Stabilization of Batu Pahat Peat by Using Rice Husk Ash (RHA)

Abstract

Malaysia possesses the distinction of being the ninth biggest expanse of peat soil land globally, hence encountering significant geotechnical challenges characterised by elevated moisture content, substantial organic composition, diminished shear strength, and reduced bearing capacity. The objective of this study is to investigate the fundamental geotechnical characteristics and strength of Batu Pahat peat that has been stabilised using Ordinary Portland Cement (OPC) and Rice Husk Ash (RHA). The application of Ordinary Portland Cement (OPC) in the process of peat stabilisation has the potential to enhance the mechanical properties and strength of the soil. Nevertheless, the extensive utilisation of cement might result in environmental degradation. Therefore, it is imperative to consider the incorporation of agricultural waste by-products as a partial substitute for cement. Hence, the objective of this research is to employ Rice Husk Ash (RHA) as a supplementary material in cementitious systems. An experimental investigation was undertaken to determine the ideal mix ratio by replacing cement with rice husk ash (RHA) in the range of 5% to 20%. The findings indicate that the peat under investigation can be classified as a hemic peat variety characterised by a high level of acidity. The experimental findings indicated that the peat treated with a 5% concentration of rice husk ash (RHA) (referred to as C95 RHA5) exhibited the maximum Unconfined Compressive Strength (UCS) value of 262 kN/m2. To validate the findings of the Unconfined Compressive Strength (UCS) test, an additional analysis was performed using the Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) technique. This examination aimed to confirm the presence of calcium, which serves as evidence for the observed improvement in strength. In conclusion, it can be inferred that the utilisation of RHA as a substitute for cement at a proportion of 5% exhibits potential for application in Hemic peat.