Progress on Carbon Sequestration Technologies for the Full Life-cycle of Concrete
The carbon emissions generated by concrete preparation currently account for 28％of the total carbon release of the construction industry.The carbon sequestration technologies have become the key to achieving the"dual carbon"goals.Concrete carbon sequestration technologies refer to the utilization of carbonization reactions between CO2 and alkaline metal ions(such as Ca2+and Mg2+)or hydration products in concrete pore solutions generating stable carbonates to achieve the purpose of carbon immobilization.Carbonization reactions can affect concretes from the perspectives of characteristics such as pore solution,pore structure,and hydration products,thereby influencing the mechanical properties and durability of concrete.This paper summarizes the carbon sequestration technologies of concrete throughout its full life-cycle(mixing,curing,servicing,and secondary utilization),and systematically discusses the carbonization mechanism,technical characteristics,and storage potential of different carbon sequestration technologies.It has been clarified that injecting CO2 during mixing can promote the carbonization of concrete,but consumes energy and causes additional carbon emissions.Carbonization curing can improve the early strength of concrete,but the dense carbonization products limit the further development of carbonization.The carbonization of servicing concretes does not require human intervention and has great potential for carbon sequestration,but its process is relatively sluggish.The carbonization during the secondary utilization stage can not only achieve CO2 storage,but also improve the quality of aggregates.It is suggested that optimizing existing technologies and introducing new materials and structural forms can improve the CO2 immobilzation efficiency of concrete throughout its full life-cycle.
万方数据
维普
