DEVELOPMENT OF STRESSES IN CONCRETE STRUCTURES WITH ALKALI-SILICA REACTIONS

The present paper deals with the development in time of stresses and strains in concrete structures suffering from alkali-silica reaction (ASR). The properties of the concrete are combined with the.dimensions of the structure in which the concrete is placed. A geometrical model that permits the determination of stresses and strains is established for concrete. This model is combined with a computer program which is able to calculate the moisture flow into a given structure, and this moisture flow is connected with the development of ASR. The resulting calculation takes into account the dimensions of the structure, the concrete quality, the content of reactive silica and the climate around the structure, as it predicts the strains and stresses developed in concrete structures suffering from ASR. It is shown that cracks are developed locally around the reacting particles, and it is proposed that most of the cracks that become visible on the surface of a structure originate from the period of construction.