Structural Performance of Modified Warm Mix Asphalt Block Pavements Using a Highway Accelerated Loading Instrument

Rutting and deflection significantly deteriorate pavement durability and safety, requiring innovative strategies to boost structural performance and sustainability. This study investigates the structural stability of modified Warm Mix Asphalt (WMA) block pavements by subjecting them to controlled, accelerated loading using a Highway Accelerated Loading Instrument (HALI). This research also investigates the combined use of Waste Cooking Oil (WCO), Coal Bottom Ash (CBA), and ZycoTherm-SP2 (ZT-SP2) as binder modifiers in WMA for block pavement applications. The modifiers were blended with 60/70 penetration-grade bitumen to improve binder qualities. The modified mixtures were then used to produce WMA blocks with thicknesses of 70 mm, 80 mm, and 90 mm, laid in a stretcher bond pattern with joint widths of 0 mm and 2 mm. Advanced testing methodologies, such as material characterization, rut depth and deflection behavior, surface deformation monitoring, and HALI, provide insights into pavement deterioration mechanisms. The results show that the optimal modifier combination of 0.1% ZT-SP2, 4% WCO, and 5% CBA achieved the best performance, improving rutting resistance and structural stability. The minimum mean rut depths for 90 mm blocks were 5.55 mm (modified) and 5.49 mm (control). The findings demonstrate that the rutting resistance and structural stability are greatly improved in WMA block pavements incorporating binder modifiers. This makes them a sustainable choice for long-lasting pavement construction in practical applications.