Assessing benefits of pre-soaked recycled concrete aggregate on variably cured concrete

Coarse recycled concrete aggregate (RCA) is a variable material, and that variability can often make it less desirable for usage in concrete infrastructure. One consistent characteristic of RCA however, is a higher absorptive capacity when compared with natural aggregate (NA). Due to this higher absorptivity, there is potential for the RCA to provide some internal curing-like benefits when it is properly prepared prior to batching into concrete. Internal curing involves the entrainment of water in reservoirs within the concrete which is drawn from the reservoirs at a beneficial point of the cement hydration process. Internal curing in concrete has been found to have many benefits including reducing the negative effects of poor external curing. In this research, two types of saturated coarse RCA have been used to study the effects of different curing practices on the performance of the concrete. Particular emphasis has been placed on those properties that are critical for concrete pavement design. Two curing regimes are used in order to better understand the impact of curing practices on saturated RCA concretes. The two RCA sources oppositely affected the compressive strength: RCA 1 increased strength while RCA 2 caused a decrease. Saturated high absorption RCA appeared to provide some benefit in terms of compressive strength loss under poor curing conditions. Both RCA types had similar negative effects on the tensile strength and elastic modulus of the concretes in comparison to natural aggregate. (C) 2017 Elsevier Ltd. All rights reserved.