A Preliminary Assessment of SMA Modification Due to Post-Accidents Spills Contamination and Long-Term Tire Wear

This study presents a preliminary investigation into the effects of post-accident contamination and long-term tyre abrasion on Stone Mastic Asphalt (SMA-13) used in highway surface layers. Two pollutants (petrol and electric car coolant) were selected as representative contaminants for hydrocarbon-fuelled and electric vehicles. Both new and artificially aged slabs were subjected to accel-erated polishing using the Harbin Accelerated Polishing Machine, followed by skid resistance test (PTV) and mechanical performance evaluation (ITS). Results revealed that petrol contamination caused severe and non-uniform surface dam-age, confirming the solvent action of hydrocarbons on the binder. The electric coolant produced more uniform wear but temporarily reduced skid resistance under repeated loading. Ageing increased stiffness but reduced ductility, ampli-fying the combined effects of traffic and contamination. These findings highlight the importance of timely contaminant removal and indicate that, in aged pave-ments, surface layer replacement may be required to restore adequate safety and performance.