Durability Properties of Pavement Quality Concrete Containing Fine RAP

In the present study, the potential of supplementary cementitious materials such as silica fume (SF), fly ash (FA), and sugarcane bagasse ash (SCBG) for enhancing the durability properties of pavement quality concrete (PQC) mixes containing 75 % fine reclaimed asphalt pavement (75RAP) is assessed. Different physical and durability properties such as water absorption, total permeable voids, initial rate, secondary rate and coefficient of water absorption, and performance in sulfate and chloride-rich environments were evaluated. It was found that the ASTM recommended temperature of 110 ± 5°C for evaluating water absorption and permeable voids should be changed to 48 ± 2°C to prevent the melting of asphalt present in RAP. Similarly, the duration for completely drying the specimens shall be at least eight days. It was observed that incorporation of fine RAP could compromise with the durability of the PQC mixes significantly. Inclusions of all the considered admixtures (except SF) were found to have an insignificant effect on the modulus of rupture, however, significant enhancement in the durability properties of 75RAP mix was observed (except SCBG). The blending of 15 % FA with 10 % SF was found to enhance the durability performance of 75RAP mix better than the mix containing natural aggregates.