The research objectives were to investigate the feasibility of using recycled concrete aggregate (RCA) as a base course material in asphalt pavement, to evaluate the physical properties of RCA, and to develop practical and reliable guidelines and specifications. The tasks included literature review, sample collection, laboratory testing, accelerated performance testing and pavement distresses monitoring, falling weight deflectometer (FWD) test, theoretical analysis of pavement, and development of guidelines and specifications for the use of Florida RCA. Three test sections of asphalt pavement were constructed at the University of Central Florida's circular accelerated test track. Two sections of different thicknesses were constructed with RCA base and one section with limerock (LR) base. A total of 362,198 load repetitions were applied to the test sections. This is equal to 811,324 repetitions of the 18-kip (80-kN) equivalent single-axle load. The pavement distresses of rutting, cracking, and settlement were monitored during the course of the performance testing. The FWD test was performed on the pavement test sections to backcalculate the in situ resilient moduli of RCA and LR for theoretical analysis of life expectancy. The findings support the hypothesis that RCA can be used effectively as a base course when appropriate quality control techniques are used. On the basis of the information obtained, a set of specifications for the use of RCA as a base course in flexible pavements was developed.
Samenvatting