Swell and microstructural characteristics of high-plasticity clay blended with cement

Abbey, Samuel Jonah; Eyo, Eyo Umo; Ngambi, Samson

Abstract

This study presents the effect of high plasticity on swell potential, swelling pressure and micro structural characteristics of kaolinite-bentonite mixed clays. Five different combining ratios of kaolinite bentonite mixture of 100:0, 90:10, 75:25, 50:50 and 25:75 in % by weight of dry kaolinite were used. All five synthesised soils were then mixed with 0%, 5% and 8% of cement by weight of dry soil, cured for 28days and subjected to Atterberg limit, one dimensional oedometer and scanning electron microscope test. The inclusions of 5% and 8% cement reduces the plasticity index of the treated soils as the percentage of bentonite increases. The effects of plasticity of treatment with 5% and 8% cement after 28 days curing period, was evaluated, and the results show that reduction in plasticity index resulted to decrease in swell potential and swelling pressure of the kaolinite-bentonite mixed clays. The results of micro-structural analysis of 5% cement treated soils show formation of flocculated fabric and cementation of soil particles, and filling with cementitious compounds of the voids of flocculated fabric in the soil. The reduction in swell can be attributed to the resulting compacted and dense mass of treated soils due to cementation of soil particles and cation exchange. The complex behaviour of swell of high plasticity kaolinite-bentonite mix has been explained using one dimensional oedometer test, by further experimental study and examination of the micro-structure of treated soils.

• Journal Article Type: Article
• Acceptance Date: Sep 25, 2019
• Online Publication Date: Dec 5, 2019
• Publication Date: 2020
• Deposit Date: Oct 4, 2019
• Publicly Available Date: Dec 23, 2019
• Journal: Bulletin of Engineering Geology and the Environment
• Print ISSN: 1435-9529
• Electronic ISSN: 1435-9537
• Publisher: Springer (part of Springer Nature)
• Peer Reviewed: Peer Reviewed
• Volume: 79
• Pages: 2119-2130
• DOI: https://doi.org/10.1007/s10064-019-01621-z
• Public URL: https://uwe-repository.worktribe.com/output/3504687