Using recycled aggregate in concrete is an environmentally friendly solution that preserves the environment and the earth's natural resources. However, the suitability of recycled aggregate for use in structural concrete must be verified. In this research, experimental investigation of concrete containing recycled asphalt pavement (RAP) was conducted in terms of slump, water absorption, density and compressive strength for different concrete mixes. Five concrete mixtures were prepared using crushed RAP as a coarse aggregate at different replacement percentages; 0%, 25%, 50%, 75%, 100% by weight of natural coarse aggregate (NA). The test results showed that good workability was attained for fresh concrete with RAP aggregate and higher RAP replacement revealed higher slump. However, it was found that for 100% RAP replacement, the compressive strength of concrete was reduced by 52% of the control concrete (100% NA). Also, water absorption of concrete was increased when the RAP replacement increased and the percentage of increase of water absorption, as a percentage from the control concrete reached to 17.9% at concrete with 100% RAP. The test results showed that the concrete with 75% RAP was the optimal RAP content in terms of density compared to other concretes with RAP.
Ahmed et al. (Wed,) studied this question.