AASHTO T 380-19 PDF Download

AASHTO T 380-19 is a standard method of test that allows for the detection of potential alkali reactivity of aggregates and the effectiveness of alkali-silica reaction (ASR) mitigation measures. The test is performed on miniature concrete prisms over a period of 56 days, although low/slow reacting aggregates may require an additional 28 days for assessment.

This standard is important for identifying aggregates that may undergo ASR, which is a chemical reaction between the alkalis present in cement and reactive silica in aggregates. ASR can lead to the formation of expansive gel, causing cracking and deterioration of concrete over time.

The test method also evaluates the effectiveness of supplementary cementitious materials (SCMs), such as fly ash, slag, and silica fume, in mitigating ASR. These materials are added to concrete to reduce the amount of alkalis available for reaction and minimize the risk of ASR.