Influential factors on concrete carbonation-a review

After water, concrete is the most widely used substance on the planet. Cementitious materials carbonation is an inevitable process through which concrete compositions react with carbon dioxide. Carbonation leads to rebar corrosion in reinforced concrete (RC) structures which reduces the structures' longevity. This process increases cement production due to the repair and replacement which brings about more carbon dioxide emission. On the other hand, plain concrete could be one of the most potential materials in terms of CO2 storage. Therefore, understanding concrete carbonation and the influential parameters on its carbonation is significant. Identifying the effective parameters help engineers increase RC structures' carbonation resistance and increase plain concrete capacity as a carbon capture source which could be both cost-effective and environmentally friendly. In this review, an attempt has been made to summarize the present-day knowledge considering the cementitious materials' carbonation and point out the areas that need more research to be conducted. Influential factors have been categorized comprehensively, to do so. Affecting factors have been explained in three parts, containing subsets. Environmental conditions, concrete characteristics, and construction operation effects have been reviewed. Furthermore, concrete carbonation mathematical models proposed by different researchers have been examined to investigate influential parameters in the models and their precision in prediction.