Temperature-Induced Effect of Climate Change on Natural Carbonation of Concrete Structures

Major cities worldwide are densely built with concrete structures. Moreover, urban infrastructures partly cause, and are in return adversely impacted by, the urban heat island (UHI) effect that elevates localized temperature, further to the rise caused by the climate change-induced (CCI) impact of CO2 emissions. While the influence of temperature on carbonation is generally well estab-lished based on experimental research, there are hardly any analyt-ical engineering methods specifically for evaluating temperature effect on natural carbonation. In the present study, an equation referred to as the temperature correction factor (TCF) submodel, capable of accounting for temperature effect on natural carbon-ation, was nested into the natural carbonation prediction (NCP) model, then used to conduct the evaluation. The second aspect of the present study was employment of the TCF submodel for evaluation of CCI temperature rise on natural carbonation. The scope of evaluation covered 130 selected major cities, geographically located globally and strategically represen-tative of the diverse climate regions worldwide. It was found that tropical climate regions exhibit a more significant increase in CCI carbonation progression compared to that of temperate regions. For structural concretes of normal to moderate strengths, CCI carbonation increases from 34 to 46% in tropical regions and by as low as 9.43/0% in cold/subpolar temperate regions. The silver bullet solution to CCI adverse effects is the use of high-strength concretes, which is a conundrum as this measure undermines or negates sustainability principles. Evidently, the projected CCI global temperature rise significantly increases concrete carbon-ation in major climate zones. Research is needed into the develop-ment of counter measures and design provisions for climate resil-ience of concrete structures.