The article studies the production of cement concrete for road surfaces using microdosages of ultrafine additives obtained by hydrolysis of soluble inorganic salts. The particle size analysis of additives at laser particle analyzer showed that the granulometric composition of colloidal calcium hydroxide particles, a product of salt hydrolysis, was characterized by a polymodal distribution, and the average particle size was in the range of 1.68–1.97 μm. The article highlightes the influ-ence of cement consumption, the type and quantity of mineral micro-fillers, the type of ultrafine additives and superplasti-cizer on the physical and mechanical properties of concrete. The obtained concrete has a compressive strength class of B30-B35 and a bending strength class of Btb4.0, with a frost resistance class of F2200 and a water resistance class of W10.The influence of ultrafine additives, micro-fillers and superplasticizer on the properties of concrete has been evaluated. It has been established that the most rational compositions are concrete mixtures containing 5-20% fly ash and ground dolomite when replacing cement in concrete. The content of micro-filler additives is determined by the requirements for con-crete for various structural layers of road structures. It has been proven that by adding an ultrafine additive and ground dolomite up to 15% to the concrete mixture instead of cement, concrete for road surfaces can be obtained, characterized by a dense structure and strength characteristics almost the same as the control composition. The combined use of an ultrafine additive, superplasticizer and micro filler reduces the water-cement ratio, improves the mixing quality and uniformity of the concrete mix and reduces its tendency to segregation.
L.A. URKHANOVA (Tue,) studied this question.