Construction of road pavements using complex modified soil-cement

The object of research is the pilot industrial implementation of complex modified soil-cement in the construction of bases for flexible road pavements. The work aims to analyze the results of the pilot industrial implementation of soil cement modified with organosilicon compounds, polycarboxylate superplasticizers, and electrolytes in constructing bases for flexible road pavements. Method. The construction of road base layers from soil cement was done using the on-site mixing method. The construction of the remaining structural elements of the road structure (subgrade, asphalt concrete pavement) of the highway was carried out using standard technologies. The dynamic loading method determined the elastic modulus of the road pavement layers, the entire structure, and the roadbed soil by the static loading method. The effectiveness of the development and the legitimacy of the implemented scientific approach to the complex modification of soil cement was assessed by comparing the results of laboratory studies and industrial tests on highways. To determine the mineralogical composition and identify the products of new formations of soil-cement, X-ray phase, and differential thermal analysis methods were used. Results. A comparative analysis of laboratory research results and pilot industrial implementation of complex modified soil-cement and reinforced soils without modification during highway construction was carried out according to the following indicators: physical and mechanical properties, phase composition, and elastic modulus of the layer. Transitional-type road pavement designs with soil-cement foundations have been developed. The technology for carrying out work on the construction of a highway has been determined, including installing structural layers of the base of road pavements from cement soils using the on-site mixing method. The optimization of the compositions of complex-modified soil cement was carried out using the second-order rotatable planning method. Based on the developed road pavement designs, work technology, and optimization of the soil-cement composition, a highway was built with the construction of two sections to compare the effectiveness of the modification. Research has been carried out to determine and compare the elastic moduli of layers of road pavements and subgrades. The validity of the implemented scientific approach to using complex modification of soil-cement in constructing structural layers of road pavements has been confirmed.