Crumb rubber-modified (CRM) asphalt made with the “wet process” has many beneficial properties, including enhanced rut-resistance, greater crack-resistance, and delayed aging (oxidation) compared to virgin asphalt mixtures. However, it requires agitated storage conditions for the CRM binder, and if a pre-blended CRM binder supplier does not exist in the contractor’s region, it requires the use of an asphalt rubber blending unit at the hot mix asphalt (HMA) plant to produce the CRM binder. A new product on the market, Vestenamer, may provide an alternative to both pre-blended CRM binder and blending CRM binder at the HMA plant.

This project will evaluate the performance of CRM asphalt mixtures using Vestenamer materials compared to mixtures made with conventional wet-process CRM binder, polymer-modified binder, and virgin (un-modified) binder. It will involve the exploration of several important mix performance properties of hot mix asphalt (HMA), including:

• Rut resistance
• Fatigue resistance
• Moisture susceptibility
• Resilient modulus