Utilization of CO2 into recycled construction materials: A systematic literature review

Study on sustainable technology of construction waste in carbon neutrality: concrete decarbonization in Hong Kong

“…Cement can be used to recycle a variety of building materials, whether for field applications or research in a laboratory. Building demolition debris may be recycled as cement additives and aggregates, enabling carbonization to take part in recycling [24]. In cement-based materials, such as concrete, during the setting hardening process, the hydration of the main components of cement clinker, C2S and C3S, produces Ca(OH) 2 , abbreviated as CH and calcium silicate hydrate (C-S-H), as shown in Equations ( 1) and ( 2) from A reaction engineering approach to the problem of concrete carbonation.…”

“…However, the expensive equipment needed for the carbonization process may result in higher prices overall and it is important to take into account that using materials from recycled sources is limited to roads and pavements, while not to buildings with higher requirements for material quality. Extending the scope of uses is thought to call for technical advancement to enhance the functionality of concrete materials [24]: Recycled lump/Aggregate Concrete (RLAC) is a potential and improved solid waste recovery method based on RAC and is the second generation of RLC. It uses both demolished concrete blocks DCL and RA [26].…”

“…The thermochemical conversion of organic materials produces pyrolysis gas and carbonaceous byproducts in solid form. This by-product, called BC, is a green material that has recently gained widespread recognition as an alternative to cement as well as a manufacturing additive for cement-based construction materials [24].…”

“…The use of carbon dioxide can also play an indispensable role in expanding the range RAC of applications [24]. In the context of carbon neutrality, carbon sequestration of renewable waste concrete is an inevitable trend, so it is necessary to find the opportunities from LCA concrete industry.…”

“…The idea behind using CO 2 to pre-treat recycled concrete aggregate (RCA) is to have CO 2 interact with the glue on the RCA. The paste's capacity is increased by the resultant CaCO 3 and the gel of silica, which raises RCA's density and lowers porosity [24]. CO 2 concrete alleviates these problems by carbonizing RAs, reducing CO 2 emissions, reusing crushed masonry materials, and preserving virgin aggregates.…”