An Investigation into Performance of Cement-Stabilized Kaolinite Clay with Recycled Seashells Exposed to Sulphate

• Main Authors: Amin Chegenizadeh, Mahdi Keramatikerman, Faizan Afzal, Hamid Nikraz, Chee Keong Lau
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Sustainability
• Subjects: clay; geotechnical engineering; infrastructures; seashell; sulphate attack
• Online Access: https://www.mdpi.com/2071-1050/12/20/8367

<b>: </b>Sulphate attack is one of the key issues in geotechnical engineering. This study aims to investigate the efficacy of the seashell to reduce negative impacts of the magnesium sulphate concentration on the cement-stabilized clay mixtures by performing a series of unconfined compressive strength (UCS) tests. Three percent of cement (3%, 5% and 7%) was utilized in this study. In addition, the benchmark and exposed specimens were cured for 7, 14, and 28 days before testing and exposure, respectively. A series of the compaction tests were conducted and the optimum moisture content (OMC) and maximum dry density (MDD) values were achieved. In the next stage, the UCS tests were performed on the specimens containing 10%, 20%, or 30% seashell contents and the specimens were exposed to sulphate concentration. Scanning electron microscope morphology had indicated that seashells are a suitable replacement for cement. Qualitative X-ray diffraction had shown that the presence of magnesium sulphate reduces the formation of calcium silicate hydrate, which causes durability issues in cement-stabilized soils. The results indicated that seashell is effective to improve the sulphate resistance of cement-stabilized soil.