Tensile behaviors of natural fiber and cement reinforced soil subjected to direct tensile test

The present work was conducted to investigate the direct tensile behaviors including tensile strength, stress-strain curve, energy absorption, and crack patterns of soil reinforced by cement and natural fiber. In order to archive this, the direct tension test was designed to use for both reinforced and unreinforced specimens. The compacted 8-shaped samples with a wide range of cement content (0%, 4%, 8%, and 12%), fiber content (0%, 0.25%, 0.5%, and 1%), and curing days (7, 14, and 28 days) were prepared at optimum moisture content and maximum dry unit weight for the direct tension test. From experimental data, an empirical formula following three parameters (cement content, fiber content, and curing time) was proposed by using regression analysis. In addition, the effective degree of cement content, fiber content, and curing time on direct tensile strength was also examined based on the sensitive analysis. The experimental results showed that tensile properties (tensile strength, energy absorption capacity, and stress-strain curve) of cemented soil at low cement content and curing time were significantly improved with fiber inclusion. Direct tensile strength equaled to 0.483 and 0.071 times of splitting tensile strength and unconfined compressive strength, respectively. An acceptable regression model for predicting direct tensile strength was established. According to sensitive analysis, the ascending orders of effective parameters on direct tensile strength were fiber content, curing time, and cement content.