Effect of Sawdust Powder on the Geotechnical Properties of a Clayey

Abstract

Civil engineers avoid expansive clayey soils in their projects because of the issues and additional expenses caused by volume changes when moisture levels fluctuate. Although techniques exist to enhance their engineering characteristics, these methods are typically costly and environmentally detrimental. These factors, coupled with the increasing shortage of suitable construction soils, have prompted geotechnical researchers to explore recycled materials as soil-reinforcement additives, aiming for a more eco-friendly and economically viable approach. In this context, utilizing certain biowaste to improve soil engineering properties has emerged as an ecologically acceptable geotechnical solution. Sawdust, a globally abundant wood industry by-product, is one such biomaterial. This study presents findings on how the addition of sawdust affects the engineering properties of highly clayey soils. This study investigated the changes in the plasticity, specific gravity, permeability, compaction, and unconfined compressive strength of CH-classified clayey soil (Unified Soil Classification System) with varying percentages (0.0, 1.5, 3.0, 4.5, 6.0, 7.5, 9.0, and 10.5%) of oak sawdust (Tabebuia Rosea). The results indicate that increasing the sawdust percentage leads to decreased plasticity, specific gravity, maximum dry unit weight, and unconfined compressive strength while simultaneously increasing the optimum moisture content and permeability.