Pennsylvania’s Experiences and Challenges Implementing Comprehensive ASR Specifications 1990–2023

In 2015 the Pennsylvania Department of Transportation (PennDOT) and the Pennsylvania Aggregates and Concrete Association (PACA) implemented a unique concrete aggregate testing and evaluation protocol to mitigate the risk of deleterious alkali-silica reaction (ASR). The novel/cutting-edge approach, at that time, utilized widespread ASTM C1293 Concrete Prism tests to evaluate aggregate reactivity. The reactivity testing was required to be repeated once every five years. Based on the aggregate reactivity levels, prescriptive amounts of supplementary cementitious materials (SCMs) are utilized to mitigate the reaction, where increased reactivity levels require increased amounts of SCMs. The implementation of this specification brought about beneficial results, along with some known and a few unanticipated challenges. With the implementation of the new specifications and the increase in SCMs, the northeast portion of the state saw a dramatic increase in scaling of flatwork. This presentation will review the reasons for adopting these specifications, the benefits realized, challenges faced during implementation, and current challenges.