Advances in Test Methods to Evaluate Alkali-Aggregate Reactivity in Job Concrete Mixtures-Emerging Rapid Aggregate and Concrete Test Methods for Evaluating ASR-Resistant Job Concrete Mixes (Recorded presentation)

Emerging Rapid Aggregate and Concrete Test Methods for Evaluating ASR-Resistant Job Concrete Mixes (Recorded presentation)

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Video Summary

The presentation addresses the limitations of current tests for assessing aggregate reactivity and alkali-silica reaction (ASR) potential in concrete. Traditional tests like the 1260 accelerated mortar bar and 1293 concrete prism tests are unreliable due to varying alkali content and severe test conditions, often resulting in false positives and negatives. The speaker proposes a more effective method combining rapid chemical testing of aggregates and concrete pore solution analyses to determine aggregate reactivity, activation energy, and threshold alkalinity. This approach allows for tailored mix designs considering regional conditions and specific material characteristics. By integrating these improved testing protocols, the goal is to design more robust ASR-resistant mixes with an emphasis on rapid assessment and validation of aggregate reactivity and proper fly ash use, especially accounting for differences in environmental exposures across regions like Texas. The ultimate aim is to establish a more reliable national standard for concrete testing and mix design.

Keywords

alkali-silica reaction

aggregate reactivity

concrete testing

mix design

ASR-resistant