TTI Associate Research Engineer Edith Arambula’s National Cooperative Highway Research Program project on evaluating the use of recycling agents was recently featured in an article for Asphalt Pavement. Taking RAP to the Max examines the barriers that prevent the use of reclaimed asphalt pavement (RAP), which is stockpiled throughout the country, and what can be done to overcome these barriers.
According to Arambula, the extent of binder availability depends on how aged the RAP is, which is a function of climatic conditions and mix temperature. Reduced binder availability must be accounted for during mix design, and can often be compensated for through higher dosages of recycling agent or virgin asphalt binder. But too much recycling agent – or simply the wrong agent – can be ineffective, underscoring the need for thorough analysis.