Optimization of glass debris in the treatment of swelling clay soils using recycled materials for sustainable road engineering.

This study focuses on the valorization of glass waste in the field of geotechnics, particularly for the reinforcement of clay soils used in road construction. Glass waste, produced in large quantities, represents a potentially sustainable resource. The experimental work involves incorporating ground glass (particle size < 80 µm) into clay soils in order to evaluate its effects on their mechanical properties. The addition of 30% glass reduces the plasticity index from 28 to 15%, indicating a decrease in water sensitivity. The internal friction angle increases from 11° to 25°, highlighting a significant improvement in shear strength. CBR tests show an increase in bearing capacity, supporting the feasibility of its use in road embankments. XRD analyses reveal mineralogical changes due to the presence of glass, while infrared spectroscopy confirms the existence of amorphous phases. The optimum dry density increases, indicating better compaction. Moreover, oedometer tests show a reduction in swelling and settlement indices. In summary, the incorporation of glass improves the stability and durability of clay soils. This approach represents an ecological and economical solution while contributing to the sustainable management of glass waste.