Evaluation of the chloride migration and carbonation coefficients of Belgian ready mixed and precast concrete for a performance-based design

In the design of Belgian concrete structures, durability aspects are currently assessed based on a deemed-to-satisfy approach according to the standards NBN EN 206-1 (2014) and NBN B 15-001 (2012). As this design method hinders innovation, the trend worldwide is to move towards durability-based design of concrete structures. Within the Tetra project "DurOBet", a quantitative method has been developed to implement a performance-based design for durability in Belgium. For the damage mechanisms chloride ingress and carbonation, reference values have been set up in function of the exposure class, cement type, concrete cover, initial chloride content and curing time. The reference values were deduced from available data and additional test results obtained within the "DurOBet" project, using a probabilistic approach. In the study as presented here, twelve ready mixed and precast concrete mixtures were tested and evaluated with regard to their resistance to chloride and CO2 ingress. A comparison was made between the evaluation of their durability based on a deemed-to-satisfy approach and a performance-based approach. It was verified to what extent the actual migration coefficient and carbonation coefficient meet the predefined reference values for the different exposure classes taking into account a design service life of 50 years