Bottom Ash Stabilized Subgrade Soil Admixed with Sugarcane Bagasse Ash

Abstract

AbstractExpansive soils are popularly known as black cotton soils in India. It shows very high swelling and shrinking characteristics. Hence, it becomes necessary to stabilize these soils for infrastructural development such as for the construction of roads. For the purpose of full or partial replacement of traditional stabilizers, recent research in the field of geotechnical engineering focuses more on the use of cheap and locally available industrial wastes as stabilizing agents. In this study, it is aimed to evaluate the possible utilization of industrial wastes like bottom ash (BA) which is a by-product obtained from thermal power plant, effectively in, along with sugarcane bagasse ash (SCBA) as stabilizing agent for a locally available expansive soil. Various engineering property tests like proctor compaction, California Bearing Ratio (CBR), unconfined compressive strength (UCS) and split tensile strength were conducted for soil–SCBA–BA mixes in different proportions. BA was varied from 0 to 40% and SCBA was varied 0–9%. A small amount of cement (3%) was also added to promote pozzolanic reaction. It was observed that the engineering properties of the mixes depend mainly on the amount of BA and SCBA as well as curing period. Microstructural and mineralogical studies were also conducted to check the effectiveness of the proposed stabilizing agent at nano-scale. This experimental investigation suggests the possibility of using BA and SCBA in combined form to get maximum benefits in soil stabilization. By promoting these materials, the number of costly additives like cement and lime can be reduced significantly which will provide an economical and environmental friendly solution.KeywordsSoil stabilizationSugarcane bagasse ash (SCBA)PozzolansBottom ash (BA)