Proposal for classification of concrete quality based on accelerated carbonation tests

Reinforcement corrosion is a problem affecting the durability of most concrete structures. When concrete is employed without proper care, it may function inadequately as a barrier, allowing aggressive ions or acidic substances in the atmosphere to attack steel rebars. The principal agents responsible for corrosion are carbon dioxide (CO2) and chlorides (Cl-). Most carbonation research is based on accelerated carbonation tests. Thus, there is an important need to evaluate this process, via comparison with samples having undergone natural carbonation. However, as longterm analysis is required, such studies are scarce. This study proposes classifications of concretes regarding carbonation risks, based on carbonation coefficients obtained through accelerated tests (Kacel). An extensive literature review is conducted, compiling Kacel results and their correlations with values of natural carbonation coefficients (Knat). The results provide an improved classification of concretes regarding their resistance to carbonation, which will help researchers and designers to specify the concrete.