Chemo-hygro-mechanical modelling and numerical simulation of concrete deterioration caused by alkali-silica reaction

The paper presents a macroscopic model for the description of concrete deterioration caused by alkali-silica reaction (ASR). Based on concepts of the Theory of Porous Media, concrete is regarded as a mixture of three superimposed and interacting constituents: the skeleton, the pore liquid and the pore gas. The skeleton in turn represents a mixture of the unreacted, unswollen and the already reacted, swollen material. When ASR takes place, mass of the unreacted material is non-instantaneously converted into mass of the reacted material. Since the unreacted material is characterized by a smaller density, the material swells. In the proposed model the dependence of the kinetics and the magnitude of the swelling process on the moisture content is taken into account. The properties of the model are investigated by means of one-dimensional parametric studies on the material level. Finally, the suitability of the model on the structural level is demonstrated by means of the numerical simulation of a concrete beam. It turns out, that deterioration by ASR is driven by the simultaneous activation of moisture diffusion and reaction kinetics resulting in a drastic reduction of the limit load and stiffness of concrete structures. Copyright (C) 2004 John Wiley Sons, Ltd.