Resonant column testing on Portland cement concrete containing recycled asphalt pavement (RAP) aggregates

This study deals with material properties of Portland cement concrete (PCC) made with aggregate that is replaced with recycled asphalt pavement (RAP). A series of PCC mixtures were produced and tested in uniaxial compression using RAP aggregate as substitute of fine and coarse natural aggregate. The main variable was the percentage content by weight of RAP aggregates in the concrete mixture. Both fresh and hardened properties of concrete were examined. Moreover, a relatively new non-destructive technique (free-free resonant column - FFRC) was used to measure concrete's elastic modulus. The experimental results indicate that the compressive strength and the elastic modulus decrease with increasing RAP aggregate replacement, while all mixtures containing RAP aggregates remain workable. Additionally, the replacement of fine natural aggregates has a more pronounced effect on the examined properties. Finally, the FFRC can provide good estimation of elastic modulus.