Influence of Omani Sarooj on plasticity and california bearing ratio of expansive soil

Abstract. Expansive soils have extreme swelling and shrinking responses to changes in moisture content, hence, there is need for their stabilisation prior to construction usage. Sarooj is a traditional pozzolan produced locally in Oman which has been used as a cementing material for centuries. Sarooj is a sustainable material, sourced locally with lower production energy requirement, lower CO2 emission, and proven durability. This research investigates the impacts of Sarooj on the plasticity and California Bearing Ratio (CBR) of expansive soil obtained from Al Murtafa’a area, Muscat, Oman. The expansive soil was mixed with 3, 6, 9, 12, & 15 Sarooj, after which Atterberg limits and CBR tests were carried out on the soil mixes. The expansive soil was classified as well-graded sand (SW), and A-3 (0) based on USCS and AASHTO classifications, respectively. The optimal value of plastic limit is 6% Sarooj addition, and the AASHTO classification changes to A-2-4 (0) at the same mix. The CBR values increased with the increasing percentages of Sarooj due to structural changes and the pozzolanic reactivity within the mix. With reduced plasticity, increased strength and stability, Sarooj is a viable and sustainable alternative for the stabilisation of expansive soil.