Strength and Microstructural Behavior of Expansive Soil Treated with Limed Leather Waste Ash

Abstract

Expansive clays are one of the most widely found soil type across the globe known for their low strength behavior. A number of studies have been conducted in the past few decades to stabilize such soils using various additives. The traditional stabilizers such as cement and lime not only prove quite costly due to their high industrial demands but also result in exhaustion of the available natural resources. This study is based on admixture of a waste originating from leather industry known as limed leather waste which can be utilized as a potential stabilizer and strength enhancer for expansive clays at the construction sites as a replacement to conventional additives. The utilization of the waste besides treating the problematic soil will also solve the dumping issue of the waste itself and will reduce the environmental hazards. It is found from the study that the waste when used in the ash form is capable of improving the compaction and strength characteristics of the expansive soil substantially. A comprehensive increase in soil strength is also achieved through curing. The SEM results are used to explain the microstructural changes in the soil and agglomeration and generation of silicate gel compounds responsible for increase in strength of the soil-ash mixture.

Road Pavement Thickness and Construction Depth Optimization Using Treated and Untreated Artificially-Synthesized Expansive Road Subgrade Materials with Varying Plasticity Index

“…Microstructural properties of materials can be determined in the laboratory by conducting a scanning electron microscopy (SEM) analysis, energy dispersive X-ray (EDX) analysis, radar detection, or a Mises strain test, among others [2]. A study conducted by [51] shows the SEM analysis results, which showed a high C-S-H gel development, resulting in high strength after adding 6% of limited leather waste ash (LLWA) in a mix. EDX patterns showed a high formation of calcium silicate hydrate (C-S-H) gel after 28 days when the expansive soil was stabilized or treated with 20% GGBS [52].…”