Experimental study on carbonation depths of OPC and PPC concrete by conventional and advanced methods

Abstract

Analysis of carbonation depths in concrete through conventional phenolphthalein indicator method as well as advanced methodologies such as X-ray diffraction analysis (XRDA) and Fourier Transform Infra-Red (FTIR) method is used to evaluate the accurate effect of carbonation on concrete samples. Concrete is carbonated in an acceleration chamber for the experimental process to achieve results in a limited period. Concrete samples have been prepared by using OPC cement and PPC cement at three different water/cement ratios (0.40, 0.45, and 0.50), and retained in a carbonation chamber at fixed parameters. The results of carbonation depths of concrete samples were obtained from advanced methods as well as the conventional phenolphthalein indicator method and analyzed the results. Carbonation depths obtained from advanced methods were nearly double that of results obtained from the conventional method for OPC and PPC concrete. The carbonation depth of concrete samples is increased with an increase in the W/C ratio. The carbonation depth of PPC concrete samples is higher in comparison to OPC concrete obtained by all mentioned three methods. Hence OPC concrete is proposed to use in place of PPC concrete to reduce the risk of carbonation in reinforced concrete structures in the polluted area.