Fundamental understanding of carbonation curing and durability of carbonation-cured cement-based composites: A review

Abstract To tackle the rising CO2 concentration in atmosphere, technologies of carbon sequestration are emerging. As one of these technologies, carbonation curing of cement-based composite at early age shows a great potential because its wide application and benefits to provide cement-based composite with enhanced mechanical properties and durability. However, carbonation curing is mostly investigated on lab-scale, due to two main challenges that should be addressed before it can be widely applied for industrial-scale production: (1) CO2 sequestration rate is still low, which is around 20 %–50 % of the theoretical potential because of the limitation of CO2 diffusion into matrix during the carbonation curing; and (2) the effect carbonation curing on the durability of cement-based composites and the underlying mechanisms remains unclear, especially for some critical aspects such as alkali-silica reaction, corrosion, and sulfate attack. Therefore, this paper focuses on discussing: (1) factors affecting CO2 sequestration in cement-based composite during each stage of carbonation curing and the optimization methods of carbonation curing for high CO2 sequestration rate without mitigating mechanical properties and durability, and (2) effects of carbonation curing on different aspects of durability and the corresponding mechanisms. Based on the review, future studies on addressing current challenges are inspired to comprehend and promote the carbon sequestration by carbonation curing of cement-based composites.