Carbonation in concrete infrastructure in the context of global climate change – Part 1: Experimental results and model development

There is nearly unanimous consensus amongst scientists that increasing greenhouse gas emissions, including CO2 generated by human activity, are effecting the Earth’s climate. Increasing atmospheric CO2 emissions will likely increase the rates of carbonation in reinforced concrete structures. However, there is a lack of reliable models to predict the depth of carbonation as a function of time.To address this deficiency, a numerical model involving simultaneous solution of the transient diffusion and reaction equations of CO2 and Ca(OH)2 was developed. The model successfully includes the effects of variations in various properties such as porosity, humidity, temperature, atmospheric CO2 concentrations and chemical reaction rates.The applicability of the model was confirmed after calibration using data from accelerated carbonation experiments, and the model is used to evaluate the possible effects of climate change by inputting various future climate scenarios in Part 2.