The effect of delayed ettringite formation and alkali-silica reaction in concrete

碩士 === 國立中央大學 === 土木工程研究所 === 100 === This paper presents the determination of concrete deterioration, which is contributed by delayed ettringite formation (DEF) and alkali-silica reaction (ASR). The deterioration process of either DEF or ASR is associated with expansion. This paper employed “self-d...

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Main Authors: Wei-min Kuo, 郭偉民
Other Authors: Yong-Ming Tien
Format: Others
Language:zh-TW
Published: 2012
Online Access:http://ndltd.ncl.edu.tw/handle/67847647595220920433
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spelling ndltd-TW-100NCU050150922015-10-13T21:22:38Z http://ndltd.ncl.edu.tw/handle/67847647595220920433 The effect of delayed ettringite formation and alkali-silica reaction in concrete 延遲性鈣礬石形成與鹼-骨材反應引致劣化機制 Wei-min Kuo 郭偉民 碩士 國立中央大學 土木工程研究所 100 This paper presents the determination of concrete deterioration, which is contributed by delayed ettringite formation (DEF) and alkali-silica reaction (ASR). The deterioration process of either DEF or ASR is associated with expansion. This paper employed “self-designed expansionary test”, Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometer (EDS) to observe DEF, ASR, and coupled DEF-ASR reactions mechanisms. The mortar bars were used in the proposed expansionary test. One kind of mortar bar consisted of standard sand and cement; the other consisted of andesite and cement. Parametric study is also introduced in this paper, all of mortar bars were placed at different sulfur contents (0% and 5.2%) and various curing temperatures (20℃, 70℃, and 85℃) in experimental conditions. The results show that the curing temperature and sulfur content play important roles for DEF, which will induce great expansion by many micro-cracks surrounding aggregates at the latter period of mortar age. ASR is based upon the environments of alkali content, water content, and reactive aggregates in mortar bars. Moreover,micro-features and chemical compositions of delayed ettringite crystal and alkali-silica gel can be precisely observed by using SEM and EDS. Yong-Ming Tien 田永銘 2012 學位論文 ; thesis 92 zh-TW
collection NDLTD
language zh-TW
format Others
sources NDLTD
description 碩士 === 國立中央大學 === 土木工程研究所 === 100 === This paper presents the determination of concrete deterioration, which is contributed by delayed ettringite formation (DEF) and alkali-silica reaction (ASR). The deterioration process of either DEF or ASR is associated with expansion. This paper employed “self-designed expansionary test”, Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometer (EDS) to observe DEF, ASR, and coupled DEF-ASR reactions mechanisms. The mortar bars were used in the proposed expansionary test. One kind of mortar bar consisted of standard sand and cement; the other consisted of andesite and cement. Parametric study is also introduced in this paper, all of mortar bars were placed at different sulfur contents (0% and 5.2%) and various curing temperatures (20℃, 70℃, and 85℃) in experimental conditions. The results show that the curing temperature and sulfur content play important roles for DEF, which will induce great expansion by many micro-cracks surrounding aggregates at the latter period of mortar age. ASR is based upon the environments of alkali content, water content, and reactive aggregates in mortar bars. Moreover,micro-features and chemical compositions of delayed ettringite crystal and alkali-silica gel can be precisely observed by using SEM and EDS.
author2 Yong-Ming Tien
author_facet Yong-Ming Tien
Wei-min Kuo
郭偉民
author Wei-min Kuo
郭偉民
spellingShingle Wei-min Kuo
郭偉民
The effect of delayed ettringite formation and alkali-silica reaction in concrete
author_sort Wei-min Kuo
title The effect of delayed ettringite formation and alkali-silica reaction in concrete
title_short The effect of delayed ettringite formation and alkali-silica reaction in concrete
title_full The effect of delayed ettringite formation and alkali-silica reaction in concrete
title_fullStr The effect of delayed ettringite formation and alkali-silica reaction in concrete
title_full_unstemmed The effect of delayed ettringite formation and alkali-silica reaction in concrete
title_sort effect of delayed ettringite formation and alkali-silica reaction in concrete
publishDate 2012
url http://ndltd.ncl.edu.tw/handle/67847647595220920433
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