Alkali-silica reaction expansion model for confined concrete with stress-dependency and casting direction anisotropy

Alkali-silica reaction (ASR) is a deleterious chemical reaction between alkali hydroxyl ions and types of silica found in some aggregates of concrete. Owners and regulators of nuclear power plants aim to ensure the safety of the concrete structures with optimal maintenance strategies. A new model was developed for predicting the expansion of concrete structures affected by alkali-silica reaction. The model includes a novel combination of existing models as an alkali-silica reaction advancement model, a casting direction anisotropic expansion model, a stress-dependent anisotropic expansion model, and a material property evolution model dependent on the degree of ASR expansion. The model parameters were calibrated based on existing literature data and data generated by previous efforts of this study. The calibrated model was then validated with the experiments carried out in previous efforts of this study. The model was shown to accurately predict the ASR-expansion of large-scale reinforced concrete specimens with confinement.

Automated summary

Alkali-silica reaction (ASR) is a harmful chemical reaction between alkali hydroxyl ions and silica in concrete. A new model has been developed to predict the expansion of concrete structures affected by ASR. The model combines existing models for ASR advancement, casting direction anisotropic expansion, stress-dependent anisotropic expansion, and material property evolution dependent on the degree of ASR expansion. The calibrated model accurately predicts the ASR expansion of large-scale reinforced concrete specimens.