FINITE-ELEMENT ANALYSIS OF CONCRETE SWELLING DUE TO ALKALI-AGGREGATE REACTIONS IN DAMS

Many concrete dams throughout the world are suffering from deteriorati ons induced by alkali-aggregate reaction (AAR) that impair the durabil ity, serviceability, and might also affect, in the long term, the safe ty of the installation. AAR produces concrete expansion, and generally leads to a loss of strength, stiffness (cracking), and generates unde sirable deformations and disturbances in the equilibrium of internal f orces. This paper first presents a brief review of the physical proces ses that control the structural behaviour of concrete dams suffering f rom AAR. A methodology to distribute the observed concrete expansion i n proportion to the compressive stress state, temperature, moisture, a nd reactivity of the constituents is then proposed for the numerical m odelling 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. Copyright (C) 1996 Elsevier Scie nce Ltd.