Use of ash-slag mixtures for the construction of road base layers

Abstract

The article provides information on the volume of formation of ash and slag waste from coal combustion, and the volume of their utilization. This is general information on the volume of formation of ash and slag by-products in foreign practice, and their practical and effective use. In world practice, ash and slag are usually used in the production of building materials, such as concrete, asphalt concrete mixtures, bricks, ceramic tiles, thermal insulation, etc. The involvement of these materials in the technological process of road construction will reduce the negative impact on the environment and expand the resource base of the industry. Ash and slag waste consist of a combination of ash-carryover and fuel slag, which have fundamental differences in their structure.

During the conducted research, an assessment of the deformation characteristics of this technogenic soil was performed depending on the degree of its compaction and humidity. The analysis showed an increase in density by 0.01 units. The compaction coefficient gives an increase in the modulus of elasticity from 6% to 7%, and the modulus of deformation from 2% to almost 5%. The influence of humidity on the deformation parameters of ash-slag mixtures is significant, although somewhat lower than the influence of density. Moreover, at optimal humidity, the value of the modulus of elasticity and deformation is the smallest.

Analysis of the chemical and phase compositions of ash-slag mixtures indicates the similarity of these technogenic soils with natural sandy and clay soils. However, the structure of ash-slag mixtures determines a number of significant features compared to natural soils. Comparison of the magnitude of the modulus of deformation of natural soils and ash-slag mixtures shows that this indicator in technogenic soil is somewhat lower than in sandy soils, but is not inferior to natural clay-dusty soils.

Its suitability as a building material for the construction of base layers of road pavements of highways was assessed.