The Kingston Exposure Site for ASR at 32 Years

Abstract

This paper reports on the performance of the Ontario Ministry of Transportation (MTO) Kingston Exposure Site (KES) experiment for ASR after 32 years. KES was constructed in 1991 for two main purposes: 1) to test the effectiveness of measures to control or mitigate ASR and 2) to compare results of short-term lab testing with long term field performance. The KES consists of concrete produced from six different concrete mixtures using various cements and supplementary cementing materials (SCMs) in combination with the Spratt Aggregate. The mixtures were cast into 13 beams 0.6 × 0.6 × 2 m (6 reinforced and 7 non-reinforced beams), and 6 sidewalk slabs 0.2 × 1.2 × 4 m. At 32 years, all but two mixtures are demonstrating unacceptable field expansions in the unreinforced beams. Comparison of the field expansions with laboratory test data for the same mixtures reveals that the concrete prism expansion test (CPT) tends to underpredict actual field expansion, and that the accelerated mortar bar test (AMBT) is likely a better predictor of the potential efficacy of selected mitigative measures for countering ASR. The raw data from KES has been released and is publicly available to the AAR research community for download through MTO’s Technical Publications website.