Qian et al. (2024): Investigations on carbon-sequestration optimization of recycled coarse-aggregate and its effects on concrete performances

Rusheng Qian, Lin Wan-Wendner, Chengqi Yang, Ruze Zhao, Zhibo Ye, Deyu Kong, Yong Zhang IN: Journal of Building Engineering, 90, 109453, https://doi.org/10.1016/j.jobe.2024.109453

Recycled coarse-aggregate (RCA) derived from waste concrete can be re-used for concrete preparation, which is now limited due to its drawbacks such as micro-cracks, high-porosity, and reduced concrete strengths. To remedy these deficiencies, carbon-sequestration was employed to enhance RCA and the conditions were optimized, including the temperature (20 °C–40 °C), pressure (0.1 MPa–0.3 MPa), time (5 h–24 h) and initial water content (25%–75 %). There parameters were optimized based on the orthogonal test with scheme L9(34), which was evaluated based on RCA carbon-sequestration amount as well as its properties. With the optimized parameters, RCA was enhanced as CRCA. Both RCA and CRCA were utilized to fully replace natural coarse-aggregate (NCA) in concrete and concrete basic performances were investigated systematically, including strengths, shrinkage and medium transport properties.