Effect of glass waste powder and date palm seed ash based sustainable cementitious grouts on the performance of semi-flexible pavement

Cement plays a pivotal role in the production of semi-flexible pavement (SFP), however, it contributes to 8 % of global carbon dioxide emissions. Consequently, reducing cement usage in grout production for porous asphalt mixtures is highly desirable to mitigate the overall carbon footprint. Additionally, the substantial generation of agricultural, industrial, and hazardous waste often ends up in environmental disposal without recycling. This research aims to repurpose glass waste powder (GWP) and date palm seed ash (DPSA) as partial substitutes for cement in SFP, aiming to curtail environmental pollution from cement production, decrease costs, and enhance waste and landfill management. Novel cement grouts were formulated by partially replacing Portland cement with GWP and DPSA at varying ratios (10 %, 20 %, and 30 %). These grout blends were assessed for flow characteristics and compressive strength. Furthermore, SFP samples were prepared by integrating 5 % styrene-butadiene-styrene (SBS)-modified bitumen into a porous asphalt structure, subsequently filled with predefined cement grouts. Comparative analysis of compressive strength, Marshall stability, skid resistance, and moisture damage resistance indicated that SFP specimens modified with GWP and DPSA exhibited superior performance over conventional counterparts. Optimal results were achieved with a combination of 20 % GWP and 10 % DPSA replacement ratio, yielding denser microstructure, enhanced skid resistance, and improved adhesion and tensile strength, thereby enhancing overall SFP performance.