Paulo Afonso Dam - Diagnosis and Prognosis of an AAR-Affected Dam

Alkali aggregate reaction (AAR) is one of the most harmful damage mechanisms affecting concrete infrastructure worldwide. Several numerical models have been developed in the past to appraise the expansion attained to date due to AAR and to predict its potential to generate further damage on affected infrastructure. Gorga et al. (2018) proposed a new finite element approach to assess AAR-affected structures accounting for both the most important microscopic and macroscopic aspects affecting the chemical reaction. The most distinct characteristic of this methodology is that it does not oversimplify nor overcomplicate the analysis of the reaction, while still being capable of accurately representing the anisotropic expansion and its macroscopic consequences. Slender structures have already been successfully simulated using this approach. However, it has been found that AAR-affected slender and massive structures do not necessarily behave equally, which is mostly due to the lack (or very little amount) of leaching and the potential alkali release from aggregates at later stages of the reaction on massive structures. This paper presents the validation analyses and simulations performed on an ASR-affected dam in Brazil (Paulo Afonso IV) in order to appraise the accuracy of the prior proposed approach for massive structures.