EXPERIMENTAL STUDY ON STRENGTH OF SAND REINFORCED WITH COMPOSITE REINFORCEMENT AGENT

This paper aims to examine composite curing method based on polymeric soil consolidator and fiber material to reinforce the sand. Especially the test uses different concentrations of polyurethane curing agent and different content polypropylene fiber. All of the composite soil samples are subjected to the direct shear test and the unconfined compression test in this experiment. The results and the mechanism are discussed. The following are found. When the composite reinforcing agent in curing agent concentration is certain, unconfined compressive strength and cohesion of sands increase first and then decrease as the fiber content increases. They reach their peak values at the fiber contents of 0.3% and 0.2%.When the fiber content of composite reinforcement agent is certain, the unconfined compressive strength and cohesion restriction of sands increase as the curing agent concentration increases, but the angle of internal friction has little change. Finally, composite reinforcing agent is a combination of physical and chemical reinforcement methods. It can quickly and effectively improve the strength of sand, and also provide a reference for the further research and application of composite reinforcement materials.