The effect of water content on shear and compressive behavior of polymeric fiber-reinforced clay

Soil reinforcement is a reliable and effective technique for enhancing soil resistance. The present study aims to investigate the impact of water content on the mechanical behavior of a fiber-reinforced clay. To this end, clay specimens were prepared with three water contents (15%, 17.5%, and 20% by clay weight) and three contents of fiber (0.1%, 0.2%, and 0.3% referred to clay weight). Next direct shear and unconfined compressive strength tests were performed to study the effect of water content on the modulus of elasticity, compressive strength, strain energy, shear strength, shear strength ratio, stress–strain behavior, internal friction angle and cohesion coefficient of the prepared clay. The results indicate when the water content is lower than the optimum moisture content (OMC), fiber decreases modulus of elasticity and increases ductile behavior, compressive and shear strength, strain energy, shear strength ratio and cohesion coefficient but when the water content is more than the OMC, fiber increases brittle behavior, compressive and shear strength, strain energy, shear strength ratio and friction angle.