Long Term Efficacy of Fly Ash in Mitigating Alkali-Silica Reaction Assessed by Pore Solution Method

This study investigates the effect of pore solution on alkali-silica reaction (ASR) expansion and mitigation using the simulated pore solution method. The simulated pore solution method is an accelerated ASR test developed at EPFL, Switzerland which uses the pore solution alkali concentration of the binder of interest at 28 days as basis of the storage solution. This study presents the 4-year expansion results of concrete prisms with reactive Australian aggregate (dacite), with and without 25% fly ash stored at 38 ℃. Results show no expansion in concrete prisms with 25% fly ash even if the cement alkali content was boosted up to 1%Na2Oeq. Extensive cracking was notable in the concrete without fly ash while the concretes with fly ash show only minimal presence of fine cracks.