Sustainable stabilization of expansive soils using burned olive waste ash (BOWA) and lime for pavement construction

Abstract. In geotechnical engineering, soil stabilization is a common practice in which additives enhance soil properties. This is especially important for highly expansive soils, which can cause cracking and instability in structures built on them. The present study investigated using a combination of burned olive waste ash (BOWA) and hydrated lime to stabilize highly expansive soil. A range of percentages for both additives was tested to identify the optimal mixture of BOWA and lime. BOWA percentages of 10%, 20%, and 30% were tested, while lime percentages of 4%, 6%, and 8% were also tested. The study demonstrated the effectiveness of using BOWA and lime as additives for stabilizing highly expansive soil. The results showed that adding BOWA and lime notably decreased the expansive natural soil's swelling potential, plasticity index, and linear shrinkage. Furthermore, the UCS and CBR values of the stabilized soil showed a significant improvement. The results showed that BOWA could be a suitable stabilization agent for the subgrade and base layers in pavement construction. Utilizing BOWA as an additive to the lime-stabilized soil offers environmental and cost benefits.