Distinctive and highly visible, power plant cooling towers dominate the landscape as monuments to the energy industry. It is almost inconceivable that, despite their massive dimensions, these towers are extremely delicate concrete structures with walls only 20 to 80 centimetres thick. The planning and erection of these concrete constructions requires a high level of expertise and is the domain of only a few specialists throughout the world.
MC can call on forty years of experience in the construction of cooling towers. Over the years, comprehensive laboratory and construction site testing has resulted in continual system optimisation and has also provided the impetus for a series of new developments.
Since the 1980s, cooling towers at coal power stations have not simply been used to cool water, they have also been used to vent purified exhaust gas. This places a large number of technological requirements on the concrete shell of a cooling tower. In 2003, the construction of the world’s tallest cooling tower in the first ever lignite-fired power plant with optimised system technology in Niederaussem marked the start of a new chapter in technical cooling tower construction. Commissioned by RWE Power, this next-generation tower reached previously unheard of dimensions. It stretches 200 metres skywards with a base diameter of 145 metres. Special concrete technology solutions are required for an object of this size. To this end, a comprehensive concrete technology development process resulted in the creation of an acid-resistant, high-performance concrete capable of withstanding acid attacks. MC Bauchemie made a significant contribution to the associated research and development process through its silica technology.
The successful completion and smooth operation of this power plant encouraged the energy company to press ahead with two more lignite-fired power plants with optimised system technology in Neurath near Grevenbroich in January 2006. As with the Niederaussem power plant, the tried and tested high-performance concrete was again used for the two natural draught cooling towers. This power plant construction site is one of the largest in Europe. Up to 4,000 people are on site at peak times, all working to build one of the world’s most advanced power plants.
The two concrete giants were erected through a collaboration between MC and Alpine Bau Deutschland, the leading company for concrete work. Around 11,000 cubic metres of the high-performance, acid-resistant concrete were used for each of the cooling towers. The construction site was supplied with concrete prepared using dedicated mixing facilities set up on-site. The on-site manufacturing process ensured maximum quality of the ready-mixed concrete and excellent cost effectiveness at all times.
To ensure that the concrete was processed optimally, MC used a PCE high-performance flow agent that had been specifically tailored to this concrete formula (Muraplast FK 62.30 W.T.). “Centrilit Fume S2” was also used to regulate grain size distribution in the fine particle range, resulting in a high level of impermeability to infiltration by aggressive media. Centrilit Fume S2 is a new sedimentation-stable and highly reactive silica suspension with a particle size 50-100 times finer than the cement particles.
The concrete experts at MC ensured that quality remained high at all times. Prior to delivery, the special suspension and flow agent were subjected to testing in line with DIN ISO 9001 at MC’s laboratory in Bottrop. A further comprehensive quality check was carried out in a mobile laboratory at the construction site. After all, the quality of the concrete system used to construct the cooling towers is a deciding factor in both the longevity and, ultimately, the cost effectiveness of the plant.
When completed, each of the two towers reached a height of 172 metres. The diameter of the lower shell measures around 114 metres, with a waist of around 66 metres and an upper shell diameter of 69 metres. The striking, highly visible cooling towers of the Neurath power plant have already become a prominent new symbol for the Grevenbroich region.
