HIGH-STRENGTH LOW WATER DEMAND CEMENTS

The type and properties of cement are key factors in the development of high-strength and ultra-high-strength concretes (B80-B150 and higher). The most promising type is low water demand cement (LWDC), which surpasses all industrial ce-ments in technological, strength, environmental and economic indicators due to high dispersion and the effect of low water demand. The article presents the results of the development of high-strength LWDC intended for obtaining high-performance fine-grained concretes of a new generation. The state of the art in terms of the relevance of the research topic is studied. Experimental dependencies of normal consistency and mobility, strength of cement stone and activity of LWDC-100 (100% Portland cement content) with a specific surface area from 5000 cm2/g to 9500 cm2/g obtained by joint grinding of standard cements CEM I 42.5N and CEM 0 52.5N with different contents of the superplasticizer "Polyplast PC" (type R) are obtained. Optimum compositions of LWDC-100 on these cements achieve compressive strength of cement stone of 212 and 231 MPa, respectively, and activity (strength of cement-sand mortar) – 93 and 112 MPa with a specific surface of 7300 cm2/g and 6600 cm2/g. This allows them to be recommended for obtaining high-strength and ultra-high-strength concretes.