Modelling the Multi-directional Distribution of ASR-Induced RC Expansions

Abstract

Deterioration attributed to alkali-silica reaction (ASR) is plaguing concrete infrastructure throughout the world. While ASR development in new concrete construction is easily mitigated through the use of nonreactive aggregates, low-alkali cements, and/or supplementary cementitious materials, engineers are challenged to identify and manage ASR effects in existing structures. At present, the implications of ASR on the structural performance of existing structures remains an area of great uncertainty. With an increasing inventory of ageing concrete infrastructure, there is a growing need for practical tools that can be used to reliably assess the performance of ASR-affected structures. This paper presents a simple modelling procedure used to estimate the multiaxial distribution of ASR-induced expansions in reinforced concrete (RC) elements. The model is principally based on classical concepts of RC element strain compatibility, force equilibrium, and RC-relevant constitutive relations; however, the model has also been developed in light of experimental results obtained from a recently performed ASR-affected RC cube element monitoring study conducted by the same authors. An overview of the development and resulting formulation of the proposed modelling procedure is presented, and the model is verified against experimental data currently available in the literature. Using only basic, easily defined input parameters (e.g., the concrete modulus of elasticity), expansion distribution patterns for the RC cube elements, and ASR-affected elements monitored by other researchers, are generated and shown to provide high-accuracy estimates of experimental measurements with limited computational effort.