New high-strength materials are examined in the construction of concrete pavements and bridges in the development of modern civil engineering and one also works on the improvement of the characteristics of existing materials. The concrete is examined, which keeps the characteristics of „ classic concrete“, and is resistant to external impacts and aggressive agents and has high esthetical value and economic justification of utilization. There are restrictive conditions for wider utilization of classic concrete due to slowed hardening, often insufficient tensile strength, small chemical resistance, and the appearance of cracks during the drying, large capillary porosity. Special attention is paid to “life-cycle“ of the construction. The experiences in the area of self-compacting concrete (SCC) and its advantages in comparison to classic concretes are presented in this paper. Methods of examination of fresh SCC and the results of laboratory testing with the examples of concrete mixes which possess the characteristics of SCC are also presented. (Author/publisher)
Samenvatting