Rheological and mechanical characterization of waste PMMA/ATH modified bitumen

Waste composite poly-methyl methacrylate filled with a fine dispersion aluminium trihydrate (PMMA/ATH) and Fischer–Tropsch wax were used as modifying agents for a 70/100 paving grade bitumen employed for road paving. The effect of modifying agent content, primary ageing and long-term oxidative ageing on rheological and mechanical properties of base and modified bitumen were studied. The rutting resistance at high service temperatures was analyzed with oscillatory shear tests and multiple stress creep recovery measurements. Waste PMMA/ATH powder proved suitable for bitumen modification, particularly in combination with wax. Moreover, aluminium trihydrate is a flame retardant material. PMMA/ATH is less susceptible to heat and oxygen, therefore modified bitumen samples show improved viscoelastic and physical characteristics compared to base bitumen at handling and in-service temperatures.