Abstract:

Increasing quality and durability requirements of concrete and reinforced concrete products lead to the growth of quality requirements not only of the main raw materials but also additional, for example, admixtures. Therefore, many effective admixtures, which have a negative impact on the quality of concrete are taken out of use. These include calcium chloride, which causes corrosion of concrete reinforcement. Hence, developing and introducing new admixtures that would combine high main effect and the lack of negative impact on the concrete quality is reasonable. The influence of the experimental admixture DOR № 1 on physical and mechanical properties of the cement and the formation rate of bound water in the hardening of the latter was investigated. The admixture DOR № 1 is the product of the processed polymer fraction of municipal solid waste and consists of amides and ammonium salts of the terephthalic acid. It was found that the admixture DOR № 1 accelerates cement setting and hardening under normal and low temperatures, but has a selective efficiency, which depends on the admixture concentration, cement type and temperature conditions. Cement hardening acceleration occurs due to increased solubility of clinker minerals, which in turn increases the formation rate of the gel-like phase, calcium ions and accelerates crystallization of calcium hydrosilicates, which increases cement strength. The results confirm the possibility of using the admixture DOR № 1 as a cement setting and hardening accelerator. The admixture can be used for concreting under different temperatures. Author Biographies Ганна Юріївна Флейшер, National Technical University of Ukraine "Kyiv Polytechnic Institute", 37, Prospect Peremohy, 03056, Kyiv-56 Postgraduate Department of chemical technology of composite materials

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