ONE-YEAR PERFORMANCE EVALUATION OF MUNICIPAL CONCRETE SIDEWALKS USING COARSE AND FINE RECYCLED CONCRETE AGGREGATE

摘要

This paper summarizes the results of an experimental study on Class C2-32 concrete pavements (as specified by the Canadian Standards Association in CSA A.23.1) for an air-entrained sidewalk mixture. Results are reported with respect to mechanical properties and durability aspects of recycled aggregate concrete, compared to its conventional virgin aggregate equivalent. The impacts of replacing virgin aggregate with Recycled Concrete Aggregate (RCA) are discussed in this paper. Mixes were evaluated with replacements of coarse aggregate up to 30% (by volume) and with 20% replacement of both fine and coarse aggregate. Overall performance of recycled coarse aggregate in new concrete was found to be equivalent to that of conventional concrete. Fresh and hardened properties of mixes incorporating coarse recycled aggregate exhibited equivalent performance to the benchmark design, while mixes incorporating the full granular RCA were within acceptable limits, showing a minor decrease in flexural strength and increased susceptibility to salt scaling. Mixes were first evaluated in a laboratory setting prior to implementation in a municipal commercial field trial which continues to display positive performance after an initial year of exposure.