ASTM C1778-22 PDF Download

ASTM C1778-22 is a standard guide that provides guidance on reducing the risk of deleterious alkali-aggregate reaction (AAR) in concrete construction. The standard focuses on both potentially alkali-silica reactive (ASR) and alkali-carbonate reactive (ACR) aggregates, which can cause expansion and damage to concrete structures over time.

The guide outlines standardized testing procedures that can be used to identify ASR and ACR aggregates, allowing engineers and contractors to assess the potential risk of AAR in their concrete mixtures. Based on the test results, mitigation options are provided to minimize the risk of expansion when using ASR aggregates. These mitigations can be selected using prescriptive or performance-based alternatives, depending on the specific project requirements.

Preventive measures for ACR aggregates, on the other hand, are limited to avoidance of use. This means that if an aggregate is found to be alkali-carbonate reactive, it should not be used in concrete construction to reduce the risk of deleterious reactions.

The guide also emphasizes that the potential for deleterious reactions is influenced not only by the concrete mixture but also by the in-service exposure. Therefore, the standard provides guidance on the types of structures and exposure environments where AAR may be of concern, enabling designers and engineers to make informed decisions regarding the suitability of specific aggregates and mitigation measures for their intended applications.