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Title: A More Sustainable Unshrinkable Fill

Author(s): Maryam Kolahdoozan, Medhat H. Shehata, Mohamed Lachemi, Hannah C. Schell, Stephen Senior, and Carole Anne MacDonald

Publication: Concrete International

Volume: 36

Issue: 9

Appears on pages(s): 33-37

Keywords: U-fill, strength, abrasion, hardening time


Date: 9/1/2014

Unshrinkable fill is a type of controlled low strength material (CLSM) used in lieu of traditional backfill. While it is normally produced using aggregates derived from bedrock, gravel, or natural sand sources, the low maximum strength requirement indicates that alternative materials could be used. The research described in this article investigates the use of reclaimed concrete aggregate (RCA) as a sustainable and economical alternative to the newly extracted materials used in U-fill mixtures. The RCA was produced by crushing returned ready mixed concrete that had been allowed to harden.