Probabilistic service life of RC structures under carbonation

The service life of reinforced concrete structures is assessed for carbonation environments using mathematical models based on different tests: carbonation test-based modelling and air permeability test-based modelling. The study includes experimental testing of five concrete mixes with respect to compressive strength, accelerated carbonation and air permeability with different types of cement, in order to assess the models using probabilistic calculus. Both mathematical models are part of the Portuguese National Annex to the European standard EN 206 for the estimation of design service life. Engineers have the option of choosing which of the two models to use, which means that using either model should produce similar results. The design service life results show that the two models do not converge. The different principle of each test – accelerated carbonation and air permeability – and their different characteristics regarding the various parameters of the modelling equations are some of the aspects discussed.