Evaluation of a Standardized ASR Testing Procedure for Aggregates in View of Additional Testing Using Simulated Pore Solutions Following Outdoor Exposure Sample Data from Highways of Over 10 years of Service Life

Established testing procedures for ASR risk of aggregates do not always reflect the actual reactions taking place in real life exposure sites. In this study the behavior and performance of three different aggregates used in Austrian highways was compared in standardized testing procedures (ÖNORM B 3100, 38 ℃) and non-standardized tests supported by data from 10 year old highways built with the aggregates. The testing showed that the aggregates were usually a lot less reactive in real life exposure settings than in standardized settings. The modification of parameters within the testing procedures (e.g. cement type, air void content, water binder ratio) lead to the following insights: The used cement type is much more significant for the expansion properties than amount of cement used, air void content and water binder ratio. The alternative testing procedure with a storage solution modelled after natural measured alkali amounts in the road samples showed an over 50% reduced expansion compared to the standard solution at the same testing temperature. An adaption of the standardized testing procedure was advised, distinguishing between upper layer and lower layers of concrete pavements. This would allow a first step for the wider use of aggregates that are considered reactive under current standardized testing but proved sufficient in additional testing procedures and real-life exposure settings.