Experimental studies on compressive and tensile strength of cement-stabilized soil reinforced with rice husks and polypropylene fibers

• The reinforcement effects of rice husks and polypropylene fibers on mechanical performance in three types of cement-stabilized soils are studied. • Several factors including fiber content, initial moisture content, and curing time are investigated. • The most effective strengthening range of fiber content is 0.3%-0.5%. • Rice husk shows a clear advantage in the soil with higher content of cohesive particles. This paper innovatively proposes the use of natural rice husk for reinforcing stabilized soil, and the experimental results exhibit the application potential. The reinforcement effects of rice husks and polypropylene fibers on mechanical properties in three types of cement-stabilized soils (clayey sand (SC), sandy clay of low liquid limit (CLS), and low liquid limit clay (CL)) were comparatively studied by conducting compressive strength tests and splitting tensile strength tests. The influence parameters evaluated were the fiber content, the initial moisture content, the curing time, and the fiber type. The experimental results reveal that the addition of rice husks and polypropylene fibers in cement-stabilized soil significantly improve the unconfined compressive strength (UCS) and split tensile strength (STS). The UCS and STS of fiber-reinforced soil exhibit the same trends of increasing first and then decreasing with the increase of fiber content, and the most effective strengthening range of fiber content is 0.3%–0.5%. Rice husk shows the better reinforcement effect on UCS in cement-stabilized SC and CLS, and shows better reinforcement effect on STS in three types of cement-stabilized soils, while polypropylene fiber only shows the better reinforcement effect on UCS in cement-stabilized CL.