Test of recycled concrete aggregate in accelerated test track

This paper reports the findings of a project on evaluating the performance of recycled concrete aggregate (RCA) for use as a base material under hot mix asphalt pavements and as an aggregate in portland cement concrete pavements. Nine design sections involving hot mix asphalt and portland cement concrete pavements were constructed at the University of Central Florida's Circular Accelerated Test Track to evaluate the performance of the pavement sections made with RCA under actual dual-wheel loading. Laboratory tests performed on concrete specimens made of different percentages of RCA and virgin aggregate (VA) showed that the higher the percentage of RCA material, the lower the compressive, flexural, and tensile strengths. Despite having lower compressive strength than VA concrete, 100% RCA concrete had a compressive strength of 35 MPa (5,070 psi), which was well above the target strength of 25 MPa (3,630 psi). Trenching of the flexible pavement test sections and petrographic examination of the hardened concrete showed that after a simulated life expectancy of 3.04 years for asphalt sections and 4.2 years for concrete sections, RCA has performed at least equally to VA.