Carbonation modeling analysis on carbonation behavior of sand autoclaved aerated concrete

Carbonation could not be ignored because of the significant deterioration of mechanical property and durability of sand autoclaved aerated concrete (SAAC). A better understanding and quantification are necessary for maintaining and repairing the existing structures of SAAC. A practicable mathematical model based on the Fick's first law was established, which was evaluated by the data of accelerated carbonation experiment. Carbonation behavior was studied by means of phenolphthalein test, SEM and XRD. Because the tobermorite generated by hydration gradually transformed into calcite, the compressive strength of samples showed an obvious decline with carbonation depth increased. Furthermore, the experimental date of B05 bulk density class SAAC samples and the calculated values of model have shown good agreements.