Abstract
Chemical soil stabilisation is an established technique in road construction. However, it is constantly evolving to discover novel treatment agents that reduce environmental impact. Traditional agents such as cement and lime, while effective, have drawbacks in terms of cost and environmental impact compared to novel agents. Furthermore, these two agents are rendered ineffective for certain types of highly plastic soil or when the soil is subjected to frequent drying and wetting cycles. Marls’ complex and variable mechanical behavior makes them difficult to use as backfill materials. In this context, this study aims to investigate the mechanical behavior of local clayey marl stabilised by an unconventional binder made up of recycled eggshell quicklime and natural zeolite. Unconfined compression, Californian Bearing Ratio, and rectilinear shear tests were carried out on samples treated with varying dosages (2, 4, 6, 8, and 10%), eggshell quicklime and natural zeolite proportions, and curing times (7, 28, and 56 days. The results show that adding the eggshell quicklime and natural zeolite binders improved the mechanical properties of the marl. The compressive strength ratios increased by 4 to 11 times, the Immediate Bearing Index (IBI) exceeded 20 and the friction angle (φ) increased until 25°. The addition of zeolite to eggshell quicklime for soil stabilisation appears to have a positive effect on the different parameters studied. The admixture of these two materials represents a promising alternative for stabilising clayey marls, providing a more sustainable and environmentally friendly solution for earthworks.