Cement concrete modified by fine-dispersed anionactive bitumen emulsion for road construction

Abstract

Cement concretes are strong and able to resist external adverse environmental factors, have an increased water absorption and, as a result, insufficient frost resistance and deformability. Therefore, wide use of cement concrete in road construction is limited. Modification of road cement concrete with anionactive bitumen emulsions is a current and promising solution. By introducing small concentrations of bitumen emulsions into cement concrete, one gets a material with the basic properties of cement concrete and the properties of asphalt concrete. Rigid crystallization bonds formed as a result of cement hydration are dominantly present in cement systems, while coagulation type bonds with adhesive properties bitumen prevail in asphalt systems. Depending on the quantitative relationship between these bonds, the deformability of concrete tends to change. The main technological and operational properties of the resulting road cement concrete were investigated. Cement concrete was bituminized by introducing the anionic bitumen emulsions into the concrete mixture (from 0.5% to 8.0% of cement weight), which allowed increasing technological properties of concrete mixture and the performance properties of hardened concrete. This increases mobility, improves deformability of hardened concrete, increases its abrasion resistance, water resistance, frost resistance, reduces shrinkage without reducing the strength properties of road concrete.