Material Laboratory Testing of the Sub-Ballast Protective Layer with Binding Agents

The importance of the reinforcement of the subgrade and particularly of its main platform is conditioned by the increase in train axle load. The analysis of the results of testing of the strength and deformation characteristics of recycled ballast material during improved with binding agents with the addition of polymer stabilizers has been conducted to assess the applicability of soil consolidation technology when arranging a sub-ballast protective layer. Laboratory testing has allowed to obtain the dependences of compressive strength and bending stretch on the percentage of Portland cement and polymer stabilizer, and to assess the decrease in material properties when exposed to an aggressive environment. The testing has resulted in selection of optimal composition of cement and stabilizer for agiven granulometric composition of sub-ballast protective layer and allowed to reveal main advantages of the use of soil stabilizer as compared with the samples with the use of cement only.