Empirical modelling of CO2uptake by recycled concrete aggregates under accelerated carbonation conditions

Xiaoliang Fang, Dongxing Xuan, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

75 Citations (Scopus)


In order to assess the potential CO2capture ability of recycled concrete aggregates (RCAs) subjected to accelerated carbonation, an empirical prediction model has been developed in relation to carbonation conditions and the characteristics of RCAs. In this study, two sources of RCAs were used: RCAs from a designed concrete mixture and RCAs obtained from crushing of old laboratory concrete cubes. Two types of carbonation approaches were employed: (A) pressurized carbonation in a chamber with 100% CO2concentration and (B) flow-through carbonation at ambient pressure with different CO2concentrations. Four groups of RCAs particles with sizes of 20–10, 5–10, 2.36–5 and <2.36 mm were then tested and evaluated. It was found that a moderate relative humidity, a CO2concentration higher than 10%, a slight positive pressure or a gas flow rate of >5 L/min were optimal to accelerate the RCAs carbonation. Moreover, the CO2uptake of fine RCAs particles was faster than that of large RCAs particles. The developed model was able to predict the CO2uptake in relation to relative humidity, particle size, carbonation duration and cement content of the RCA under the tested carbonation conditions.
Original languageEnglish
Article number200
JournalMaterials and Structures/Materiaux et Constructions
Issue number4
Publication statusPublished - 1 Aug 2017


  • Accelerated carbonation
  • Carbonation conditions
  • CO uptake 2
  • Recycled concrete aggregates

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)
  • Mechanics of Materials


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