The Laboratory of Construction Materials in Lausanne has been studying the alkali-silica reaction for more than 10 years, advancing the understanding of the reaction, and also producing microstructural models which can be used to predict quantitatively the degradation of affected concrete. This paper provides an overview of these developments. The authors present experimental evidence of the link between aggregate degradation and expansion, a formulation of the microstructural model and a proposition for a macrostructural model derived from their computations.