Reducing the environmental burden during the reconstruction of highways by extending their life cycle

Abstract

The article presents the results of studies on assessing the effectiveness of using stabilizing additives of complex action (Chimston) to increase the bearing capacity of structural layers of the base of road pavements of the Far North highways due to its use in strengthening various types of non-cohesive soils in combination with an inorganic binder. It was found that the application of Chimston is unconditionally required, as the additive in the system allows one to obtain a material that meets the regulatory requirements for frost resistance and to ensure the reliable operation of the road structure in the conditions of the Far North. The maximum efficiency in terms of physical and mechanical characteristics with Chimston in the system was demonstrated by compositions based on crushed sand stabilized with 7 % cement, and for crushed stone-sand mixes of types C-7 and C-6 with 9 % cement. Based on the analysis of the obtained results, it can be assumed that the stabilizing additive Chimston, adsorbing on the surface of particles of sandy and coarse-grained soil, interacts with the inorganic binder of the composite. It affects the mechanism of its hydraulic activity in the process of gaining brand strength, which was most confirmed in the study of strength characteristics of samples based on coarse-grained soils. Thus, with an increase in the amount of binder in the presence of the Chimston additive, a higher increase in the compressive strength of the samples is observed. An increase in the amount of binder when adding an additive to the composition of samples based on coarse-grained soils contributes to the maximum gain in compressive strength of samples containing 9% cement. The obtained results allow for the conclusion that the technology of using the polymer stabilizer Chimston in the construction of structural layers of the base of road clothes based on loose soils can provide the required transport and operational condition of road structures with a life cycle of 24 years. It will also significantly reduce the volume of industrial waste used as pavement, as well as reduce the consumption of unsustainable Portland cement.