Hydro-mechanical performance of lime-treated heavy clay incorporating Athel leaves powder

Dried Athel leaves (DAL) are abundant agricultural waste that may have a detrimental effect on the environment due to improper disposal. The current paper is aimed at investigating the incorporation of DAL into lime treatment of heavy clays, presenting a novel sustainable waste management strategy. To the best of the authors’ knowledge, this topic has not been investigated in the literature. The experimental programme is designed to thoroughly assess its effects on the hydro-mechanical properties of lime-treated clay in particular strength gain, swelling pressure and permeability. Tests were conducted on the specimens treated with different ratios of lime and DAL and cured under two different temperatures (i.e. 20 and 40 °C) for various periods. Moreover, microstructural analysis was undertaken to support the results. The results indicated that adding 2% DAL to lime-treated clay specimens cured at 20 °C for 3 months remarkably increased unconfined compressive strength by about 68% compared with those attained on lime-treated clay. Stress-strain relationships suggested that the specimens modified by DAL exhibited an enhanced ductile behaviour. Moreover, the incorporation of 2% DAL further reduced clay swelling pressure by 25% compared with those treated by lime only, resulting in a total swelling pressure reduction of 93.6% compared with that recorded on untreated specimens. Permeability enhancement in the specimens treated with lime and DAL was also observed and supported by the morphological analysis. The comprehensive experimental results confirmed the suitability of using DAL as an efficient enhancer to lime-treated clay. The research outcomes can provide valuable insights into the feasibility of DAL as an eco-friendly additive for improving geotechnical engineering practises.