Development of a Screening Tool for Rapid Fly Ash Evaluation for Mitigating Alkali Silica Reaction in Concrete
Performance-based approaches to evaluate fly ash effectiveness in suppressing alkali silica reaction (ASR) require testing for a range of replacement levels to determine optimum fly ash dosage. Current approaches of ASR evaluation, that is, determining optimum fly ash dosage for ASR mitigation, are impractical as a mix design tool for new concrete construction. Therefore, in the present work a screening tool is developed to predict optimum fly ash dosage to suppress ASR in concrete mixes. The screening tool uses water-soluble (readily available) alkali from fly ash and cement to determine pore solution alkalinity (PSA) of concrete mixes for different fly ash replacement levels. The optimum fly ash dosage in concrete to mitigate ASR is estimated based on the PSA and aggregate threshold alkalinity (THA) relationship, that is, PSA should be =THA to make the mix ASR mitigated. Results from the screening tool demonstrate an 82% reliability in predicting fly ash dosage necessary to keep expansions below 0.04% based on AASHTO TP 142 tests for ASR expansion. In addition, a multiple non-linear regression model was developed to predict water-soluble alkali from fly ashes in place of testing using 50 experimental data points from laboratory measurements and literature studies. Overall, the screening tool presents a rapid and reliable approach to determine the optimum fly ash content required for ASR mitigation based on pore solution composition of mixes and aggregate reactivity.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/03611981
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Supplemental Notes:
- Pravin Saraswatula https://orcid.org/0000-0001-7426-4429 © National Academy of Sciences: Transportation Research Board 2022.
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Authors:
- Saraswatula, Pravin
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0000-0001-7426-4429
- Mukhopadhyay, Anol
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0000-0002-2428-5077
- Liu, Kai-Wei
- Publication Date: 2022-11
Language
- English
Media Info
- Media Type: Web
- Features: References;
- Pagination: pp 583-595
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Serial:
- Transportation Research Record: Journal of the Transportation Research Board
- Volume: 2676
- Issue Number: 11
- Publisher: Sage Publications, Incorporated
- ISSN: 0361-1981
- EISSN: 2169-4052
- Serial URL: http://journals.sagepub.com/home/trr
Subject/Index Terms
- TRT Terms: Admixtures; Alkali; Alkali silica reactions; Fly ash; Mix design
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 01847946
- Record Type: Publication
- Files: TRIS, TRB, ATRI
- Created Date: Jun 3 2022 9:00AM