Carbon Emission Evaluation of CO 2 Curing in Vibro-Compacted Precast Concrete Made with Recycled Aggregates

• Published in: Materials Vol. 16; no. 6
• Main Authors: Suescum-Morales, David, Fernández-Ledesma, Enrique, González-Caro, Ágata, Merino-Lechuga, Antonio Manuel, Fernández-Rodríguez, José María, Jiménez, José Ramón
• Format: Journal Article
• Language: English
• Published: Switzerland 18.03.2023
• Subjects: construction and demolition waste; CO2 curing; CO2 sequestration; carbon emission evaluation; waste recycling
• ISSN: 1996-1944; 1996-1944

The objective of the present study was to explore three types of vibro-compacted precast concrete mixtures replacing fine and coarse gravel with a recycled/mixed concrete aggregate (RCA or MCA). The portlandite phase found in RCA and MCA by XRD is a "potential" CO sink. CO curing improved the compressive strength in all the mixtures studied. One tonne of the mixtures studied could be decarbonised after only 7 days of curing 13,604, 36,077 and 24,635 m of air using natural aggregates, RCA or MCA, respectively. The compressive strength obtained, XRD, TGA/DTA and carbon emission evaluation showed that curing longer than 7 days in CO was pointless. The total CO emissions by a mixture using CO curing at 7 days were 221.26, 204.38 and 210.05 kg CO eq/m air using natural aggregates, RCA or MCA, respectively. The findings of this study provide a valuable contribution to carbon emission evaluation of CO curing in vibro-compacted precast concrete with recycled/mixed concrete aggregates (RCA or MCA). The technology proposed in this research facilitates carbon capture and use and guarantees enhanced compressive strength of the concrete samples.