Influence of anthropogenic waste of different genesis on properties of fine-grained concrete

Abstract

Introduction. The growing amount of stored waste from TPPs has a negative impact on the environmental and economic situation in Russia. The content of ash dumps leads to pollution of nearby areas and increase in energy prices. To solve this problem, it is proposed to use TPP waste as a component of solutions. Materials and methods. The equipment on which the experiment was performed is listed. For the test of compressive strength, the press TP-1-350 Universal was used. For the test of flexural strength, MII-100 machine was used. Specific surface area of TPP waste was determined on PSKh-12 device. The samples gained the strength in the chamber of normal hardening. The chemical composition of TPP waste was determined by the X-ray fluorescent method. Results. The experimental data on the strength of specimens with the replacement of part of the cement by waste thermal power plants of different genesis are presented. The part of the samples were cured under normal conditions, and part was subjected to heat and humidity treatment. Specific cement consumption per unit of compressive and flexural strength was calculated. Compressive strength of mortars with replacement of 20% of cement by Kuznetsky TPP ash makes it possible to obtain samples with strength by 8% less than the control sample under normal curing conditions. The use of acid ash from Omsk TPP and Kuznetsky TPP under heat and moisture treatment makes it possible to obtain the samples with compressive strength higher than the control sample up to 13%. The introduction of 30 % of the basic ash from Novosibirsk TPP instead of cement allows to obtain samples with compressive strength up to 46,55 MPa. The calculation of specific consumption of cement per unit strength showed that the use of the proposed compositions is more cost-effective than the control ashless sample up to 30%. Discussion and conclusions. It has been proved that replacement of up to 30% of cement by TPP wastes makes it possible to obtain mortars with strength not lower than that of the control cement sample. Depending on curing conditions and the type of used TPP waste it is possible to receive samples with compressive strength up to 46,55 MPa and bending strength up to 9,31 MPa. It was found that the use of heat and moisture treatment for the samples using basic ash does not give an increase in strength, compared to acidic ash.