Mechanical Performance of Hot Mix Asphalt Containing Chemically Treated High Siliceous Aggregates

High siliceous aggregates exhibit very poor adhesion with asphalt binder in hot mix asphalt (HMA) and are more likely to fail early before service life. This is because hydroxyl groups on the surface of aggregates make them acidic, which causes moisture-induced damage to HMA. To enhance the moisture resistance and mechanical properties of HMA, either the aggregate surface needs to be modified or additives need to be added to the asphalt binder. The present study tried to evaluate the mechanical properties of HMA made with surface-modified siliceous aggregates. Three aggregates with high silica content (more than 75 percent silica composition) were surface-modified with three different chemicals, namely, hydrated lime, silane coupling agent, and nano-organosilane. HMA mixtures were prepared with two viscosity-grade binders (i.e., VG-30 and VG-40) and two polymer-modified binders (i.e., PMB-40 and PMB-70). The permanent deformation and fatigue cracking performances were evaluated using the cyclic compression test and the indirect tensile fatigue (ITDF) test, respectively. The mechanical performance of HMA with chemical treatment methods was analyzed for compatibility with different binders. As per the Indian Roads Congress (IRC-37:2018), a resilient modulus test conforming to ASTM D4123 (1995) was conducted to measure the resilient modulus of HMA mixtures with treated aggregates so that the results could be used in field sections.