Strength and swelling properties of a waste tire textile fiber-reinforced expansive soil

Expansive soils are problematic for their relatively low load bearing capacity and extensive swelling-shrinkage deformations. Therefore, treatment of such soils is often considered to be necessary prior to construction. This paper investigates the potential of reusing waste tire textile fibers (WTTFs), a byproduct of the treatment process of end of life tires (ELTs), as reinforcement materials for treatment of expansive soils. To that end, mechanical reinforcement of sodium bentonite by WTTF inclusion has been evaluated through a set of standard compaction, direct shear, Unconfined Compressive Strength (UCS), California Bearing Ratio (CBR), and swelling-consolidation tests. Six different WTTF contents – that is, f_c = 0%, 0.5%, 1%, 2%, 3%, and 4% were used and investigated. It was proven that WTTFs can improve the shear strength and UCS parameters. Swelling deformations of the soil were demonstrated to reduce by as much as 44%. At low WTTF contents, CBR was enhanced marginally. However, this parameter decreased at high WTTF contents. Therefore, it can be concluded that WTTFs can be used as economical reinforcement materials in expansive soils to enhance the strength parameters, mitigate the swelling properties, and address an environmental concern regarding WTTFs.