Study on anti-corrosion of PVA-treated wheat straw and its application in reinforcement of a silty soil

•The polyvinyl alcohol (PVA) treated wheat straw is greatly improved in terms of anti-corrosion.•The optimum concentration of PVA solution and immersion duration are suggested.•The strength of the silty soil reinforced with the treated wheat straw is increased. Silty soils are usually with poor mechanical performance and thus need reinforcement to meet the requirements in geotechnical practices. Wheat straw is low-cost, environment-friendly and wide spread, which has a great potential for use as reinforcement of the silty soils. In this study, the anti-corrosion effect of polyvinyl alcohol (PVA) treated wheat straw was investigated through the pore area ratio tests and the tensile tests. Test results indicated that the wheat straw was greatly improved in anti-corrosion, and tensile strength was considerably enhanced after the treatment. The optimum concentration of PVA solution and immersion duration were suggested. The PVA-treated wheat straw was then buried in the silty soil, and its corrosion resistance to the environment in the soil was validated under different moisture conditions. The treated wheat straw was then used as the reinforcing material for improvement of a silty soil. Triaxial compression were carried out on the samples reinforced with the material of various inclusion contents and lengths. Stress–strain curves and strength of the reinforced soil samples were analyzed, and the optimum inclusion content and length were discussed. The California bearing ratio (CBR) tests were then performed for the reinforced soil with the optimum inclusion content and length, and the test results showed that the reinforced silty soils met the requirements on CBR of the subgrade.