OPTIMIZATION OF EXPANDED CLAY CONCRETE MIX FOR MODULAR STRUCTURES WITH CONSIDERATION OF SUSTAINABILITY

The purpose of this study is to experimentally substantiate the effect of the concrete mixing method on the physical and mechanical characteristics of expanded clay concrete used in modular construction. As part of the study, two technological approaches to mixing were compared: the traditional (according to GOST) and the alternative method of "suspension concrete". The study was carried out on identical compositions of lightweight concrete with expanded clay aggregate fractions of 0-10 mm at a constant dosage of cement, sand, water and chemical additives. For each mixing method, control samples were produced and compressive strength tests were performed at the ages of 1, 3, 7 and 28 days, and the average density of the samples was determined. The results showed that changing the order in which the components of the concrete mix are introduced has a significant effect on the formation of the material structure. The use of the suspension mixing method, in which a cement-water suspension is formed before the introduction of aggregates, provided an increase in the strength of expanded clay concrete up to 19% on day 28 compared with traditional technology. In addition, an improvement in the uniformity and surface quality of the samples was noted. At the same time, the workability and density of the concrete mix remained at the same level. Thus, suspension mixing can be considered as an effective way to intensify the structure of expanded clay concrete without changing the composition, which is especially important in the context of industrial production of prefabricated products. The data obtained are of practical importance and can be used to improve manufacturing technologies for lightweight concretes with enhanced performance characteristics.