Evaluation of the physical and mechanical behaviour of rammed earth by incorporation of recycled glass

Compacted soil walls provide environmental benefits due to their low impact and embodied energy. Although their mechanical strength is lower than other materials, they meet safety requirements. Current trends promote circular economy solutions, such as waste reuse. This study assesses recycled glass in lime- and cement-stabilized rammed earth as a replacement for natural sand to enhance waste management and soil properties. Ultrasonic inspection confirms increased compressive strength and density, especially in cement-stabilized mixtures. Statistical analysis reveals a direct correlation between crushed glass content and improved properties. The optimal replacement rate is 75% for lime and 100% for cement. The superior performance in cement-stabilized samples is due to a pozzolanic reaction absent in lime mixtures. Both binders show significant reductions in thermal conductivity, improving energy efficiency without compromising structural integrity. Ultrasound proves reliable for predicting compressive strength and stiffness, supporting the viability of this approach. The incorporation of recycled glass in compacted soil offers a sustainable construction alternative, balancing environmental benefits with enhanced mechanical and thermal performance.