In this paper, a nonlinear continuum theory is applied to model the thermomechanical behavior of concrete subjected to alkali-silica reaction. The reaction results in formation of silica gel around the aggregate particles, which expands triggering a progressive damage of the material. The expansion rate is assumed to be controlled by the alkali content, the magnitude of confining stress as well as the evolution of the temperature. The progress in the reaction is assumed to be coupled with degradation of the mechanical properties of concrete. First, the constitutive model describing the thermomechanical effects of the reaction, as recently developed by the second writer, is presented. Subsequently, numerical examples are provided to assess the performance of the proposed formulation. In particular, the model is applied to analyze different structural elements of the Beauharnois power plant, situated in Quebec, Canada.