Modelling the Mechanical Behavior of a Concrete Pavement Damaged by ASR

Expansions due to alkali-silica reaction (ASR) cause damage in civil engineering structures such as dams, bridges, pavements. A lot of work has been done to have a better understanding of the ASR mechanisms, both in the laboratory and in the field. The aim of this paper is to perform the forensic analysis of a concrete pavement located in Bécancour area (Québec) to understand its failure. This mechanical analysis is based on recent knowledges in terms of material and structural modelling of ASR. The data necessary to evaluate the mechanical behavior of structures damaged by ASR are first described (temperature, humidity, concrete delayed deformation, expansion potential). Modelling parameters are calibrated on expansion measured in the laboratory and used to predict expansion in outdoor conditions. The structural analysis of the pavement shows the importance of the combination of ASR expansion with cyclic thermal loading. Once the pavement joints are filled, due to ASR swelling, concrete dilatation induces important compressive stresses in summer. Such stress can lead to concrete damage and increases the risk of pavement buckling. This work emphasizes the importance of taking account of the combination between the different loadings (mechanical and environmental) and expansion in the mechanical analysis of structures damaged by ASR. It gives interesting teachings concerning concrete pavements but also other thin structures affected by such expansive mechanisms.