WATER-REDUCING AND PLASTICIZING EFFECTS OF THE USE OF ADDITIVES OF SYNTHETIC CALCIUM SILICATES IN CEMENT COMPOSITIONS
Shoshin, E. A. Candidate of Technical Science, associate professor, Department \"Building materials and technology\", Yuri Gagarin State Technical University of Saratov, Russia
Strokova, V. V. V.G. Dr.-Ing, professor, Department of \"Materials and Materials Technology\", Shukhov Belgorod State Technological University, Belgorod, Russia
Alitinform №1 (54) 2019 г. 18-26 p.
The strategy of cement saving involves the use of concrete mixtures with a high content of highly dispersed mineral additives. It will allow to realize the effect of hardening the cement matrix in combination with significant (up to 70 %) cement substitution. The use of rock crushing screenings, ashes of thermal power plants, metallurgical production wastes is not economically attractive due to high logistics costs. At the same time, ground limestone and dolomite are characterized by relatively low dispersion. Synthetic calcium hydrosilicates have a greater dispersion compared to cement, their preparation can be adjusted from local silica-containing raw materials. Synthetic hydrosilicates can be a profitable alternative to imported highly dispersed additives. The article discusses the morphology of particles of synthetic silicate-calcium dispersion (SCD) and its influence on the properties of the cement system. SCD additives have a complex effect on the cement system due to a combination of high dispersion and features of particle morphology. The nature of the impact is determined by the dosage of the mineral additive. Depending on the dosage of the additive, the effects of plasticization, water reduction, compaction of the cement system or water-holding effect are observed. The high calcium content in the SCD composition determines the high efficiency of its interaction with plasticizers, which ultimately affects the effectiveness of plasticizers. The nature of the observed effects is determined.
synthetic silicates of calcium, morphology of particles, cement paste, plasticization, water reduction