Improving the behaviour of sand with ceramic additives for sustainable ground engineering

This study investigates the effectiveness of waste ceramic powder as a sustainable additive for improving the geotechnical behaviour of poorly graded sandy soils. Ceramic waste was mixed with sand at 5%, 10%, and 15% by dry weight, and its influence on density, permeability, and shear strength was evaluated through laboratory testing and numerical modelling. Results indicate a significant improvement in mechanical properties: the internal friction angle increased from 27° for untreated sand to 40.6° at 15% ceramic content, while apparent cohesion increased from 0 to 15.4 kPa. Permeability decreased markedly from 0.115 to 0.0356 m/s due to the micro-filler effect of fine ceramic particles. Maximum dry density increased from 1.553 to 1.904 g/cm³, indicating improved compaction behaviour. Finite element analyses using PLAXIS 8.6 confirmed the experimental findings, showing reduced static settlement (from 131 to 77 mm) and lower seismic-induced displacements under Kocaeli, Kobe, and Chi-Chi earthquake motions. The results demonstrate that waste ceramic powder is a low-carbon, cost-effective alternative for sandy soil stabilisation, contributing to sustainable ground engineering and circular material reuse.