Reduction Of Soil Swell Potential With Fiber Reinforcement

Abstract

Fiber reinforcement of soils can reduce displacements due to swelling and shrinking of expansive soils. Described in this paper is a series of laboratory tests performed on fiber reinforced and non-reinforced samples of expansive clay to determine the potential for using fiber reinforcement to resist swell displacements. The testing program includes a series of one-dimensional free swell tests performed on 10.2-cm diameter and 6.4-cm diameter specimens of reinforced and non-reinforced expansive clay using an expansion index test device and fixed ring consolidation cells. Specimens used for this testing program were prepared at different fiber dosage rates over a range of compaction moisture contents. Results of these tests show that inclusion of discrete fibers in expansive clays significantly reduces volume change when subjected to one-dimensional free swell conditions. As a result, there appears to be great potential for reducing the detrimental effects on buildings, earth retaining structures and roadways induced by soils with a high potential for volume change or expansion. The importance of fiber dosage rates and compaction moisture content are discussed and the issue of adequate sample size for testing of fiber reinforced soils are addressed.