Compaction characteristics of Bangkok clay stabilized using rice husk ash, bottom ash, and lime

Abstract

Amount of waste is becoming increasingly undesirable as human population increases day by day. For this reason, recycling wastes produced in different industries and thus lowering their quantities is one of the main focuses for researchers. Soil stabilization using waste by-products especially in road projects that require large amount of earth materials are currently popular and the successful utilization of these wastes can have positive impact on the environment. This can also reduce the construction costs significantly. Bangkok Clay is a well-known soil in Thailand that can possess poor engineering properties and hence there is a need for its improvement. Among all different kinds of waste, rice husk ash (RHA) and bottom ash (BA) are among the cheap materials that are produced in high volumes annually in Thailand and have the potential to be considered as replacement for earth materials. Lime has also been used in this study as common traditional binder in clayey soils that produces the cementitious materials via pozzolanic reaction with materials that are rich in silica and alumina. One of the main steps of construction in road projects is the compaction of stabilized materials which requires the preliminary collection of data from lab performed compaction tests. In this paper, the compaction characteristics of RHA- and BA-Bangkok clay mixtures with lime as a binder were studied. The results show that the MDD reduces and OMC rises with respect to increase in the ash content. Furthermore, the mix designs with RHA are more sensitive to the ash content. Bottom ash mix designs show higher MDD than rice husk ash-soil mixtures and have more potential to be used in road projects based on the compaction characteristics.