The Effect of Mechanical Load on Carbonation of Concrete: Discussion on Test Methods and Results

Abstract

Carbonation of concrete, consuming Ca(OH)2 and lowering concrete alkalinity, will lead to reinforcement corrosion and therefore is one of the major causes of concrete deterioration. Most research mainly focuses on the carbonation of concrete without mechanical load. However, concrete structures will bear load in practice, which has a significant influence on CO2 transport and carbonation rate. So, studies on carbonation in combination with mechanical load are of great importance for optimizing service life prediction models. In this review paper, it is discussed how imposed load affects the carbonation of concrete and how a dedicated experimental setup is achieved in the lab. The advantages and disadvantages of existing devices are discussed in terms of specimen size, loading frame, method for applying load and stress compensation. Finally, changes in cracks and pore structure induced by compressive loads at different levels are analyzed with respect to gas permeability and carbonation depth.