Experimental Study on Strength Behavior of Clayey Soil Reinforced with Glass Fiber

This study demonstrates the strength characteristics of a clayey soil reinforced with randomly distributed glass fibers by means of unconfined compression (UC) and California bearing ratio (CBR) tests for its application as a subgrade material for flexible road pavement. A low plastic clayey soil (CL) was mixed with 20 mm glass fibers in different proportions up to 1% by dry weight of soil. The test results show that the UCS and soaked CBR values of the clayey soil improve markedly with glass fiber inclusion along with modulus and energy absorption capability (EAC). Inclusion of glass fiber significantly reduces brittle behavior of the clayey soil by increasing the failure axial strain and decreasing post-peak strength loss, and this can be noted from the specimen failure mode. The UCS, CBR and subgrade modulus values are noted to increase with fiber content and reach their optimum values at 0.75% fiber content. The soil ductility increases continuously with fiber content. Increasing EAC indicates that the reinforced soil needs higher energy for its deformation, and has better bearing capacity. The glass fiber is found to be a good reinforcing material with the clayey soil for its application as subgrade material of low-volume flexible road pavement.