Service life of RC structures: Carbonation induced corrosion. Prescriptive vs. performance-based methodologies

For the last 30 years research projects have been carried out to estimate the service life of RC structures subjected to environmental aggression, based on time-dependent models. These research efforts resulted in the implementation of performance-based methodologies in guide documents [1] and European and national standards. However, the prescriptive methodologies are currently used in most cases. This paper aims to study the convergence of prescriptive- and performance-based methodologies as regards carbonation induced corrosion. An experimental work was carried out to determine the performance properties of prescribed concrete compositions, whose test results were included in the mathematical models of the performance-based specifications. Both safety factor and probabilistic approaches were used to estimate the service life periods of each composition being compared to the target periods defined in the prescriptive specification. The results show that the convergence between the two methodologies still needs to be improved.