009 will be the size of 12 football pitches. A construction of superlatives is also the "Sky Office" at the Kennedy dam. For this office building with 23 storeys approximately 30,000 m3 of concrete will be used by 2009.
These projects are just some examples for the rising demand worldwide for innovative plasticizers for concrete production and application. However, it is not just MC's technologies that impress. The above average competence of MC employees in matching formulations and giving sound advice onsite are also decisive in securing the contract of any project.
Concrete is an indispensable part of our modern work. There is no alternative for this mass building material which has been around since antiquity. If concrete had never been invented we would be forced to build using steel, stone and timber – our world today would look quite different. Technical progress continually optimises the basic knowledge of ancient times and with contemporary development and test processes concerts it into modern high-tech systems.
The excellent properties of concrete are based on its almost limitless availability, limitless malleability and durability. Due to its economic and ecologic importance concrete is going to remain one of the most important building materials for the future, too.
The beginnings of concrete technology date back more than 2000 years and the material is constantly being adapted to meet the requirements of modern architecture and the environment. This is only possible through the use of modern admixtures and aggregates.
The use of additives in concrete production is as old as construction using concrete itself. Even the builders in antiquity used additives in order to make the building material particularly resistant.
Concrete is generally known as a three-substance system made from cement, water and aggregates. By way of enriching the base material with admixtures and aggregates that influence the fresh concrete properties and the chemical physical properties of the solid concrete one talks today of a multi-component system which may contain up to ten components.
The targeted development of cements, admixtures and aggregates have revolutionised concrete technology. Today it is for instance possible to develop high-performance concretes with which sky-scrapers of over 800m height can be built. Pre-stressed concrete bridges many kilometres long create modern traffic connections across rivers and straits.
The high-performance concretes used for such projects differ by way of at least one outstanding characteristic to normal concrete. As self-compacting concrete for example only flows and compacts under the influence of gravity. In the chemical industry acid-resistant concrete (up to pH>3) is used. Seawater structures can be protected from penetrating waters and salts by using high-performance concretes.
To meet requirements of any kind the concrete must have a particularly dense structure. Usually this is a result of a combination of a low water/cement ratio with high packing density of aggregates and fine materials. To this end fine silica dioxide particles of the silica dust deliver the crucial contribution as additives. Furthermore, plasticizers based on polycarboxylate ethers are added to the mixture in order to reduce the water/cement ratio.
The silica fume technology has been around for about 20 years. Thanks to 40 years of competence in the area of concrete technology MC is today one of the few suppliers in the world that is able to offer such high-performance product systems. For ten years the silica fume suspension “Centrilit Fume S” has been internationally successful system.
The microscopically fine, perfectly graded granular structure fill the microscopic cavities between the cement particles. This improves the adhesion between cement matrix and aggregate grain and reduces the pore volume. This way high impermeabiliy and low porosity is achieved, which in turn are the significant parameters for lasting durability.
Silica fume is an industrial by-product of silica and ferro-silica production. Depending on the production process the silica fume possess different compositions. However, as an industrial by-product silica fumes are hard to come by.
The next step in concrete technology is therefore the targeted synthesis and production of aggregates. In this regard specially defined production properties can be set that will optimise concrete properties further still. It is for example possible to develop the so-called “Ultra High Performance Concretes” (UHPC). These concretes show a high resemblance to high-strength ceramics in terms of properties. Their properties are however vastly superior of those of normal concrete.
This development step has been possible because of the use of novel additives. The base substance is a layer silicate that is terminally treated. This changes their properties o that it acts as latently hydraulic or as a pozzolanic surface. The layered silicates are natural materials found in the earth’s crust whose availability is practically limitless and whose properties can be modified to suit.
These so-called alum silicates are pebble and clay-containing substances. In contrast to silica fume the alum silicates don’t form a gel in the alkaline pore solution of the cement matrix, but act as crystal nuclei in the finest pores. Due to the platelet structure a “reinforcement” in the nano area develops that could also be described as “crystalline micro structure” or “nano crystallisation”. High-performance concretes constituted like this possess better application properties and offer a better resistance to the exposure substances they are subjected to.
The fundamental differences between the silica and the nano-crystalliser technology lie in their chemistry and their material’s crystallographic structure. In mineralogical terms silica dust is amorphic, while the alum silicate has an orderly crystalline structure with a typical morphology.
The new high-performance concrete with Centrilit NC based on nano technology will soon find use in all areas of concrete application that require superior performance. These include the construction of wastewater treatment plants, sewer systems, industrial plants of the chemical industry, agricultural bio-gas plants and structures used in the waste management industry. Furthermore, the ultra-high-strength concretes are expected to have a promising future as a composite material in the pre-cast industry.
In Singapor the supply of sufficient quantities of drinking water represents one of the biggest challenges for city-state.
The highly developed island microstate relies on water imports. So as to improve self-sufficiency, and protect the groundwater, the treatment of wastewater is to be pressed ahead with, in addition to utilising rain water more effectively.
Against this background Singapore’s state-owned water agency PUB (Public Utilities Board) has started extensive infrastructure projects in order to restore the pipeline network. Both public and private sewage networks in Singapore are in a dilapidated state due to ageing. This harbours considerable dangers for ground water and water ways.
To carry out the extensive repair measures PUB was searching the international market for a company with proven competence in this specialist area. As one of the leading global suppliers of repair systems MC’s specialist department ombran possesses many years of technical know-how and experience in the area of modernising and repairing sewage pipelines and manholes. MC impressed both in terms of the performance capability of its products and systems and in terms of service provision. PUB demanded high quality and environmental standards of materials and application, while products also had to be user-friendly and yield high coverage. The aforementioned properties had to be evidenced by way of a reference list and certifications from official bodies. In addition, intensive technical support and training of applications was provided by MC.
The project started in 2007 and is planned to be completed in 2010. The repair works are carried out in three phases. For the cladding of the over 3,000 pipe shafts the newly developed ombran MHP from the range of the tried-and tested specialist ombran mortars was used in this rather demanding project. This one-component, polymer-modified repair system is reprofiling and coating in one – an economic and time-saving advantage of great value in such a large-scale project. Where the wastewater pipelines were not walkable or accessible, the Konudur CIPP method was used over a stretch of 30km lengths to repair the pipes and achieve a longer service life.
Following completion of these extensive restoration works the sewer network is going to play an important role in the water supply of the city-state.
Until only a few years ago about 60 percent of the drinking water required in Singapore was furnished from groundwater and collected rainwater. PUB now aims at increasing this amount substantially. In principal, tropical rainfall is sufficient in providing what’s needed. However, the climate change between periods of monsoon and dry spells a means that periods of heavy rainfall are usually followed by long dry periods bar any rainfall. The heavy downpours’ that fall during the monsoons usually product large quantities of rainwater which tend to flow directly into the sea.
In the future PUB wants to prevent this and intends to collect the previous water in dams before it can enter the sea. To this end construction of water reservoirs are planned near the mouths of the rivers Punggol and Serangoon to increase the recapture of the precious rainwater.
The tender of this technically demanding project specified high-performance concrete that is water-impermeable and resistant to damaging processes.
For the supply of concrete admixtures technical competence had to be evidenced by providing a reference list of comparable projects. MC was awarded the contract due to being able to fulfil all specific technical requirements and based on the technical competence of MC staff. Deciding factor for being awarded the contract was the large number of successfully completed construction projects in the area of water management worldwide. Centrilit Fume SX, Muraplast 120 S and MC Special DM are used to products a total of 45,000 m³ of high performance and other concretes. The construction of the dams is carried out producing individual sections and connection joints, waterproofed with MC injection technology.
For years PUB has been very committed in achieving its objective of improving Singaporeans’ quality of life by ensuring clean rivers and waterways. MC was able to contribute to their cusses with expertise and efficient product systems.
Project management of both projects lay in the capable hands of Willie Kay and his committed team, including Tony Yap and Alan Tan.
Holidaying on cruise ships are the in-thing and dockyards around the world benefit from the rising demand. Until 2012 the Meyer Dockyard in Papenburg, Lower Saxony in Germany, will be building three large cruise liners per year.
In order to retain international competitiveness in the long run in this highly competitive market, this old-established company has made substantial investments. One of the most important measures has been the expansion of graving dock II so as to be able to accommodate the dimensions of contemporary cruise liners. Having started operations only in 2002, the hall was extended by a further 120 m. With its extraordinary size of 504 m in length, 125 m in width and a height of 75 m the Meyer Dockyard is now the biggest roofed dockyard in the world.
The particular challenge in extending the yard was to deliver and place 41,000 m3 of concrete between December 2007 and December 2008.
8,500 m3 were needed as underwater concrete just to secure the foundations. This amount was placed in an 84- hour long, non-stop concreting pour using tremie pipes, whereby the concrete is poured through vertical pipes at respective locations making sure the bottom pipe end remains below the fresh concrete surface during the entire concreting process to avoid wash-out and segregation.
The concretes were provided by the supply cooperative Sibo-Gruppe GmbH & Co. KG plant Papenburg and ROVA-MIX GmbH & Co. KG Varel. Consistent quality was the deciding factor in concretes of such large quantities. Concrete admixtures were supplied exclusively by MC based on the convincing pre-trials. Advice and project support on site was provided by Tobias Rieger from SC Nord; in concrete and lab-technology questions Tobias Rieger received assistance from the department Application Technology in Bottrop.
The harmonious cooperation between the companies involved ensured the project was realised without a hitch and in good time.
In the production of high-quality concrete goods that are taken from the formwork immediately after compaction the early strength of the concrete mix is decisive. Here MC was able to come to the aid of a Hungarian concrete goods manufacturer who had changed production technology by supplying a special additive that ensured better compaction and surface quality of the machine-made products.
The family-run business betonEPAG, based in Tokol, 25km south of Budapest, has in addition to producing cobble stones specialised mainly in the production of hollow blocks. With an annual production output of over 5 million units the concrete goods manufacturer is one of the market leaders in Hungary.
Until 2008 the production of the hollow blocks still took place out in the open. The concrete composition was filled into the moulds with a conventional compactor, was shaken and compacted, was deposited for drying right there and then not moved again until it had totally work hardened. This meant that the products' exterior surfaces were unprotected and exposed to the weather. The method did not only result in a loss of quality, but more importantly brought production to a complete standstill in the winter or at times of bad weather.
To increase productivity and quality and in order to ensure the company's future and continued growth the owner family decided to modernise production and moved it into a production hall. At full capacity the new plant now achieves an annual output of 7 million hollow blocks, which represents an increase in productivity of around 100%.
Filling, vibration and compaction of the concrete mixture is now done automatically on feeder planks that are transported via conveyor bands and conveyor vehicles to a drying warehouse where they remain for 36 hours. After that they are ready for palletisation. In this fully-automated production process the "fresh" blocks are relocated immediately after being put down. This caused deformations in the still earth-moist, so-called "green" concrete, resulting in a scrap rate of over 20 percent.
Concrete expert Sebestyen Zsolt from MC Hungary visited the plant to get a first hand picture of the production process and together with the customer ran a number of tests. The task was to select an admixture whose mode of action would meet the particular requirements of hollow block production.
Because of the structure of the composition and because of compaction air pockets must be expelled from the concrete microstructure to ensure a sound "green compressive strength". This in turn is the precondition for a sufficient "green strength" that ensures the dimensional stability of the hollow blocks. The ideal admixture in this case turned out to be Murasan BWA 14, also in terms of clock cycle. The chemical-physical mode of action of the special additives added to the mixing machines produced an extremely fine distribution of the cement paste having a lubricating effect between steel formwork and concrete during the production process, so that a high-quality sealed surface finish could be achieved. Besides a clean and smooth surface the blocks also featured a high firmness when coming out of the forms.
Based on its combined mode of action Murasan BWA 14 provides the Hungarian concrete goods manufacturer with a high production security that features an extremely low scrap rate of less than 0.5 % and a visibly improved product surface.
By now MC concrete admixtures are also successfully being used in Tokol for the production of cobble stones. For this specific application MC also has the appropriate solution: in this case Murasan BWA 16 is used, whose mode of action ensures quality consistence and a smooth surface finish after curing.
With modern materials and manufacturing processes it is possible today to produce ultra-high-performance concrete or UHPC. In the process all parameters of the concrete formula must be optimised using computerised modelling. With the product system Centrilit NC MC-Bauchemie has developed a novel material based on an alumino-silicate that improves material characteristics on a nano scale in the cement matrix. Jointly with the engineering office G.tecz in Kassel/Germany it has been possible to develop a material that has almost ceramic-like characteristics.
Concrete is classed as ultrahigh strength when its compressive strength lies above the strength category C 100/115 as specified under DIN EN 206-1. Compared with standard concrete a whole range of concrete-specific parameters have to be set for this concrete quality. The reciprocal effects between the mix components have proven particularly complex. Given optimal composition and adherence to special quality assurance measures compressive strengths of up to 250 N/mm2 can be achieved even under site conditions. Thermal after treatment is under development that may make compressive strengths of 800 N/mm2 possible.
Compared with standard concrete, structures made from UHPC show 30% to 50% lower dead-weight. The high strength makes significantly lighter, more delicate and yet still highly load-bearing and durable concrete constructions possible. This means more aesthetic column structures in halls and more useable space and thinner walls for residential buildings. Furthermore, UHPC has an extremely high structural density that shows almost no pores at all given optimal production and after-treatment. While normal strength concrete usually has a 15 Vol. % capillary pore share, UHPC only has 1.5 to 1.8 Vol. %.
This means ultra-high strength concrete is virtually impervious to liquids, gases and chlorides. This enables it being used in concrete-aggressive areas such as water supply and wastewater plants. For a long time increasing the compressive strength was the main objective in UHPC development, nowadays importance has shifted to concrete's specific values such as elasticity modulus, tensile strength and durability.
Until now concrete additives such as silica fume were used for high-performance concretes. With the novel admixture Centrilit NC for the production of ultra-high strength concrete MC has launched a nano crystallizer. This, compared with silica technology, not only has clear advantages in terms of strength, acid and chemical resistance, but is also the first UHPC-capable concrete admixture based on alumino-silicate which has been given building authority cerification in Europe.
In cooperation with the R&D firm G.tecz based in Kassel/Germany, MC is working on the development of UHPC admixtures. The engineering office founded by Dr. Thomas Teichmann and Dr. Gregor Zimmermann has been working on the optimisation of an ultra-high strength concrete formula for years, the so-called Quantz-Technology. Both directors received their doctorate from Kassel University based on UHPC dissertations and intend to apply their findings in practice. Kassel University is leading in UHPC research and is coordinating a relevant programme for the German Research Organisation. It has received funding to the tune of 9 million Euros and its aim is to assist in making UHPC construction standard practice.
In the search for innovative materials G.tecz came across Centrilit NC and discovered that concretes where this admixture had been added showed exceptional properties, especially in regard to matrix optimisation. G.tecz's experts and experts from MC quickly found common ground for a promising collaboration. To this end the engineering firm tested the effect of Centrilit NC using its own base materials in structurally optimised multi-component systems of the new concrete class UHPC.
Pilot tests on concretes without fibres that had been optimised through specially adjusted packing densities and water film thicknesses, measured bending tensile strengths of over 20N/mm2.
These results could be reproduced and further improved in extensive comparative tests. Based on scientific methods and computer and laboratory assisted methods it enables the Quantz-Technology under inclusion of the solids packing density, the water film thickness and the solids’ particles to unlock performance reserves in the fine fabric system of cement-bound substances and building materials. This way optimal packing density within the cement stone matrix down to nano scale could be achieved.
Based on these successful pilot tests both companies decided to enter into a close cooperation. Together they are developing a new UHPC by pooling their specific knowhow. In addition to Dr. Teichmann and Dr. Zimmermann from G.tecz, Eugen Kleen, Head of Research responsible for mineral building substances and concrete admixtures, is also working on this research project. MC provides materials and procedures, while G.tecz provides modelling and engineering technologies.
The objective of this project is to provide customers, especially those from the pre-cast concrete industry, with the necessary know-how and the materials that are needed to produce ultra-high strength concrete. With the aid of Quantz-Technology cement bound materials that almost have ceramic quality and extremely smooth surfaces will be possible to produce. When using formwork made from glass the concrete even gains a reflective surface. This means that such concretes have the same high density and strength as a ceramically fired material. Since no large scale building elements could hitherto be produced with ceramics, a new UHPC technology from G.tecz and MC would be a first in terms of producing larger building parts with ceramic-like properties.
The global increase in energy consumption necessitates the construction of new and more efficient power plants. In addition to that, against the background of climate change older plants must be adjusted to meet the increase in environmental protection requirements. To this end extensive modernisation and repairs are needed in order to limit C02 emissions and to increase the power plants' efficiency and their environmental "friendliness". MC-Bauchemie has continually developed its material technology with regard to power plants and is playing a part in numerous international large-scale projects because of its specific know how and its extensive product portfolio.
Currently the most outstanding project is the lignite-fired power plant being built in the Polish Belchatow, near Lodz. With a current overall capacity of 4,400 MW it is Europe's largest thermal power plant and is the largest lignite-fired power plant in the world. Construction began in 1975 and six years later the first unit was connected to the grid. The last of a total of twelve units identical in design were completed in 1988. Following Poland's accession to the EU an extensive modernisation programme started in 2005 to fulfil European environmental regulations. First units 1 and 2 were brought up to comply with the latest standard, prolonging their service life until 2016. Since 2007 the remaining units have also been modernised and have another 30 years of service. Following modernisation and the construction of a new 860-MW unit Belchatow will feed just under 4,700 MW of power into the grid. Its high level of efficiency at 42% makes this plant one of the most advanced lignite fired power plants. It will be emitting 10% less carbon dioxide per kilowatt hour than a conventional plant in this region. Start of operation is scheduled for October 2010.
The Polish power plant operators BOT Elektrownia Belchatow S.A. appointed the French specialist construction company Alstom as main contractor and for the start-up of the 900 million Euro project Belchatow II. Together with the principal, German subcontractors, the full range supplier for cooling towers, SPX Cooling Technologies, Ratingen/Germany, and the specialist for fire-proof industrial plants, Karrena, also based in Ratingen, MC-Bauchemie developed the concrete protection system. 48,300 m2 of interior and 12,400 m2 of exterior concrete shell as well as the flue gas raft of the new 180m high cooling tower were coated.
The surface protection system comprised MC-Schutzuberzug 702 for the first and second coats. The interior concrete shell was primed with MC-DUR 1277 WL and was then sealed with two applications of MC-DUR VS NR3. The flue gas raft, which is constantly exposed to exhaust gases, was primed with MC-DUR 1200 VK and then given a coating of MC-FLEX 2099 to act as corrosion protection. MC not only supplied the material, but also trained the applicators. Several times a week Daroslaw Demski, PT chief of MC-Poland and his colleagues were at hand on site. MC has been involved in the modernisation works in Belchatow since 2004 with its specialist expertise. Repair works and coatings were and are still being carried out until 2012 on the reinforced concrete encasement of the two 300m high chimneys, the cooling towers, waste water structures, concrete pipes and water storage containers as well as on coal bridges and industrial floors.
Another current project that makes use of MC's power plant competence is the construction of the new Dutch anthracite coal and biomass power plant at Maasvlakte. Maasvlakte is a man-made island with an industrial area and port, belonging to Rotterdam and situated south of where the river Maas flows into the North Sea. Due to its ideal location (by the water) no cooling towers are required. Construction of the power plant, owned by the energy operator E.ON Benelux, started in 2008. It will have an output of 1,100 MW, which accounts for roughly 7 % of Holland's electricity consumption. The plant, which costs 1.2 billion Euros to build, is expected to be ready for operation during the first half of 2012.
The power plant gains particular sustainability through a 46% efficiency boost and the added possibility of using biomass as well. Furthermore, it has been designed to supply district heat to industry and households in the region. A plant for the capture of C02 and to feed into the pipe network intended to supply garden centres is also planned. In this case the gas is used to promulgate plant growth, because when light and water are sufficient, carbon dioxide concentration determines how much the plants are going to grow. For example, when C02 concentration is doubled, the yield of greenhouse cultures is approximately 40% higher than without such fertilisation.
During the course of the new construction MC admixtures and industrial floor coatings that exhibit long service-lives and high environmental protection (WHG-systems or Water Resources Act systems) will be used. In addition, the top of the chimney where the flue gas escapes, i.e. the so-called down-wash area, is sealed using the surface protection system MC-DUR VS-EW and MC-DUR 2103 M. On the outside the 172m high structure with a surface area of almost 20,000 m2 is receiving the protective coating MC-Schutzuberzug 702. Onsite support was provided by Gerrit Nijenhuis and Thomas Robbe, from the Netherlands CC and PT departments respectively.
Not just abroad but in Germany, too, the demand for replacement capacity is high. By 2020 half of all power plants must be closed due to old age. Hence new construction projects are currently underway in Karlsruhe, Datteln and Hamm where MC is participating. For example, ENBW Energie Baden-Wurttemberg has been constructing an ultramodern hard coal power unit on the site of RDK in Karlsruhe since summer 2008. The new unit (RDK 8) is designed for an output of 912 MW with an increase in efficiency of 46% and is being built to the east of the other seven units. As much as 220 MW of thermal output can be extracted as district heating for feeding into Karlsruhe's district heat grid - depending on heat demand - and operation is planned to commence by the end of 2011. The new chimney will be protected with systems from MC.
In Hamm-Uentrop the energy provider RWE Power is investing 2 billion Euros in building two new double units for the existing power plant in West-falen, near the Datteln-Hamm Canal. The new units D and E on the site adjacent to the disused high temperature reactor THTR-300 are fired with hard coal or petroleum coke and together have a performance capacity of 1,600 MW. At the end of August 2008 German Chancellor Angel Merkel laid the foundation stone for the largest current investment project in Germany.
By mid 2011 the first unit is scheduled to be connected to the district's grid, the second unit by 2012. By then the existing units A and B, which are still designed to use mixed firing supplemented with oil, will have been decommissioned.
The two 165m high cooling towers are built using high-performance concrete for which MC is supplying the admixture Centrilit Fume SX. Because this silica suspension is highly reactive and the particles are 50 to 100 times smaller than cement particles, they fill the cavities in the cement matrix and thus improve the bonding between cement and aggregate. During hydration this leads to a higher density with higher resistance to chemicals and corrosion.
This high-performance concrete is resistant against flue gases funnelled out through cooling towers rather than through a chimney without the need for any additional surface protection.
Concretes used in power plants, e.g. in cooling towers and chimneys, must meet particular requirements. MC has therefore formulated - through adjustments, improvements and new developments - a complete specialist product range consisting of admixtures and coating systems that meet the requirements in terms of acid resistance (>ph 3.5), water-impermeability and resistance to hydrolysis. Fast and reliable repair systems mean less down time and increased plant availability. With its standard range MC can offer contractors a complete package - which is economical, durable and suitable for local conditions.
Furthermore, know-how, competence, service level and local engineering account for MC's exceptional position in the field of power plants. An inter-divisional power plant competence centre, headed by Holger Schwarze and Reinhard Martin support individual country subsidiaries. They organize training of specialist applicators and support their clients in product development and care, in acquisition and participate in national and international expert committees. In addition, conferences are organised such as the "International Symposium Power Generating Industry" at the end of November in Bad Neuenahr/Ahrweiler. Experts and scientists from Germany, the Czech Republic and Poland spoke about the current situation the energy industry is facing, introduced up-to-date technologies and explained their experiences gained in the construction and repair of power plant structures to 80 participants from 15 different countries.
In the area of concrete admixtures MC can boast experience spanning more than 40 years. This is backed up by countless innovative products designed to accurately match the respective application area in concrete technology. This competence of MC also extends to the area of screeds where MC can offer solutions that speed up the construction progress considerably and which increase the reliability of results.
Conventional cement screeds require about six weeks until they can be laid - which hold up the construction progress immensely. Standard accelerators may help to shorten the interval period by 7 to 21 days. However, they have the important disadvantage of greatly reducing installation performance.
Thanks to its competence in the area of concrete admixtures MC's research and development was able to solve this problem and developed an innovative screed accelerator with POWERSCREED 956 that sets new benchmarks in his field. Compared with conventional screed accelerators performance can be bettered by up to 50 %, since it has no noticeable detrimental effect on the screed's consistency and its installation performance.
What's more, when using POWERSCREED 956 the drying time can be controlled and set to 4 to 14 days. Its flow properties that are akin to water enable the exact dosing of the screed mixture; the screed remains easy to be spread and levelled. The result is a homogenous screed with a consistent and smooth surface that can be laid after just a few days.
For some years Brazil has been investing increasingly in improving its public wastewater disposal infrastructure. PAC, the economic stimulus package which part-finances countless projects, has been helpful in this respect since 2007. In Campinas, the second largest city in the federal state of Sao Paulo a large wastewater treatment plant is being built in four phases. It is planned to treat all wastewater produced in the megacity. For this project MC-Bauchemie Brazil supplies not only additives and construction products, but also surface protection, repair and injection systems.
Following fundamental reforms of the state-owned urban hygiene organisations individual federal states in Brazil, amongst them Sao Paulo, have taken measures to strengthen the state-run organisations. The aim is to improve the supply structure by restructuring and opening up to private investors and by partially privatising the operation of local systems. Even today only less than half of all Brazilian households are connected to a sewage network. In total just 20% of all wastewater is treated, even in the more progressive state of Sao Paulo this figure is just 40%. This situation prompted the government to include the sanitation sector in the economic stimulus programme PAC (Programma de Aceleracao do Crescimento) and to provide 40 billion Real (approx. 16.8 billion Euros) for the project initially.
The new treatment plant ETE Capivari I, situated 100 km north of Sao Paulo in Campinas represents the first phase of a four-stage construction project which has been financed with 60 million Real (about 25 million Euros) from the PAC programme. With a capacity of 300m3 per hour the wastewater of 60,000 inhabitants can be treated here. When the last construction phase has been completed Campinas will be the first larger city in the federal state of Sao Paulo that can treat 100% of its wastewater - which will lift the environmental burden on the Capivari River.
At the inauguration of the treatment plant Capivari I, which was attended by the republic's president and its prime minister, mayor Helio de Oliveira Santos stressed that the treatment of sewage was not just showing respect for the environment and implementing sustainability, but was primarily also improving peoples' health and quality of life. While in 2004 only 10% of the wastewater, and three years later 65% of it were treated, the capacity of ETE Capivari I is now able to treat 80%. Construction of the second module is planned for 2010, with the third and fourth building phase to follow in 2012.
By order of the general contractor, a consortium consisting of the construction firm Norberta Odebrecht S.A. and the environmental engineering firm CBPO Engenharia LTDA., MC-Bauchemie Brazil supplied complete solutions in the area of concrete admixtures and surface protection and repair systems during the entire course of the project between October 2007 and March 2009. The concrete needed to be water permeable and have good chemical and mechanical characteristics at a compressive strength of 40 N/mm2.
The best solution, especially for the onsite pre-cast elements, proved to be the synthetic high-tech PCE based admixture, Muraplast FK 65B, which not only improves early strength development, but also offers the possibility to make the concrete more resistant against aggressive media. Combined with the formwork release agents, Ortolan 710 and Ortolan SR, the pre-cast elements could be produced quickly and defect-free. So as to avoid cracks and to give the concrete surfaces better mechanical resistance, Emcoril curing agent was used.
To seal the joints and for the concrete finishing the team from MC, who supported general contractor and applicators throughout the entire construction phase, recommended injection systems and the fibre reinforced repair mortar Zentrifix Gm2. All sealings of the new treatment plant were quickly and safely sealed by applying the elastic injection resins MC-Injekt 2300 NV and MC-Injekt 2033.
To ensure particular leak-tightness of all concrete surfaces subject to exposure to wastewater the highly resistant mineral surface protection system MC-RIM F was used. Coating with MC-RIM F is water-impermeable and yet still allows water-vapour diffusion; it is chloride-proof and resistant to very aggressive waters such as those prevalent in wastewater treatment plants. Furthermore, the system prevents crack and blister formation.
Thanks to its broad product range MC-Bauchemie Brazil was able to offer the customer a complete solution from one source in the construction of the Campinas treatment plant. Construction progress was swift and reliable thanks to MC's comprehensive advice and support. It is expected that MC-Brazil will secure the contract for the supply of the products required for the next stages of this project based on the good experience that plant operator Sanasa and the general contractor consortium have made with MC products and the excellent customer support that the MC team provided throughout.
For a long time the building material concrete did not exactly enjoy a 'creative' reputation that would get architects' creative juices flowing when it came to designing exciting building facades. However, numerous new developments in recent years mean that this has now changed. With modern, ultra-high-performance concretes and novel ideas in the production of pre-cast concrete products aesthetic building facades can now be realised, having the added benefits of saving resources, being cost-effective and durable.
For years, pioneering work in developing procedures for the treatment of concrete surfaces and the production of individual facade elements has been done by Hering Bau in Burbach, Germany. The internationally operating, long-established company, which built its name on rail track and civil engineering, design and manufacture of public toilets and manufacturing pre-cast concrete products, has now filled an interesting niche in the area of architectural concrete. Because these days, architects and developers go a lot more for individual shapes, colours and surfaces when selecting the design of a facade.
Hering Bau knows all there is to know about surface treatment and the different methods to make the stone inside the concrete visible and treats concrete formwork as an art form. "Individually made formwork, frequently in the form of one unique piece with very few copies or even no copy at all, plus the various possibilities to work the surface, give architects a new level of artistic freedom", explains Gunter Haas, Production Manager. In addition to the production of formwork-smooth surfaces, a diverse range of processing methods, such as sanding, acid-solution treatment, washing, sand-blasting, relief-technique and the specially developed 'photo-imaging on concrete-technology' or a combination of these different methods, are being put to use.
Rather creative is the design of the Protestant Community Centre in Mannheim, Germany. The facade is made of recessed glass elements with smoothly formed, gleaming white pre-cast concrete elements. The architect's specification to show moving grass blades made for a demanding process in terms of appearance and manufacturing technology. Equally unusual is the use of template formwork technology as in the case of the elephant house in the Cologne zoo. Here the facade's surface structure has been made so as to resemble the roughness and colour of elephant skin. Another interesting example is the use of relief concrete as used in the design of a pedestal for an administrative building in Essen which shows the binary code, creating a perfect contrast to the strict glass facade.
With betoShell® Hering Bau also produces curtain facade panels for new buildings and to repair existing buildings. These are made from ultra-high performance concrete with an innovative glass fibre cladding which was developed in cooperation with the Technical University in Dresden. The panels with DIBt approval measure 1,200 x 600mm and are just 20mm deep, making them real lightweights, which saves material and is extremely eco-friendly. What's more, they can be fitted without the need for a tower crane. The textile reinforcement and the specially developed concrete formula give them enormous tensile strength. This could be significantly strengthened further still by using the new admixture Centrilit NC from MC-Bauchemie. The tensile strength is now double that of concrete steel reinforcement. Furthermore, betoShell® facade elements have an exceptionally high bending strength that is resistant to the highest stresses with regards to wind load and frost. The company is now able to produce elements up to 12m2 in size thanks to joint developments with the Institute for Solid Construction of the RWTH Aachen.
"On top of the aforementioned, the white admixture Centrilit NC proved to be the optimal solution for the colour design of our facade panels", emphasises lab manager Ulrich Hilbert. Admixtures that were used prior to Centrilit NC only produced a limited colour range despite the use of white cement. Another, particularly eye-catching method is photographic concrete, whereby photographic and realistic images and art reproductions are superimposed onto the facade panels, which may even have a kind of 3D-effect. An example of image subject matter matched to the building purpose can be seen on the facade of the Marienkrankenhaus in Hamburg (hospital), which shows a Madonna and Child.
Many other reference projects in Germany, the Netherlands and in Great Britain, which range from concert halls to shopping malls, memorials, zoos and public buildings, are testimony to the creativity, quality and vast range of uses of architectural concrete -which has just become even more versatile through the application of Centrilit NC. The most current example is the construction of the Community College in the Dutch town of Leiden, where the college and its office buildings are currently receiving a curtain wall facade measuring 9,500m2 in total made from 30mm strong individually produced betoShell® elements.
The international energy sector is facing enormous challenges: on one hand modernisation and expansion of electricity generation must go ahead in order to be able to meet growing global demand. On the other hand, due consideration must be paid to environmental aspects in order to reduce C02 emissions in accordance with international agreements. The coming years will therefore see the necessity to build new power plants, and the need to renew and modernise existing plants - and the latter is on a much larger scale. For over 40 years MC-Bauchemie has acquired a reputation in the energy sector for supplying quality products and systems especially for surface protection products.
In close dialogue with planners and operators of power plants MC specialists have developed protection and repair systems based on the various problem scenarios encountered in international projects. This is one of the reasons that MC is a technology leader in the protection of concrete structures.
With commitment and experience MC developed concepts that provide plant operators across the world with a complete product range. MC has special concrete admixtures and additives to produce concretes with increased acid resistance to after-treatment and coating systems that offer long term protection. This enables the energy sector to maintain output and operational security of their plants. This in turn ensures reliable electricity and gas supply to private, industrial and commercial consumers.
Coating technologies are used primarily in cooling towers, chimneys, reactor domes, cooling-down stations for castor containers and other decontaminable areas, as well as in transformer bunds, gas condensing stations and LNG (liquified natural gas) tanks. Injection technology is used to seal masonry in dams and in water inlet and outlet basins. Repair products are applied in all kinds of concrete structures, for example, in silos. Added to the above are industrial floor coatings for turbine halls and other operational buildings. Quality specialised admixtures ensure the safe production of high-performance concrete, which can be designed to be impermeable to water and have a high degree of acid-resistance if required.
MC continually adapts its own Research & Development to the current requirements of energy and construction industries. The new admixture Centrilit NC, for example, offers customers a vastly improved application spectrum.
As Dipi.-Min. Eugen Kleen, Head of Development of Mineral Construction Materials and Concrete Admixtures, explains, MC has been able to make the step to the use of semi-synthetic base materials. This means the secure and continuous supply of raw materials. "Research and development that is continuously matched to suit the application requirements also enables the optimal function of surface protection on structures of power plants, which are incoherently subject to enormous stress,” says Dr. Peer Heine, Product for Manager for Resin-based Industrial Flooring and Power Plant Coating Systems.
In close cooperation with the faculty for Building Material Research at Dortmund University, the Material Testing institute in Berlin and specialised engineering firms, ongoing progress is made in this area that is of benefit to the energy sector.
MC has been steadily developing technologies for the planning, construction, protection and repair of cooling towers. Products for the long-term protection of both interior and exterior walls have been developed. They have arrange of properties such as moisture-compatibility, water-vapour diffusivity and chemical resistance. Such technology has quickly become accepted as an industry standard and has become the declared norm in the repair guidelines of the German Association for Reinforced Concrete (Daf-Stb).
With the integration of flue gas desulphurisation plants (FGDS) in the coal burning process, the concrete shells of cooling towers need to be protected against the effects of sulphur-dioxide, which condenses on the surface as aggressive acid. For this area MC has developed a special, thick surface protection material, which has become another established technology standard, enshrined in the CGB guideline “Structural Design of Cooling Towers”. High-performance concretes are also used when new cooling towers are built, which are made resistant to such acid attacks by incorporating Centrilit NC or Centrilit Fume SX which eliminates the need for additional surface protection. Despite this, surface protection is still required in repairs as well as for repair systems that have been specially designed for that purpose.
In repairs the substrate is first treated using high pressure water blasting. Exposed reinforcement steel is coated with a mineral based corrosion protection system. The reprofiling and patch repair is carried out using the polymer modified mortar Nafufill KM 250. The final step is, as always, surface protection with long term effect. The objective here is to achieve a technically safe usage of the cooling towers that matches the service life of the power plant.
Dr. Peer Heine comments on the role of VGB Power Tech: The association of large power plant operators is a registered organisation that provides a range of different services for its members, such as coordinating research activities, neutral discussion forums for all members, technology advice, structural and damage analysis, publication of information and HR training, The VGB has several power plant simulators for training purposes. The current technology standard for power plant construction and operation is documented in a number of guidelines, published by the VGB.
Equally high demands are made on reinforced concrete chimneys and reactor domes in nuclear power plants. Chimneys are exposed to aggressive flue gas concentrations that attack the concrete surface – especially at smoke exit points. Add to that extreme, occasionally sudden changes in temperature, coupled with wind pressures, and the result is heavy loading on the structural elements. To ensure a lasting service life chimney shafts must be protected from penetration by harmful air and water borne chemicals.
Coating systems such as the MC-DUR range seal the down-wash area and combined with MC-Schutzuberzug (protection cover), ensure the long-term protection of reinforced concrete structures under such extreme conditions. This protection is valid in both construction and in repair phases. MC offers the possibility of creating aesthetically pleasing designs by providing protection systems with high UV stability and project-specific colours.
Reactor domes made from reinforce concrete several metres thick are required to ensure the safety of nuclear power plants. Additional shear reinforcement protects the reactors from external impact.
MC high-performance surface protection systems have an anti-carbonation effect and secure the durability of these specialist structures. There is always a danger of crack formation in the very high concrete cover of reactor domes, so that crack-bridging coatings must be used.
Furthermore, the surface protection gives effective colour stability. This is especially important as the domes, because of their shape are always completely exposed to the elements and are always highly visible to the public.
The special know-how and the competence of MC-Bauchemie in a consultancy role have made the company an important partner for the energy industry with regard to achieving reliable long-term protection of energy plants. Under the management of Holger Schwarze and Reinhard Martin a multi diversional team of experts support operators, planners and contractors all over the world imparting and applying their expertise to large scale projects.
The reference list of plants receiving MC support and products is long, including for example China, Russia, several Arab States, Eastern and Central Europe countries, Brazil and Chile. China is recording the greatest growth in investment in the energy sector. Its development of energy supply has not been able to keep pace with the country’s rapid economic rise.
Central and eastern European countries are also investing heavily in the modernisation of their energy industries, assisted by funding from the European Union. MC has been involved in repair and new construction projects in Bulgaria, Poland, Romania, the Czech Republic and Hungary. In Poland along 120m high chimneys in the Rybnik and Skawina power plants were recently coated with MC surface protection systems along with a couple of smaller chimneys in the Skawina plant.
One of the most important criteria in the new building and the renovation of sewers is the durability of the entire system, which should ideally last over 100 years. However, the concrete types, which are generally used in sewers, exhibit shortcomings in terms of acid resistance. To this end, MC-Bauchemie has developed a materiel based on Centrilit NC an admixture which provides the concrete with increased acid resistance.
The advantages of concrete in the construction of sewer systems have been known since the construction of the Roman Cloaca Maxima in about 300 BC. The first reinforced concrete sewers were built in Europe over 2000 years later. Today, over 90% of sewers are constructed of concrete. They can withstand the structural demands imposed by ground conditions, groundwater level and traffic loads. Internal stresses due to flow rates and abrasive particulate matter can also be withstood. But problems can arise due to corrosion, which can be triggered by aggressive sewage and biogenic sulphuric acid attack in the gas zone of the pipe systems. Although alternative materials such as GRP, HDPE, PVC and polymer concrete do perform better on this point of chemical resistance, high loadbearing properties cannot be economically produced and, consequently, are no real alternatives to pipes and chambers made from reinforced concrete.
The efforts of the industry, science and technology have, to date, focused on minimising the weaknesses of concrete. These efforts have been successful largely due to the research and development work of MC-Bauchemie in cooperation with Prof. Dr. lng. Bernd Hillemeier. The ground breaking issues in these fields included the development of SRB-concrete, a composition which exhibits an increased resistance to acid and which was used for the first time 10 years ago in the construction ofpower staton cooling towers (Niederaubem). At that point, the aim was to manufacture a concrete, which was permanently resistant to a value as low as pH3.5. This was achieved, primarily, through an optimised particle packing density and the combination of concrete additives, admixtures and minimisation of the cement content. Since then, it has become the best available technology in this SRB sector.
Another important improvement is promised by the introduction of the innovative Centrilit NC, which is based on alumosilicates. The basic element is a thermally treated sheet silicate. This thermal treatment changes the silicate's properties in such a way that it acts as a latent-hydraulic or pozolanic material. The sheet silicates used by MC are natural materials, occurring in the Earth’s crust, of which there is virtually an unlimited supply and whose properties can be specifically modified.
These alumosilicates are materials which contain gravel and clay. Compared to silica fume which has been used in high performance concretes (HPC) up to now and is actually only available as an industrial buy-product, alumosilicates do not form a gel in the alkaline pore solution of the cement matrix. Instead, they act as crystal nuclei in the finest pores. On a nano scale, the disc structure creates a reinforcement which can be terms as crystalline microstructure or nanocrystallisation. With these properties, it is possible to create a concrete, which exhibits an extremely high structural density and with virtually no pores.
While normal concrete usually has a capillary pore volume of 15 Vol.-%, UHPC (Ultra High Performance Concrete) can be produced with a pore volume of just vol. 1.5 to 1.8 Vol.-%. As a result, there is not only higher stability, UHPCs more effectively resist the forces imposed and are, consequently practically impermeable to liquids, gases and chlorides.
In 2008, using comparative test in which the Niederaubem concrete mix design (SRB) acted as reference material, it is determined for the first time that the acid resistance can be considerably increased by adding Centrilit NC. In the meantime, the development department and applications engineering division of MC-Bauchemie now has the necessary knowledge to modify existing mix designs for customers. With a relatively small effort, mix designs can be modified to achieve and have officially verified increased acid resistance.
However, the limits of concrete technology are far from exhausted! As part of a quality offensive, the MC research department is on the way to developing a cement based substance, with which it will be possible to create sewer systems which not only have all the benefits of UHPCs with the added acid resistance of ceramics. The durability achieved with such concrete components in the sewage plants and sewer networks leads to high cost savings due to considerably extended maintenance intervals. This innovation is made possible by the use of Centrilit NC, which is increasingly being used in special situations to achieve high performance properties.
The worldwide success of ready mixed concrete (rmc) began with the development of the modern truck mixer. From 1954 thousands of ready mixed concrete plants emerged in Europe. This was just one sign of the massive growth and increase in activity in the construction industry. By 1971 ready mixed concrete accounted for almost every 50% of all concrete produced in Europe. The development of complex and advanced admixture technology for concrete and mortars also contributed to the rapid growth of the rmc business. Since the 1960s, these materials have been the main focus for MC-Bauchemie.
The growing influence of the rmc industry highlighted questions about the quality of the concrete delivered on site. Previously only a mixture of sand, cement, aggregate and water was needed to provide high quality concrete on site. Extra water, above that in the concrete specification or in the mix design, was added on site to make the concrete easier to place and compact by the work force. But the strength and durability of the hardened concrete is adversely affected by the addition of too much water. MC therefore developed the Centrament range of high performance plasticisers that increased concrete workability without the need to add extra water. This launch of these materials coincided with the emergence of standards for the various types and uses of cement.
In its pioneering role, MC, in addition to continuous product development also developed and continues to do so innovative technology for concrete and the admixtures it contains. With growing admixture demand and more sophisticated technical challenges for the concrete producer, it soon became apparent that it was no longer sufficient to limit admixture performance to the extension of workability time. To ensure the concrete could still be transported, pumped and compacted over ever increasing distances and time, plasticisers such as Muraplast were developed by MC.
After the introduction of European standards in the late 1990s, the specified water-cement ratio was lowered further by the introduction of ‘exposure classes': One of the drivers behind this development in the European standards was the increase in innovative construction methods and the use of thinner sections in beams and columns. Hence the fresh concrete had to have a higher workability and high final strength.
The architectural trend for increasingly tall and filigree structuring led to the development of admixtures based on polycarboxylate ether (PCE). This new generation of plasticiser known as MC-PowerFlow, achieves a highly workable, flowable concrete with self-compacting, high performance properties. MC was the first manufacturer of admixtures to obtain a general certificate of approval from the German authorities. MC therefore set the standard. The admixture maintains concrete workability enabling rmc to be delivered, placed and compacted over extended periods of time.
MC has now introduced MC-TechniFlow a cost effective range especially for use in CEM 11/M cements that are increasingly being used in the ready mixed concrete sector. Thanks to its innovative formulation it can be used in conjunction with a wide range of cements and aggregates.
With this broad selection of products, which are specifically aligned with the needs of the ready mixed concrete industry,
MC has a leading position in the concrete and mortar admixtures field. MC's research department played a major role in this achievement and concrete producers worldwide appreciate not only the product innovations but also MC's competent technical support. International presence
MC justifiably claim to meet the 'just in time' requirements of the rmc industry and offer an advisory support service irrespective of time and location. It is achieved by an extensive sales network in close contact with customers, and production locations and service centres in 40 different locations in 30 countries. Thanks to in-house chemists, concrete technologists and application technicians in the various national affiliate companies, MC is in a position to adapt to the regional cements, so that the concrete is exactly as it should be for the location where it is used.
The Commerzbank tower and neighbouring Main tower are prime examples of the use of modern high-performance admixtures in Germany. These buildings are distinctive features of the Frankfurt skyline. For these structures, the concrete had to be pumped to a height of 200m. For the RWE natural draught cooling towers in Niederaula and Neurath the concrete also had to be pump-ready to this height. High-tech products such as Muraplast FK and Centrilit Fume were also used. The additional acid resistance of the pumpable concrete was an especially important factor. Other reference projects are the Potsdamer Platz in Berlin, the biggest domestic project to date, or the expansion of the airports in Stuttgart, Leipzig and Frankfurt. In Germany, the service centres in Bottrop, Hamburg, Berlin, Munich, Leipzig, Frankfurt and Esslingen use the wide spectrum of MC services in practice.
MC has had its own production plants in Ireland since the beginning of the 1980s and supplies the largest ready mixed concrete suppliers in the country. The Irish affiliate played a leading role in the introduction of PCE admixtures. There has also been a production plant in Hungary for some 20 years, from where MC supplies the rmc market leaders in admixtures. Due to their extensive expertise in the field of PCEs, MC occupies an impressive place in the market. In the Netherlands, this technology is a good match for Dutch cements. It is not surprising that MC supplies the largest Dutch ready mixed concrete manufacturer. In France, it is mainly the southern part of the country that is served by the production plant south of Lyon. In Portugal, MC admixtures are used for dam and other large projects. Our own laboratory supports the ready mixed concrete companies.
In Spain, the annual demand for ready mixed concrete is approximately 37 million m3 MC admixtures - in particular, PCE-based products - are being used for port and other public works projects. Expansion projects at the ports of Lanzarote, Mallorca, Barcelona, Valencia, Cadiz and Bilbao were completed using MC-PowerFlow 2210. The same admixture is currently being used for the Ute Obra de Abrigo project in the port of Valencia as well as the Algerian port, Cajones Arzew. MC-PowerFlow 2250 ensures optimisation of concrete properties and is used in the construction of the Ossa power plant for the energy company lberdrola. Other projects are planned at the ports of Barcelona, Mallorca, Tenerife and La Coruna. For these projects, especially high demands are made of the concrete quality, so that only PCE-based admixtures can be used. Nevertheless, in Spain many of the about 2,000 rmc plants are not yet using admixtures, not to mention PCE technology. MC offers support mainly to medium sized business partners by providing solutions and offering training courses to advance the conversion to modern, more cost effective concretes.
In the Czech Republic, the company is especially active in motorway construction. There is not a single motorway here that has not been built using MC admixtures. Only last year, the motorway bypass around Prague was finished, it has total length of 25km and two tunnels. The repair of the old concrete motorway between the capital city and Brno will be carried out in the near future. The highly modern production plants and the extensive laboratory have become prototypes for the construction of new MC production plants. MC is also present in the Slovakian ready mixed concrete industry. Deliveries come from the Czech locations.
In Poland, MC_Bauchemie is one of the market leaders for the concrete admixtures. Since 1994, business here has continuously expanded. MC was also the first international manufacturer of admixtures to set up a production site with a laboratory in Poland. Three service centres in Warsaw, Wroclaw and at the production site in Sroda Wielkopolsks offer advice and support to partners in the ready mixed concrete industry.
An additional two sites are planned to strengthen the national organisation. In addition to projects already completed such as the A1 and A4 motorways as well as various projects in Warsaw including bridges, underground stations, skyscrapers and the airport, a bridge in Kwidzyn is currently being built using MC admixtures. A further section of the A1 and A2 motorways is planned as well as a power plant at Opole.
MC has been producing concrete admixtures in Russia, which are delivered to the rmc industry from four locations, for about 10 years. An in-house laboratory supplies the special formulae for concrete and mortar admixtures. More than 40 employees are active in the Construction Chemicals division in Russia. The Ukrainian cement also puts its trust in admixtures from MC. These are currently being used in a number of airport projects.
Serbia still has no admixture manufacturers and about 500 ready mixed concrete plants rely on imports. MC will also be a pioneer here. At Sremska Mitrovica a new production site is due to be built.
The Brazilian ready mixed concrete industry is booming thanks to high demand for construction materials in the infrastructure sector. For example, MC admixtures are being used in the energy sector for the construction of the new hydro-electric power plant at Jirau at Rio Madeira. This dam worth about 3.7 billion euro is provisionally planned to start operation in autumn 2016 and will produce 3,300MW of electricity from 44 turbines. MC-Bauchemie offered intensive technical support, constant backup from the R&D department as well as excellent results in the trial mix phase and succeeded in winning the Brazil project against strong competitors. Initially, in addition to the air entraining admixture Centrment Air 202 and retarder Centrament Retard 352, the plasticiser Muraplast FK 100B was supplied. During the construction phase, the general contractor Camargo Correa, which is carrying out the project with the French construction company GDF Suez, asked for PCE-based admixture. MC-Power-Flow was used after passing the tests. The dam project now only uses only this new generation plasticiser. In addition to optimisation of concrete properties, the construction company highly values the improved cost-effectiveness. As the impact of MC-PowerFlow is much stonger and a lower dosage is required than Muraplast, the transport costs are reduced. A single tanker takes six days to reach the construction site from the production plant near Sao Paulo and this trip alone costs about 7,000 euros.
In Taiwan the ready mixed concrete industry is influenced mainly by medium sized businesses. Only five large companies are active countrywide. Major projects recently completed by MC Taiwan were the construction of a high-speed rail link as well as Motorway 1. Since last year, admixtures are being delivered for the new China Dragon steel works and several extensive maintenance projects are planned for rail links in the metropolitan area of Tachung. The first tender was awarded in October with a further two following in May and June. PCE admixtures for self-consolidating concrete are mainly used in Taiwan, MC Taiwan supports the ready mixed concrete plants mainly with test mixes and quality control at the construction site. The national affiliate company also works with reputable ready mixed concrete works in the marketing division and offers their clients consultancy serves. Even in Malaysia, MC-Bauchemie supports the local ready mixed concrete industry with its own admixture production site.
In 2011, the production of raw materials in Bottrop a technically complex polymerisation site for the manufacture of basic resources and raw materials for innovative PCE products will be extended. This increases flexibility in production and the availability of basic resources and raw materials necessary for the manufacture of PCEs.
The new generation of cement based screed Estrifan ECE 2015 means shorter drying times by up to 33 days! At the same time, the daily production rate can be increased five-fold in comparison to conventional screeds. This super-fast system is currently being introduced to the market and also presented to applicators in a series of seminars.
In architectural drawing, screed is only a line, but in practical terms this floor is the layer that has to be highly resilient in every building. Due to its application technology, conventional cement screed does not always meet today's quality requirements. This type of screed is sometimes poorly consolidated with the result that this building part, which is usually under high pressure, is susceptible to damage such as cracks and local de-bonding. This means that the requirements for compression and bending tensile strength specified under DIN EN 13813 cannot always be easily met. And as a priming system, screed has a tendency to exhibit rewetting due to subsequent construction activities. Finally, the long periods required for drying of between four and six weeks restrict progress on the building site because not only the readiness is dependent on this, but also it restricts others' access to the room to carry out any work. Then there is the complex and tiring work involved in the installation: a three-man team generally cannot finish more than 120m2 per day.
The anhydrite screed, which is easy to apply, with laying capacities of up to 1,500m2 and involving a three-man team is also highly sensitive to damp conditions. To prevent mould formation, the surfaces also have to be rubbed down. In addition, a relatively long drying period of three to four weeks is also required.
The new screed generation Estrifan ECE 2015 developed by MC is the solution for the fast and safe manufacture of screed floors. This cement poured concrete system with a compressive strength of CT 20 and tensile strength F4 exactly meets the standards, but is differentiated from other types of screed by its modified laying characteristics.
Here, high laying capacity is combined with fast curing. A two-man team is capable of achieving about 1,000m2 per day without undue operative stress and physical strain. The floor can be accessed after 1 - 2 days. After 5 – 7 days it is ready to be sealed and covered after 7 - 9 days. The key to the product qualities is, on the one hand, the special composition of the matrix and on the other the special plasticiser. The matrix consists of binders and graded sands, and the plasticiser can be provided with a protective coating. The control of the raw materials ensure good levelling and compaction, a high laying capacity and short drying time. This means the results on site are better and the drying time is faster.
The screed is pumped into the building and then evenly spread. Levelling blocks mark the required height. Finally, the material is trowel led in two stages, lengthwise and from side to side, thus evenly distributing the screed. There are no problems with unevenness or shrinkage. Re-working of the surface is no longer necessary either. If a rapid access is required, the screed is simply sealed. Thanks to the easy application, the higher laying performance is achieved and also a better workload from the team laying the screed.
Estrifan ECE 2015 is suitable as a floating screed or a screed on a separating layer for nearly all top surfaces. It can even be used in cellars, garages and wet rooms. Due to its viscosity, it is especially suitable for the installation of underfloor heating. The material, optimising the heat transfer, tightly surrounds every heating loop.
The controlled production in ready mixed concrete or other mobile mixing units offers a high degree of reliability regarding results and punctuality for every project. With ready mixed concrete, the zero consistency, that means the spread value of 45 - 50cm. The truck mixer carries the plasticiser which is mixed in on site at a ratio of 2 - 2.5 l/m3
MC also cooperates with the company Brinkmann, the leading specialists for screed machines, with the mobile screed logistic system TransMix in their product program. This mobile transport, mix and pumping unit delivers all of the raw materials to the building site. A tray with two or three chambers for the screed components is mounted on a lorry 4 axle chassis or on a semi-trailer. The rear is equipped with a mixing container and a spiral pump.
After the suitability test, the required recipe is programmed into the control unit; the consistency is determined using the plasticiser. 22-25cm are enough for the expansion level. The computer doses the components fully automatically into the mixing container. Binder, water, aggregate and plasticiser are mixed and the screed is pumped to the point of use. With the help of a remote control device, the screed installer can regulate the water content and adjust the pump speed. Unused raw materials remain in the chambers for the next assignment.
Together with Estrifan ECE 2015, this innovative system offers the applicator a way of making their work much easier and a perfect production of quality high-grade screed coverings.
A completely new high performance super plasticizer revolutionizes the manufacture of precast concrete elements: With MC-PowerFlow 3100 precast element plants manage not only with less water and expenditure for condensing and follow-up processing, they can also produce quicker.
The new super polymer was developed by a research team around the holder of the Science Medal of the German Construction Chemical Industry, Dr. Mirko Gruber, and is based on the innovative architecture of a polycarboxylate estercomb polymer. The aim was to reach a high plastification of the concrete over a relatively short time of 30 to 60 minutes. Afterwards a very rapid strength development should follow without stickiness. This has been achieved in all respects with MC-PowerFlow 3100. The new high performance superplasticizer thus represents a giant technology leap in the development of PCEs.
By fast adsorption on the binding agent surfaces the liquefaction effect of the robust superplasticizer used in the application sets in as soon as it is added to the mixture. This saves water considerably and shortens the mixing time significantly. Because of the strong interaction with the surfaces the concrete gets particularly light flow behaviour - even in the case of high grade of reinforcement of the precast elements.
The highly effective surface coating ensures stable, non-separating consistency behaviour within the first hour. In the case of unchanged water content a consistency extension can be reached through several consistency steps. The concrete can also be pumped more easily and condensed with less expenditure of energy than before. In addition, the product's use leads to an optimized smoothing behaviour of the concrete. A light, smooth layer of so called paste forms on the surface, a water-/cement mixture that does not have to be further processed. Good exposed concrete surfaces are thus possible straightaway. Because little water is used, there is also no risk of efflorescence.
As the polymer has no influence on the hydration, a rapid strength development with a very high early strength begins after the consistency phase. The required strength of 17 N/mm2 is reached after eight hours already, so that the element can be de-moulded. Through the continued very speedy strength development, the elements have already reached their required crushing strength after seven days instead of the usual 28 days and can be delivered.
The economic advantages for the precast element plants that use MC-PowerFlow 3100 are evident: due to the high robustness of the superplasticizer fluctuations in the water-/cement equivalent do not have any effect despite constant low dosage. The standard recipe can also be used for critical elements. This reduces the number of recipes needed in the plant, leads to a better calculation of the aggregates and ensures greater effectiveness when ordering and storing.
The rapid plastification economises water and the short mixing times of under a minute enable the production of larger amounts of concrete at the same time. Good flow behaviour and low viscosity ensure a speedy product ion run. Less energy and time is needed for the jolters during thickening. Less labour is needed for follow- up processing due to the particularly smooth surfaces formed. The very rapid early strength development enables the precast element plant to work two shifts within 24 hours for the first time without the use of a catalyst and so produce double the number of elements. Four hours are calculated here for the mounting and dismantling of the form work and reinforcement respectively as well as eight hours for the hydration react ion with only two hours heat treatment. The saving in energy for shorter or less intensive heat treatment has a decisive effect on the production costs at constantly increasing energy prices.
The laboratory test results with MC-PowerFlow 3100 were confirmed in a large-scale test series with a total of 90 trials in different precast element plants with varying raw materials and partly even surpassed: in the largest Polish precast element plant the strength values required for dismantling the formwork were even reached without heat treatment - and that was at outside temperatures of 1oºC during the daytime and 0°C at night. Previously the elements were heated up to 60°C with heavy energy expenditure, in order to obtain the required strength quicker. The use of the innovative superplasticizer in the case of earth-moist concretes, such as pipes and ducts was also able to be substantiated impressively.
Even in countries where the aggregates often show a higher level of contamination, it was possible thanks to the robustness of MCPowerFiow3100 to manufacture even ultra high performance concrete. In Romania the concrete reached extremely high initial strengths despite irregular cement quality, which were already at 45N/mm2 after one day. Similar results were able to be observed during the tests in Serbia, where the required final strength of the concrete was already attained after 20 hours again with strongly fluctuating cement rating.
The tests carried out under very different basic conditions prove impressively that MC-Bauchemie has succeeded in developing a superplasticizer especially for the precast element industry, with a new path in the polycarboxylate ether technology that releases an important saving potential with its product characteristics and sets new standards in the trade.
In February 2014 the town of Sochi on the Black Sea coast will host the XXII Olympic Winter Games in Russia. All competition venues are being built from scratch and the mammoth project is already in full swing. According to the Olympic motto "Citius, Altius, Fortius" ("Faster, Higher, Stronger") products of MC-Bauchemie are also being used in some sports arenas and in the Olympic village.
The "Sports Festival" in Sochi and its trouble-free presentation is considered to be a challenging prestige project. That is why completion of the currently largest construction site in Europe, within the stipulated time schedule, has top priority. An indication of its importance is the fact that the Russian government is investing around 12 billion US-dollars. These are the first Winter Games in a subtropical town that, despite its geographical location, offers good winter sports conditions especially at the mountain sites from the middle of January. There are two centres for the 92 planned competitions. All the indoor competitions will be held in the five ice stadiums of the centrally situated Olympic park and the Olympia stadium of the city with 340,000 inhabitants, which has room for 40,000 spectators. The skiing, bob sleigh and tobogganing competitions will take place in Krasnaja Poljana, about 60 km away. A good two years before the start of the games, the Sochi 2014 Olympic Organizing Committee (SOOC) has its hands full coordinating the various construction projects and hurrying the completion along. It not only concerns the competition venues, but also the Olympic village, streets, bridges and tunnels. Two thirds of the budget is being invested in the infrastructure alone. In cooperation with the contractor and ready mixed concrete supplier Nospovik MC has delivered products for the ice stadiums, the Olympic village, the bob run and some tunnels that are still under construction. The ready-mixed concrete for example often has to be brought in over long distances and on poorly developed roads. The high performance super plasticizer MC-Power Flow ensures that the concrete arrives on site without loss of workability even after many hours travelling in the truck mixer. This is particularly important in the case of tunnel construction, where the concrete is used in wet-mix shotcrete. However the new bob run was a very special challenge. It was designed by the engineering office of Gurgel +Partner from Leipzig, a designated specialist in this field. The bob run consists of concrete columns, on which rests a metal frame made of many rods, with cooling pipes running inside them. The contractor was instructed to encase the frame with concrete using the dry shotcrete process, which is unusual for such purposes. The contract for the material supply was awarded to MC Russia in the face of strong international competition. As there was no suitable existing mortar for this very special application, MC-project manager llya Bukin had to develop, along with the Russian mortar manufacturer, a completely new product, which was named MC-Gun. It has excellent spray characteristics, can be applied without any problem and adheres well to the substrate. These features are particularly important, as no cracks were allowed and the areas between different applications had to be seamless. After roughly two months formulation development and a test phase lasting another month, MC-Gun passed all the tests conducted over a one week trial in the Swiss Hagerbach test gallery. After finalising the formulation, MC Russia personnel were present at all stages of the project up to the approval by the national Olympic committee. The 1 ,814 m long bob sleigh run was officially opened in March had passed all the safety tests with flying colours at the beginning of the year and also met with great enthusiasm by the athletes in the first test runs.
Tunnels play an important role in today's transport infrastructure. Making sure that they are built to last is a major engineering challenge, with huge demands being placed on such undertakings due to the stresses and loads to which such structures are subjected. The concrete technology applied in these mammoth projects has significantly changed over the years. Yet the complexities involved continue to grow, which means concrete technology from MC remains in high demand across the world.
Traffic volumes are exploding, particularly in the major metropolises of Asia, the Middle East and South America. The density of urban development means that aboveground modifications to inner city infrastructures are rarely possible. Consequently, planners are turning to the subterranean world, placing ever more emphasis on the construction of tunnels. Underground railways - "metros" - are currently being built in ten of India's biggest cities. And major sewerage systems are being increasingly built underground. This is the case with the ongoing Emscher project in Germany (as reported in MC aktiv 3/2012) and the huge STEP project in Abu Dhabi, UAE.
Many different geological influences and stresses have to be taken into account when contemplating tunnel construction. As a result of the pressures brought to bear by rock, earth and/or water, tunnels have to exhibit huge load-bearing capacities, be leak-proof and remain resilient and chemically resistant for a period of at least 100 years- the timescale usually specified as their useful life. There are various processes for tunnel construction, one of which involves progressive lining with tubbings (tubular segments), a method that has been widely applied in recent years in many a major project.
In recent years, particularly, mechanical tunnel heading using the tubbing method has undergone something of a revolution. Previously, the very high strength of the tubbings rendered them brittle, and therefore- particularly with the high pressures applied by the tunnel boring machine highly susceptible to cracking and spalling. Today, however, concrete mixes reinforced with steel fibres are used, rendering the concrete significantly more ductile. This both reduces the incidence of cracking and significantly increases load-bearing capacity. The cracks that do occur are very small - less than 0.1 mm- and heal themselves in the course of time. The addition of plastic fibres in the concrete mix also increases the fire resistance of the structure. The joints between the individual tubbings are sealed by means of sophisticated frame gaskets. Effective and efficient tunnel construction by this method relies on the tubbings themselves being accurately manufactured to ensure a perfect fit as they are positioned. Consequently, the finished components are produced with dimensional accuracies down to a tenth of a millimetre. The formwork moulds are placed on elastomer bearings and then gradually filled with concrete, with periodic compaction being carried out by means of external vibrators.
In addition to the requirements specified by the planning engineers, local conditions also give rise to major challenges in tunnel construction: aside from flexural tensile strength and post-cracking behaviour, high demands are placed on durability criteria such as resistance to chloride diffusion or sulphate attack. The tunnel must be able to withstand all kinds of aggressive media for a minimum period of 100 years. Further requirements on the part of the specifiers relate more to cost-efficiency in manufacture: the consistency of the concrete must al low rapid formwork stripping, and the compaction process should ideally be carried out with as little vibration energy as possible in order to avoid accelerated fatigue in the expensive formwork moulds. These need to stay intact so that they can be reused for numerous filling cycles.
The additives used likewise need to guarantee the required reactions and concrete consistency, often under difficult conditions. In hot countries there is often a problem in adhering to the maximum permissible fresh concrete temperature. In such cases, ice, for instance, may be added to the concrete formulation. Further challenges include the cements and the quality of the aggregates. In the Middle East and Southeast Asia, for example, good quality sands are often hard to come by, with work therefore frequently being carried out with crushed sand. These conditions make concrete production for tubbing manufacture more complex, which in turns means that extensive concrete technology expertise is necessary in order to find a suitable formulation. "We do not provide our clients with off-the peg solutions. Rather, we develop the right formulation in interdisciplinary teams with other partners in line with the requirements of the construction project," explains Eugen Kleen, a globe-trotting concrete technologist and laboratory manager at MC-Bauchemie. "We also take into account the local conditions and raw materials, carrying out tests until together we find the optimum mix. We then have this analysed and tested by independent laboratories. Thus we provide our clients with a verified, viable, individually developed, integrated concept with which they are able to save time, effort and, of course, a great deal of money”.
Major project in Abu Dhabi The Strategic Tunnel Expansion Programme (STEP) in Abu Dhabi is one of the most extensive infrastructure mega projects of the Gulf region. The coming years will see the construction of84 km of tunnels there for expansion of the sewerage network alone. A newly planned sewage treatment plant 42 km east of the city is to be connected by a new main collector, the "Deep Tunnel Sewer': to the sewerage system serving urban Abu Dhabi. The conditions in the desert that forms part of the Emirate are extreme, with temperatures of over 50°C, a highly saline environment and significant humidity. Herrenknecht, a world-leading technology developer in mechanical tunnel heading, has supplied not only 14 tunnel boring machines but also 162 formwork moulds for tubbing production. And Commodore Cement Industries, LLC (CCI) has used these in the manufacture of over 100,000 tubbing segments all to European standards, despite the difficulties prevailing. The casting concrete was adapted to the extremely aggressive environmental conditions with the help of MC-Bauchemie. Eugen Kleen and his team specifically developed the super plasticiser MC-PowerFiow 1114 STEP for the concrete formulation, offering major advantages in consistency control and ensuring the ready compactability of the concrete. In producing the tubbings, CCI used around 100,000 m3 of this mix, which also needed to be highly resistant to both chloride attack and the extremely high sulphate contents of the soil encountered in the desert. In addition to the super plasticiser, MC provided a releasing paste from the Ortolan SEP product family. This creates a weathering-resistant film with outstanding formwork stripping efficiency- particularly important in the case of complex or detailed shapes. MC likewise supplied a sewage-resistant mineral repair mortar from the ombran product family used to seal porosities and blowholes and make good any flaking and spalling that may occur during production or subsequent installation on site.
The Cross rail C31 0 Thames Tunnel was also constructed using the tubbing method. It leads under the Thames, connecting Plumstead with North Woolwich. The project client was the railway company Cross rail, general contractor was the joint venture Hochtief Murphy. The tubbings were supplied by precaster Shay Murtagh. MC developed a special PCE super plasticiser for this work and supported the project from joint development of the concrete formulation with Hochtief through preliminary trials and on to local adaptation in the tubbing works of Shay Murtagh.
The tubbings used in Abu Dhabi were manufactured by Commodore Cement Industries, LLC with MC-PowerFiow 1114 STEP, a super plasticiser especially developed by MC-Bauchemie for this application and the difficult environmental conditions of the site. 162 formwork moulds were supplied by Herrenknecht for tubbing production. Data acquisition for quality management purposes was maintained across the entire process chain. Photos (left): Herrenknecht Formwork Technology GmbH.
A total of 34,500 track support slabs were manufactured and 69,000 m3 of concrete used for the newly constructed ICE rail link from Erfurt to Leipzig/ Halle. These components play an important part in the huge railway project aimed at creating an integrated European transport network. Products from MC help to ensure compliance with the exacting specifications applied to modern high-speed railway lines. This new section is part of the "German Unity Transport Projects" programme geared to providing communication links from Italy through to Scandinavia. The project in the Federal Republic of Germany has absolute priority, and therefore appropriately carries the title "Project No. 1 ".
A 123 km long standard-gauge twin-t rack section, designed to carry both high-revenue passenger and goods traffic, is currently under construction between Erfurt and Leipzig. As this had to be built for high travel speeds of up to 300 km/h, the choice fell on a tried and tested system developed by Austrian Railways and the company PORR. At the core of its technology are track support slabs of loosely reinforced concrete which are precast as high-precision components with integrated track support points. Once installed, they rest on a flexible barrier layer and are grouted with self-compacting concrete. The system offers the benefits of a minimum maintenance requirement together with sound and vibration damping. The order for production of the track support slabs for 90 km of the section went to the company Universalbeton Heringen GmbH & Co. KG, a long-standing partner of MC-Bauchemie. The precast concrete components had to be manufactured in high-precision steel formwork moulds, for which a particularly pourable concrete offering exceptional early strength was needed.
Universalbeton Heringen worked closely with Marko Bergmann, Sales Manager at MC, in the search for a suitable concrete formulation. "We carried out numerous tests and found that the best results were achieved with our new super plasticiser MC-PowerFlow 11 02;' explains Bergmann. When the client decided that it wanted to use a CEMI cement instead of the originally specified CEM II, MC-PowerFiow 1102 was able to produce just the results demanded. And the MC air entrainer Centrament Air 207 was also included as an admixture in order to make the concrete more malleable, easier to compact, more readily pourable and effectively resistant to frost and de-icing agents.
The track support slabs were manufactured between January 2012 and October 2013 in the precast concrete factory in Heringen, Germany. MC especially transferred part of the production of the requisite concrete admixtures to its works in Leipzig-Zwenkau in order to be able to ship out the large order quantities quickly and reliably. Before work began on installing the first track support slabs, 16,000 of them had to be precast and stored in Heringen in order to accommodate the required speed of construction. Finally, in the second phase, the track support slabs were installed along the site of the rail link and grouted with se lf-compacting concrete. The rail pylons were installed along the entire section using the highly flowable, fast-hardening and frost-resistant mast grouting mortar Emcekrete DBS-5 F from MC, a product that allows loading to commence within minutes and offers good adhesion to concrete and steel.
The rail link is scheduled for commissioning in 2015. Further lines are to be built in the next few years, with follow-up orders already having been placed with MC. Thus, "Project No. 1 "is gradually building up a head of steam.