Effect of fiber dispersion, content and aspect ratio on tensile strength of PP fiber reinforced soil

The present study was conducted to investigate the tensile strength characteristics of polypropylene (PP) fiber reinforced soil with different fiber dispersion, content and aspect ratio. In order to investigate this, the experimental programme was comprised by the test with a wide range of fiber content (0.35%, 0.60%, 0.85%), fiber aspect ratio (150, 225, 350), and mix patterns (discrete or random distribution). The results indicated that increases in fiber content caused an increment in the tensile strength whether discrete or random distribution. The increasing extent of tensile strength was different with increase of fiber aspect ratio under different fiber mix patterns. From experimental data, a genetic programming (GP) model was proposed for analyzing tensile strength contrast of the two mix patterns. In addition, the sensitive analysis of three inputs showed that aspect ratio has the greatest influence on the forecasting model. The effectiveness of the GP model was validated by the test results, and the robust model developed would provide a theoretical support for roadbase designing and construction which were reinforced with PP fibers.