Effect of Exposure Conditions on the Long-Term Dielectric Properties of Mortar Samples Containing ASR Gel

dc.contributor.author Hashemi, Ashkan
dc.contributor.author Donnell, Kristen
dc.contributor.author Zoughi, Reza
dc.contributor.author Rashidi, Mehdi
dc.contributor.author Kurtis, Kimberly
dc.date 2018-02-17T22:57:15.000
dc.date.accessioned 2020-06-30T06:52:43Z
dc.date.available 2020-06-30T06:52:43Z
dc.date.issued 2016-01-01
dc.description.abstract <p>Alkali-silica reaction (ASR) may lead due damage in concrete structures due to chemical reaction between alkalis present in portland cement and amorphous or otherwise disordered siliceous minerals in particular aggregates [1]. Through this reaction, reactive silica binds with hydroxyl and alkali ions and forms a gel, known as ASR gel. Recently, microwave materials characterization techniques have shown great potential for detecting ASR in mortar. However, the comprehensive understanding of variables that affect the extent of ASR in mortar and their interaction with microwave signals, in particular the effect of exposure conditions, requires more investigations. Therefore, parameters related to exposure conditions must be considered when using microwave techniques for ASR detection and evaluation. In this paper, the effect of exposure conditions on ASR gel formation and microwave dielectric properties of mortar samples is investigated. To this end, extended measurements of the complex dielectric constants of three different sets of mortar samples are presented at S-band (2.6 – 3.95 GHz). The samples were cast with ASR-reactive aggregates, and exposed to different conditions. The results shows slightly different permitivities for the differently exposed samples, potentially indicating different amount of ASR gel. This observation was corroborated through UV fluorescence microscopy, where different amounts of ASR gel were observed in the samples. Moreover, the results indicate that ASR gel evolution may be better tracked through loss factor measurements, while pre-existing-gel may be better detected through permitivity measurements.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/qnde/2016/abstracts/129/
dc.identifier.articleid 5024
dc.identifier.contextkey 9262636
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath qnde/2016/abstracts/129
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/61871
dc.language.iso en
dc.relation.ispartofseries Review of Progress in Quantitative Nondestructive Evaluation
dc.source.bitstream archive/lib.dr.iastate.edu/qnde/2016/abstracts/129/234_Effect_of_Exposure.pdf|||Fri Jan 14 19:32:47 UTC 2022
dc.subject.disciplines Catalysis and Reaction Engineering
dc.subject.disciplines Electromagnetics and Photonics
dc.subject.disciplines Structural Materials
dc.title Effect of Exposure Conditions on the Long-Term Dielectric Properties of Mortar Samples Containing ASR Gel
dc.type event
dc.type.genre event
dspace.entity.type Publication
relation.isSeriesOfPublication 289a28b5-887e-4ddb-8c51-a88d07ebc3f3
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