APPLICATION OF ASHES FROM THERMAL POWER STATIONS IN CONCRETE

Abstract

The analysis of experience of application of the ashes of thermal power stations in concrete is made. It is shown that influence of ashes on physical and mechanical properties of concrete is defined by a chemical compound, content of free calcium oxide and magnesium oxide, value of a specific surface. Results of research of a cement stone and concrete with the additive of woody ash are presented. It is determined that woody ash possesses a high water demand. The increase in quantity of ash leads to loss of concrete mix workability. It is determined that replacement of 5 – 10 % of cement with ash leads to a 15 % reduction of strength of concrete. Concretes with the additive of woody ash have lower density. Ash input in concrete mix in combination with superplasticizer additive allows to reduce a water-cement ratio and at the same time saves the required fluidity and provides compression strength of concrete not below control concrete sample.