INFLUENCE OF MINERAL ADDITIVES OF TECHNOGENIC ORIGIN ON THE STRENGTH PROPERTIES OF SOIL BASES AND SOIL-CEMENT FOUNDATIONS

Abstract

It was analyzed technological solutions for increasing the strength of soil cement. It was determinated that fly ash is one of the most studied technogenic products. Feasibility studies show that the use of ash and slag waste from thermal power plants in the production of concrete and reinforced concrete products allows reducing cement consumption. In order to increase the strength of soil cement, it is proposed to add fly ash additives in the amount of 5 wt.% of the mass of cement in the manufacture of soil cement. It was determinated that the addition of fly ash in the amount of 5 % of the mass of cement can improve the strength of samples after 28 days by 16.9 %. Adding residual sludge from sewage treatment plants to the soil cement composition is a modern method of comprehensive utilization of industrial waste. This allows solving environmental and engineering problems simultaneously. In such a system, sediment acts as an organo-mineral microfiller. Due to its finely dispersed structure, it fills the pores between soil particles and increases the density and water resistance of the finished material. The key factor limiting the use of raw sediment is the high content of organic substances, which prevents normal hydration of cement. Therefore, we observe a decrease in the strength of soil cement when adding 10 % of dried residual sludge from sewage treatment plants. However, when adding 5 % of residual sludge to soil cement, the strength values did not change significantly. It was determined that adding 5 % of dried sludge to soil cement will not significantly affect the strength of soil cement. It was found that the strength of soil cement with the addition of 5 % of sewage treatment plant sludge or fly ash will increase over time, as in soil cement without the addition of additives. However, the pace of this growth and the final figures will vary.