Finite element analysis of concrete swelling due to alkali-aggregate reactions in dams

Abstract

Many concrete dams throughout the world are suffering from deteriorations induced by alkali-aggregate reaction (AAR) that impair the durability, serviceability, and might also affect, in the long term, the safety of the installation. AAR produces concrete expansion, and generally leads to a loss of strength, stiffness (cracking), and generates undesirable deformations and disturbances in the equilibrium of internal forces. This paper first presents a brief review of the physical processes that control the structural behaviour of concrete dams suffering from AAR. A methodology to distribute the observed concrete expansion in proportion to the compressive stress state, temperature, moisture, and reactivity of the constituents is then proposed for the numerical modelling of AAR concrete swelling in dams. A case study on a concrete spillway pier that is affected by AAR is presented to illustrate some features of the proposed methodology.