Enhancing performance and fuel resistance of modified epoxy asphalt using amine and carboxyl terminated PET co-hardener

In this study, a fuel-resistant modified epoxy asphalt was formulated using a co-hardener containing a commercial amine and carboxyl terminated PET (CTPET). Rheological, physical, mechanical, and fuel-resistance properties were evaluated across various epoxy polymer-to-asphalt ratios. The CTPET co-hardener enables blending with up to 85% epoxy polymer, preserving viscoelastic behaviour comparable to base asphalt. Notably, higher epoxy-to-asphalt ratios enhanced the complex shear modulus, phase angle, rutting resistance, and cohesion bonding. Furthermore, weight loss measurements after immersing the specimens in kerosene at 80°C for 24 h revealed losses of 1.08%, 0.24%, 0.18%, and 0.01% for blends containing 70, 75, 80, and 85 wt% epoxy, respectively, all well below the standard limit of 2%. The material also retained an elongation at break exceeding 1000%. Additionally, the penetration values, softening points, and tensile strengths remained stable before and after immersion, confirming the material’s durability and suitability for fuel-resistant applications.