THEORETICAL DESCRIPTION OF WATER DISTRIBUTION IN CONCRETE MIX-TURES ON LIGHTWEIGHT AGGREGATE

Based on the models considered, it has been demonstrated that a lower density of hollow agreegate requires a smaller amount of it to achieve a given density of lightweight concrete. This provides greater variability in the development and design of the frame-forming part and creates the potential for achieving high mechanical properties. The proportion of adsorption water of a hollow aggregate does not depend on the total amount of water in the system, in contrast a porous aggregate. This allows predicting water consumption and managing the rheotechnological properties of mixtures based on them. The distribution of physically bound water in compositions on hollow aggregate is different from that in compositions on porous aggregate. The proportion of physical water on such an aggregate is greater than on a hollow one for compositions with a density of no more than 1500...1600 kg/m3. If the density is less than this range, then in hollow aggregate systems a higher content of such water is observed. It is shown that the distribution of water in systems on porous and hollow aggregate differs significantly. Considering the role of porous aggregate in forming the structure of lightweight concrete, it can be assumed that when developing lightweight concrete with a density of more than 1600 kg/m3, it is advisable to use porous aggregate. When developing lightweight concrete with a density of less than 1600 kg/m3, it is advisable to use hollow aggregate. This ensures rational distribution of water in the concrete mixture and, consequently, conditions for the formation of a strong structure of lightweight concrete.