A review of long-term expansion prediction model of concrete suffering alkali-aggregate reaction

Alkali-aggregate reaction is called the “cancer” of concrete and is one of the important factors affecting the durability of concrete. For the concrete structure with active aggregate, how to predict the long-term deformation of concrete caused by alkali-aggregate reaction and reasonably evaluate the overall safety of the structure is a problem of vital concern to the project. In this paper, the research progress of long term deformation prediction models for alkali-aggregate reaction of concrete is reviewed. The existing models are classified into 5 categories: mathematical modeling of macroscopic expansion, phenomenological model of macroscopical deformation of structures, models based on aggregate expansion, models based on ASR gel and models based on material migration. The advantages, disadvantages and application scope of various models are analyzed. It is proposed that the prediction model of ASR long-term expansion needs to consider the effect of alkali ion diffusion into the aggregate, SiO₂ dissolution and the composition of ASR gel, and the reaction ring model or gel pocket model should be selected according to the petrographic analysis.