Strength and Durability Properties of Treated Recycled Aggregate Concrete by Soaking and Mechanical Grinding Method: Influence of Processing Technique

Abstract

The use of recycled aggregate (RA) generated from construction and demolition (C&D) waste to produce new concrete would minimize the need for the use of natural aggregate (NA). The authors propose a new hybrid method in the present work by combining presoaking in mild acetic acid followed by mechanical grinding to produce high-quality RA. A total of six different types of treated recycled aggregates (TRAs) [i.e., TRA (0 min), TRA (3 min), TRA (5 min), TRA (7 min), TRA (10 min), and TRA (12 min)] were used to replace NA in an M40 grade control mix to study the influence of TRAs. In this study, various percentages (i.e., 0%, 25%, 50%, 75%, and 100%) of TRAs were used to replace NA in each concrete mix. Experiments were performed to investigate the workability, strength, and durability properties of concrete made with TRAs. Typically, at a 50% replacement level of NA with TRA (7 min), the compressive strength reduced by 7.58%, and the rapid chloride permeability test (RCPT) value increased by 23.74% compared with the control mix. A 50% replacement level of NA with TRA (7 min) is suggested for structural concrete. Based on the present study, 72 h of soaking in mild acetic acid, followed by 7 min of the rotation time, are recommended as an optimum treatment for producing high-quality TRA.