2015 CSCE Annual Conference Regina - Building on our Growth Opportunities Conference
Mr. Ahmed El-baghdadi, Lafarge Canada Inc. (Presenter)
Sustainable development is a global ambition, and arguably the innovative key to future development. To address the need for proper disposal of concrete rubble, coupled with a growing scarcity of high quality virgin aggregates near urban centers, the recycling of hardened concrete into aggregate for new concrete production has attracted much attention. This paper summarizes the results of one-year experimental study on Class C2-32 concrete pavements. 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. Evaluation was performed by testing fresh, hardened and durability properties. 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. The results of the field trial are presented in this paper and monitoring is still on-going. In addition, professional contractors have commented on the ease of placement of RCA concrete. The success of this pilot project paved the way for further implementation of RCA in various new concrete applications whilst promoting sustainable growth.
AbdurahmanLotfy, Ph.D., P.Eng.
Regional Manager, New Products Development, Innovation & Commercialization, Lafarge, Toronto, ON