Numerical analysis of the effect of coarse aggregate distribution on concrete carbonation

This paper presents the results of a mesoscopic numerical simulation of the influence of the distribution of coarse aggregate on concrete carbonation. In the study, concrete was considered as a two-phase composite material that consisted of cement mortar and coarse aggregate. The numerical simulation results indicate that the concrete carbonation depth decreased and its variation increased with the increased use of coarse aggregates or the increased fraction of relatively small aggregates. It was also found that, for the same coarse aggregate distribution, the variation of the concrete carbonation depth in the core area of the concrete increased with increased penetration depth of carbon dioxide (CO2). On the other hand, such variation in the boundary layers became less significant, since the coarse aggregate distribution density increased with the distance from the perimeter of the concrete.

► A mesoscopic numerical simulation of concrete carbonation was proposed.
► Variation of carbonation depth increased as smaller aggregates fraction increased.
► Carbonation variations in the core area and the boundary layer were different.
► Carbonation depth decreased as proportion of smaller aggregates increased.