Potential of Limestone Calcined Clay Cement (LC3) in soil stabilization for application in roads and pavements construction

Clay soil is associated with geotechnical problems of swelling and shrinkage, which causes deformations on structures. Ordinary Portland Cement (OPC) which is the most common stabilizing agent for clay soils, remains unaffordable in most developing countries, and its production also contributes about 8 % of global anthropogenic CO2 emissions. The present study aimed to investigate the effect of Limestone Calcined Clay Cement (LC3) on the stabilization of clay soils for applications in road construction. Clay soil was mixed with quarry dust to reduce the clay content and save cement. The mixture was stabilized using LC3 and OPC separately in proportions of 1 %, 3 % and 5 %. The effect of stabilizer dosage on the performance of clay soil was studied by monitoring the changes in Atterberg limits, Proctor test and soaked California Bearing Ratio (CBR). The mineralogical and microstructural investigation was carried out using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA). Plasticity index (PI), linear shrinkage (LS), and optimal moisture content (OMC) of stabilized soil was found to decrease with increase in the dosage of LC3 and OPC. The Maximum Dry Density (MDD) and soaked CBR increased with addition of both LC3 and OPC. Formation of calcium silicate hydrate (C-S-H) in both LC3 and OPC stabilized clay soil, as well as formation of Hemicarboaluminate in LC3 stabilized clay soil was responsible for improved properties of the stabilized soil. The performance of LC3 was found to be comparable to that of OPC, at optimum cement ratio of 5 %.