SELF-COMPACTING FINE-GRAINED ASH-CEMENT MIXES WITH A POLYFUNCTIONAL MODIFIER

Abstract

The possibility of modifying self-compacting fine-grained concrete with polymer admixtures has been established. A polyfunctional modifier, including the polycarboxylate superplasticizer Melflux 2651f and polyvinyl acetate dispersion (PVAD), can reduce the water consumption of cement and cement-ash pastes by 13...19%.

It is noted that the addition of polyfunctional modifier changes the structure of cement and cement-ash stone, changing the parameters of its pore structure, causing an increase in the volume of closed pores, reducing the average pore size and increasing their uniformity.

Experimental-statistical models of water consumption, water separation, and air content of self-compacting fine-grained concretes with polyfunctional modifier admixtures were obtained, depending on the composition parameters. At a dosage of superplasticizer up to 1%, the water separation of self-compacting mixtures practically does not increase, and then tends to increase.  The polyvinyl acetate admixture in the composition of the polyfunctional modifier provides a decrease in water separation over the entire interval of its content - up to 3%. The introduction of polyfunctional modifier provides a stable air entrainment of self-compacting concrete mixtures and helps to maintain their workability over time.