Influence of quality control of concrete on structural reliability: assessment using a Bayesian approach

Quality inspection plays an important role in the production process of concrete, as it inherently stimulates producers for obtaining a higher performance with respect to the investigated properties. In case of the conformity assessment of concrete compressive strength, the concrete strength distribution is filtered due to the rejection or acceptance of certain batches and this filter effect can be quantified using Bayesian updating techniques. As a consequence of the filter effect, conformity control has a positive influence on the structural reliability of concrete structures. This filter effect can be quantified by using an approximation method as developed herein or also by using classical FORM/SORM techniques. In order to illustrate the influence of conformity control on structural reliability, concrete elements (columns and beams) which are designed according to the Eurocodes, are analysed considering basic limit state equations, i.e. for compression and bending. Moreover, the influence of the reinforcement ratio and the load ratio on the filter effect is investigated. Numerical analyses reveal that the filter effect may positively influence especially reliability of lightly reinforced concrete members exposed to compression. It appears that it has a minor effect where reinforcement properties govern failure.