Clayey soils undergo considerable volumetric changes with moisture variation, ranging from shrinkage to swelling, thereby posing serious challenges for civil engineering projects. Therefore, stabilizing clayey soils is crucial, particularly for road construction. This study investigates the effects of recycled ceramic waste powder (CWP) on the geotechnical behavior of high-plasticity clay (CH) to enhance soil strength and reduce environmental impacts. The research evaluates clay soil properties mixed with CWP at varying percentages (0%, 6%, 12%, 18%, and 24% by dry weight of the soil samples). Laboratory tests were conducted on untreated and CWP-stabilized soils, including Atterberg limits, free swelling (FS), standard Proctor compaction, unconfined compressive strength (UCS), and California bearing ratio (CBR). The results indicate that with increasing percentages of CWP, the index properties, FS, optimum moisture content (OMC), energy absorption capacity, and required pavement thickness decreased up to 24% CWP content. Meanwhile, maximum dry density (MDD), UCS, CBR, and resilient modulus increased up to 12% CWP content, beyond which these properties began to decline. At this optimum CWP content of 12%, MDD increased by 13.01% compared with the untreated CH soil, UCS improved by 39.7%, and the soaked CBR rose from 3% (CH soil) to 19%, representing an approximate 533.3% increase. Microstructure analyses confirmed that 12% CWP treatment enhanced the chemical and microstructural stability of the soil, contributing to the observed improvements in strength. Polynomial regression models demonstrated strong predictive capabilities (R 2 = 0.8815–0.9975), capturing non-linear trends and optimizing CWP content for soil performance. Notably, the correlations between UCS and CBR (R 2 = 0.993) validated the statistical framework for strength estimations. These findings indicate that incorporating CWP improves soil compaction behavior, reduces swell potential, and significantly enhances strength. Accordingly, CWP may serve as a promising low-cost and environmentally friendly stabilizing additive for improving clayey soils in foundation and subgrade applications.
Blayi et al. (Tue,) studied this question.