COMPARISON OF THE BEHAVIOR OF FIBER AND MESH REINFORCED SOILS

Abstract

Soft soil does not have good soil properties and is not suitable for constructing pavement structures as shear strength is required to resist the shear stress developed by traffic loading. To increase shear strength in this study, lime is used as the soil stabilizing agent and fiber and mesh are used as the soil reinforcement materials. The proper amount of lime added to soil will increase the shear strength as the lime-treated soil will decrease moisture susceptibility and migration. Shear strength of the lime-treated soil can be further improved by adding reinforcement materials such as fiber and mesh. The reinforcement materials will interlock with groups of particles and provide tensile strength to the soil matrix. The type of soil used in this study is high plasticity elastic silt with sand which is classified using the Unified Soil Classification System (USCS). Quicklime (calcium oxide) is used in this study at the minimum amount required for stabilizing the soil, which is 9%. The amount of fiber and mesh added to the soil sample is 0.5% of the dry weight of the soil used. Cylindrical samples were prepared with a moisture content of 22% (OMC) for untreated soil and 21% (OMC) for lime-treated soil samples. The lime-treated soil samples were cured for 7, 14, 28, 56, 90 and 120 days. Unconfined compression tests were conducted to determine unconfined compressive strength (UCS) and stress-strain characteristics. The unconfined compressive strength of the lime-treated samples increased as curing period increased but the failure strain decreased. The UCS and failure strain for reinforced lime-treated soil samples are higher than the unreinforced lime-treated soil samples.