Performance of Continuously Reinforced Concrete Pavement Containing Recycled Concrete Aggregate

摘要

This paper presents the performance of continuously reinforced concrete pavement (CRCP) constructed in 1995 that utilized recycled concrete aggregate (RCA) as both coarse and fine aggregates. The project is Houston on a section of IH-10 between Loop 610 W and IH-45. In this project, no virgin aggregates were used. Concerns were raised regarding the performance of CRCP containing RCA. Detailed study was conducted to evaluate concrete material properties containing RCA. The properties of recycled aggregate measured in this study compared with virgin aggregate are consistent with those reported elsewhere: low specific gravity, higher water absorption, sulfate soundness loss, LA abrasion loss, and thermal coefficient. Little variation was observed in the paving operation due to the use of 100 % recycled coarse and fine aggregates. The moisture control of recycled aggregate, especially fine aggregate, is critical in producing consistent and workable concrete. The short-term and long-term performance of the reconstructed CRCP has been excellent, with tight crack widths and little spalling. Between concrete with virgin aggregates and concrete with recycled aggregates, there is no significant difference in thermal coefficient and permeability; however, there are significant differences in modulus of elasticity, compressive and indirect tensile strength, and water absorption. The low modulus of RCA concrete and good bond between recycled coarse aggregates and new mortar appear to be the key ingredients for good pavement performance. After more than 10 years of service under heavy traffic, the CRCP section containing 100% RCA is still providing excellent performance with no single structural distress.