Failure Mechanisms and Rehabilitation Scenarios for Concrete Hydroelectric Facilities Affected by Alkali–Aggregate Reaction

This work focuses on the failure mechanisms of concrete hydroelectric facilities affected by alkali–aggregate reaction (AAR). Identification of potential failure mechanisms is based on an original “top-down approach” using an AAR pushover analysis with multi-physics numerical simulation of a representative hydroelectric facility. Different global rehabilitation scenarios based on slot-cutting and grouting techniques are discussed and compared, using different performance metrics. A new quantitative performance metric, specifically developed for the nonlinear sophisticated analysis tool and considering the volumetric cracking caused by AAR is also suggested. Based on comparison results, a combination of grouting after a partial slot-cutting in the neighborhood of the discontinuities, appears to provide the best compromise in terms of stress relief and extent of cracking. New AAR benchmark problems, issued from the top-down approach, are also suggested for the first time in the literature.