Скачать или смотреть Laboratory vs Field Performance of AAR-Affected Concrete: Risks Associated with Accelerated Test

Laboratory vs Field Performance of AAR-Affected Concrete: Risks Associated with Accelerated Test Procedures
Presented By: Ana Bergmann
Affiliation: University of Ottawa
Alkali-aggregate reaction (AAR) poses significant durability challenges for concrete infrastructure worldwide. Prevention remains the most effective approach, as addressing AAR after the reaction is triggered is challenging. While accelerated laboratory tests like the Accelerated Mortar Bar Test (AMBT) and Concrete Prism Test (CPT) are frequently employed to evaluate aggregate reactivity, discrepancies between laboratory outcomes and field performance persist. These disparities have not yet been fully quantified, so further analysis is requested. Therefore, this study applies multifactorial statistical and probabilistic methods to bridge this gap, combining laboratory and field data. Utilizing Bayesian analysis and Beta distribution modeling, the research evaluates the probability of AAR development under various conditions. Key parameters include laboratory test results, environmental factors, and alkali loading. The findings show that AMBT outperforms in identifying non-reactive cases for both mixes with and without SCMs, while both AMBT and CPT demonstrate similar reliability for detecting reactive cases, with CPT slightly better at higher alkali levels. Additionally, the reliability of these methods varies with environmental conditions: warmer climates and high alkali without SCMs increase misclassification risk, while cooler climates with low alkali levels and SCM presence enhance test reliability. This nuanced understanding supports improved AAR risk assessments, facilitating the development of strategies for better predicting field occurrences.