Quantifying Partially-Carbonated Profiles of Concrete with Low Water/Binder Ratio Exposed to Natural Carbonation

Thermo-gravimetric analysis (TGA) and Infrared Spectrum (IR) analysis were adopted to quantify the partially-carbonated profiles of concrete segment exposed to long-time natural carbonation. The results showed that the residual Ca(OH)2 content could be calculated by TGA, and the CaCO3 content formed by carbonation could also be quantified by IR. Thus the partial-carbonation profile illustrated by residual Ca(OH)2 distribution was lower than that by CaCO3 distribution, which indicates Ca(OH)2 and C-S-H gel were carbonated. Furthermore, the carbonation degree of concrete segment was lower than that of specimen because of dimension effect, which suggested that the small specimen could be used to assess carbonation related durability of concrete structures with good reliability.