Accelerated Concrete-Cylinder Test for Alkali-Silica Reaction

The concrete-prism test (CPT, e.g., ASTM C1293-08b [ASTM C1293-08b: Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2013]) has been considered as the best index for alkali-silica reaction (ASR) field performance, but alkali leaching and test duration are still of concern. Reduction of test duration by increasing testing temperature (e.g., 60 degrees C) was proposed by several researchers to develop an accelerated version of the concrete-prism test (ACPT). However, it has been found that there is a significant reduction in expansion associated with more alkali leaching in the ACPT compared to the concrete-prism test (CPT). An accelerated concrete-cylinder test (ACCT) has been proposed in this study with no involvement of errors because of operation and temperature change along with arresting alkali leaching. The linear expansion of the ACCT measured at a temperature of 60 degrees C over a period of 1 month have been correlated with the 1-yr ASTM C1293 test to evaluate the ASR reactivity of aggregates. Cylinders made with highly reactive borosilicate glass balls were tested first to validate the proposed approach before any concrete-cylinder testing. The results indicate that (1) an expansion limit of 0.04 % using 0.82 % Na2O equivalent (Na2Oe) cement without alkali boosting after a testing period of 28 days is proposed for the ACCT to diagnose ASR aggregate reactivity, and (2) the proposed method can serve as an alternative to validate the ASR-resistant mix design (e.g., fly-ash contents).