Engineering properties of tropical clay and bentonite modified with sawdust

Akinwumi, Isaac; Ojuri, Omoleye; Ogbiye, Adebanji; Booth, Colin

Abstract

Construction Engineers typically avoid the use of expansive soils as construction materials because they are usually difficult to work on and can cause structural failure. This research work investigates how the application of sawdust to tropical clay and bentonite influences their geotechnical properties in order to determine their suitability for use as landfill liner materials for the effective containment of toxic substances from landfills. X-ray diffractometer, X-ray fluorescence spectroscopy and scanning electron microscopy were used to determine the mineralogical composition, oxide composition and microstructure, respectively, of the clay and bentonite. Series of laboratory tests were conducted to determine the specific gravity, Atterberg limits, compaction, unconfined compressive strength and permeability characteristics of the clay and bentonite for varying proportion of sawdust application. Generally, increasing percentage of sawdust caused a reduction in its specific gravity, maximum dry unit weight and unconfined compressive strength, while it caused an increase in the optimum moisture content and permeability of the modified clay and bentonite. The clay and bentonite both have sufficiently low permeability that satisfies the hydraulic conductivity requirement for use as clay liners. Eight percent (8%) sawdust application to a clay having similar properties as that of this study is recommended as an economic way of modifying it – with the potential of improving its adsorbent property - for use in landfill liner system in order to contain toxic substances from leaching from landfills, thereby protecting the environment and public health.

• Journal Article Type: Article
• Acceptance Date: Nov 20, 2017
• Publication Date: Nov 30, 2017
• Deposit Date: Nov 30, 2017
• Publicly Available Date: Dec 4, 2017
• Journal: Acta Geotechnica Slovenica
• Print ISSN: 1854-0171
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 2
• Pages: 47-56
• Keywords: geotechnical properties, hydraulic barrier, landfill, construction, soil improvement, sustainability
• Public URL: https://uwe-repository.worktribe.com/output/901022
• Publisher URL: http://fgserver3.fg.um.si/journal-ags/2017-2/article-4.asp
• Contract Date: Nov 30, 2017