Structural reliability of eccentrically-loaded sections in RC columns made of recycled-aggregate concrete

The results of experimental and theoretical research on the structural use of concrete manufactured with recycled aggregates are reported. In particular the statistical properties of concrete compressive strength have been studied using a sizable number of samples made with different percentages of recycled aggregates. On the basis of these experimental results a theoretical investigation has been carried out to evaluate the influence of the quality and quantity of recycled aggregates on the structural reliability of RC elements. A methodology for the calibration of the partial safety coefficient to be used with these concretes has been applied, taking as reference the results of Level-2 reliability analysis. The results obtained by means of a parametric experiment allows us to underline that the use of recycled aggregates in structural concrete can be made – as a rule – even with the complete replacement of the natural coarse aggregates but requires more strict design procedures to ensure the same structural reliability as conventional concrete.