Weak coastal subgrade soil stabilization using cement and palm date fibers

Soil stabilization is an effective method employed in order to improve soil properties, using different stabilization agents. As well using fibers as reinforcement of weak soils which generally have no tension and low bearing capacity is a well-known method. This study has investigated simultaneously using of palm date fibers and cement in order to improve the key characteristics of a specific soil type in Qeshm island. Cement was used as the main soil stabilizer and palm date fibers were included in soil composite as a reinforcing elements. The palm fibers in date production have filament texture with special properties such as: low cost, plenitude in the region, durability, light weight, tension capacity and relative strength against deterioration. In this study, test specimens, with a fixed cement content (6%), were fabricated including different fiber content (%0.5 and %1.0). The specimens were cured 7 and 28 days and were immersed in water for four hours prior to indirect tensile strength (ITS) and unconfined compressive strength (UCS) tests. As well, CBR specimens were cured (7 and 28 days) and tested in both optimum water content and saturated conditions. Compaction tests results shows that increasing fiber content in soil result in decrease of maximum dry density and increase of optimum moisture content. ITS and UCS results shows the most improvement in tensile strength (almost %48) and compressive strength, for %0.5 fiber inclusion. CBR test results shows that CBR values has increased with increase in fiber content in the soil.