Modelling chloride ingress into in-service cracked reinforced concrete structures exposed to de-icing salt environment and climate change: Part 1

The greenhouse gases (GHG), in terms of CO2 emissions, have influenced the climate system by altering the planet’s temperature and relative humidity (RH) patterns creating global warming. These changes in temperature and RH have increased the penetration rate of chloride in existing concrete structures causing an acceleration of degradation processes that have the tendency to influence the serviceability and safety of these structures. There is a flurry of models to predict chloride penetration, however only very limited models aims to predict the chloride concentration profiles as a function of time, temperate and RH in cracked concrete members which is the characteristic of any existing concrete structures. The factors affecting chloride concentration and penetration in concrete are categorized as ‘internal’ (relating to the characteristic material properties such as porosity and crack width) and ‘external’ (relating to the environmental parameters, such as Temperature and RH). The fundamental aim of this research is to develop an integrated deterioration prediction model of chloride concentration and penetration in concrete considering the impacts of variations in the internal and external factors. The model is based on simultaneous solutions of diffusivity of chloride ions and it is validated using the data obtained from accelerated chloride penetration experiments. It is then used to investigate the chloride concentrations in existing concrete structures due to the impact of climate change scenarios based on the IPCC, 2014 and the UKCP'09 climate projections.