ABSTRACT
Durability problems in concrete technology are in many cases resulting from internal deformations due to expanding aggregates (alkali-aggregate reaction) or to corroding steel reinforcement. Significant gradients characterize the associated stress fields. Since specimens with standardized size and shape will generally not reveal mechanical characteristics representative for such durability problems when subjected to uniform stress fields, a more realistic set up was developed. Attention particularly focused on the effect of bar corrosion on damage evolution in the concrete cover layer. Monolithic as well as a two-layered covercrete systems were emphasized experimentally and by a non-linear finite element method. It is shown that a relatively thin cover layer with slightly upgraded properties as to the rest of the covercrete will significantly enhance toughness of the composite. Since major cracking was found to start from the outside, a strain-hardening fibre reinforced cover sheet could additionally prolong serviceability life of the RC construction.
