Prediction of Residual Expansion Based on ASR Acceleration Test Results of Cores Sampled at Early Age

When alkali-silica reaction (ASR) occurs in concrete structures, the residual expansion is evaluated by conducting accelerated expansion tests on sampled cores. However, there is still an issue in terms of quantitative prediction of ASR potential: when and to how much the expansion will occur. In this study, test methods to properly detect residual expansion and future prediction methods were investigated. Several cores were sampled in the early age of concrete blocks under conditions causing ASR, and expansion tests were conducted on these cores under several accelerated conditions. The observed expansion behaviors were regressed numerically on the curves. The core expansion curves were then converted to the case at outdoor temperatures using temperature correction factors obtained by concrete prism test (CPT) at different accelerated temperatures with similar concretes. The predicted results were validated by comparison with the expansion data of concrete blocks of the same mix exposed in field conditions for 6 years. Furthermore, the results were compared with previous cases of residual expansion experiments using cores taken during the accelerated stage of expansion.