Every professional dedicated to his trade can feel morally satisfied when knowledge matched with experience and creative inspiration leads to the unique achievements that can influence progress in their area of activity. These are the feelings that fill the specialists of the concrete institute NIIZhB (a research, design and technological institute for concrete and reinforced concrete) and the Master Beton enterprise who have taken part in the development and large-scale introduction of new-generation concretes showing high performance, as well as in the creation of organic and mineral modifiers of MB series that are utilized to produce such concretes.
Due to the general science and technology advance the concrete technology underwent significant changes at the end of the 20th century that have an exponential, so to speak explosive character. New-generation concretes modified by high efficient admixtures came to life, they considerably surpass common concretes in various parameters. New notions and terms were coined, some conventional structural and technological standards were altered.
Today the ensign of progress in concrete science and technology is associated with high-strength (compressive strength of 80 to 120 MPa) and very high-strength (above 120 MPa) heavyweight and fine-grained concretes with low permeability and increased corrosion resistance, self-compacting concretes with cone slump no less than 28 cm corresponding to spread of 65-80 cm, concretes with enhanced deformability characteristics and with shrinkage compensation. All of them are frequently described as High Performance Concrete implying high strength, durable and processible concretes.
Featuring high quality in all of their forms they are already of high practical value, being applied as the main structural material of singular engineering edifices.
Examples of successful application of high performance concrete to realize various construction projects date back to the 80-ies. To name a few, these include a high rise complex in Chicago, a tunnel beneath the English Channel, an overpass bridge across the Northumberland Strait in Canada, a number of bridges in Japan, Norwegian offshore drilling platforms in the North Sea, The projects of the latest period are especially striking from the aesthetic and structural point of view: Petronas Twin Towers in Malaysia, the world’s highest building of those already commissioned Taipei 101 in Taiwan and the Burj Dubai Tower that is under construction in the UAE.
The key factor to the production technology of such concretes lies in multipurpose utilization of dispersed materials possessing high pozzolanic activity, chiefly microsilica and superplasticizers.
However despite the overall attractiveness of the new-generation concretes the geography of the construction projects based on them is hardly broad enough. And this happens not only because the complex unusual buildings are not constructed worldwide. The main reason is microsilica lack of workability, for this dust-like ultrafine material of 150-200 kg/m3 bulk density is extremely unsuitable for transportation.