Multiphysics Simulation of Recent Experiments on Alkali-Silica Reaction Expansion in Reinforced Concrete Members

Abstract

Alkali-silica reaction (ASR) is an important long-term degradation process in concrete structures. ASR produces expansive silica gel, causing local damage and macroscopic expansion, which can lead to cracking and damage throughout a structure due to load redistribution. ASR progression is affected by aggregate reactivity, alkali content in the hardened cement paste, temperature, moisture content, and stress. Numerical simulation is essential to predict the progression and effects of ASR on the performance of structures. Because of the interactions between thermal and moisture transport and mechanical deformation, it is important for numerical models to represent all these physical phenomena and the interactions between them. Simulations of ASR in reinforced concrete (RC) structures are further complicated by the need to capture interactions between concrete and embedded reinforcing bars. This paper describes the implementation of a scalable, coupled-physics ASR model for simulating RC structures and assesses the ability of that model to predict ASR-induced expansion in recent laboratory tests on RC block and beam specimens. These laboratory tests and the simulation approach were selected because of their applicability to RC structural-scale simulations. This validation study helps builds confidence the ablility of this approach to model ASR expansion in large, complex RC structures, which is a current high-priority need.