Effect of powdered recycled tire on sulfate resistance of cemented clay

Abstract

Magnesium sulfate (MgSO4MgSO4) attack is a major problem in geotechnical engineering projects, as exposure to sulfate can affect soil integrity. Lightweight recycled materials such as used vehicle tires can be used to improve the geotechnical properties of soil, while also eliminating landfill. This study investigated the effects of addition of powdered recycled tire (PRT) on the sulfate resistance of cemented clay specimens cured for 7, 14, and 28 days. A total of 74 unconfined compressive strength (UCS) tests were conducted on benchmark (unexposed) and MgSO4MgSO4-exposed specimens. Addition of PRT improved the peak UCS values (ququ) in both conditions. Microstructural analysis by X-ray powder diffraction and scanning electron microscopy was performed on selected benchmark and MgSO4MgSO4-exposed specimens. Exposure to MgSO4MgSO4 reduced the generation of hydration products such as calcium silicate hydrate (CSH), resulting in poor connections between PRT and soil particles.