Application of sawdust in civil engineering projects, specifically those with geotechnical applications, has been the interest of many studies. This study focuses on exposure of soil samples treated with sawdust to MgSO4. This study was conducted in three stages. The first stage was compaction. In this stage, the compaction characteristics of each mixture were derived. The second stage was to run unconfined compressive strength (UCS) testing and report the UCS peaks relevant to each mixture. The third stage was microstructural examination (i.e., SEM) conducted on the chosen samples before and after sulphate exposure to highlight the reactions during exposure. The results of first stage (i.e., compaction tests) suggested that increasing sawdust content, the OMC (Optimum moisture content) decreased and MDD (Maximum dry density) decreased. In the second stage, the UCS (Unconfined compressive strength) testing was conducted on 640 samples [including reliability tests] and the outcome suggested that sawdust increased the resistance of samples against sulphate attack. In stage three, the micro analysis backed the main body results, suggesting that sawdust had a positive effect on helping to form a better connection between the particles and therefore more resistance noted.

This experimental work aims to understand the influences of two types of waste materials, namely crushed rock and crushed glass, on the shrinkage characteristics of cemented bentonite. The cemented bentonite specimens were prepared by mixing clay with 15 and 25% cement content by dry weight of soil. Three different percentages of glass and rock content (2.5, 5, and 10%) were adopted in this work. The samples of cemented clay with and without the waste materials were allowed to cure for 7 and 14 days before the shrinkage process. The results indicated that the combination of crushed glass and cement effectively reduces the shrinkage of bentonite. A slight decrease in axial and radial shrinkage strain appeared when crushed rock was applied to cemented bentonite. Additionally, considerable improvement in the shrinkage behavior of the cement-treated clay was associated with curing time and an increase in the chemical agents.