• Title/Summary/Keyword: 알칼리-골재 반응

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Characteristics of Alkali-Silica Reaction according to Types and Substitution Ratios of Mineral Admixtures in Korea (국내 광물성 혼화재의 종류 및 혼입률에 따른 알칼리-실리카 반응 특성)

  • Kim, Seong-Kwon;Hong, Seung-Ho;Hur, In;Yun, Kyong-Ku
    • Journal of the Korea Concrete Institute
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    • v.23 no.1
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    • pp.49-55
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    • 2011
  • The distresses of alkali-silica reaction (ASR) was recently reported at highway cement concrete pavement in Korea, which showed typical cracking and spalling patterns of ARS. Korea is was no longer safe zone against ASR, needding to find a control methodology against ASR. The purpose of this research was to provide a control methodology against ASR using mineral admixtures through a series of laboratory test program. Laboratory works included the accelerated mortar bar test (AMBT) by ASTM C 1260 regulation with five types of aggregate and three types of mineral admixtures (fly ash, ground granulated blast-furnace slag and silica fume). The result of ASTM C 1260 test for five types of aggregates without mineral admixtures showed that Siltstone and Mudstone were found to be "reactive." Tuff and Andesite-1 were found to be "possiblely reactive." In case of concrete mixed with 10, 20, and 30% fly ash, all specimens except Mudstone mixed with 10% FA were found to be "non-reactive". In cases of concrete mixed with 30, 40, and 50% ground granulated blast-furnace slag and 5, 7.5, and 10% silica fume, all specimens were found to be "non-reactive." These results could be selectively applied in constructions in Korea.

Evaluation of Mechanical Properties and Alkali-Silica Reaction of High Strength Mortar Using Waste Glass Sand (폐유리 잔골재를 치환한 고강도 모르타르의 역학적 특성 및 알칼리-실리카 반응 평가)

  • Eu, Ha-Min;Kim, Gyu-Yong;Choe, Gyeong-Cheol;Son, Min-Jae;Nam, Jeong-Soo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.4
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    • pp.528-536
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    • 2020
  • In this study, high strength mortar and normal strength mortar using waste glass sand were evaluated. The main parameters studied were mechanical properties, alkali-silica reaction(ASR) and residual mechanical properties after ASR. As a result of this experiment, it was found that the increase in strength of the mortar has a limitation in improving the slip of the waste glass sand(GS), and rather, it causes a larger ASR. However, the possibility of improving the slip of GS was confirmed by the temporary increase of initial residal compressive and flexural strength of the mortar containing GS after the ASR. Therefore, to improve the slip of GS, the additional research is required, such as modification of the surface of GS and the incorporation of a binder which can increase the strength and makes matrix compact.

Strength Development of the Concrete Incorporating Blast Furnace Slag and Recycled Aggregate as Alkali Activator (고로슬래그 미분말과 알칼리 자극재로서 순환골재를 사용하는 콘크리트의 강도발현 특성)

  • Kim, Jun-Ho;Han, Min-Cheol;Han, Cheon-Goo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.2 no.2
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    • pp.107-114
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    • 2014
  • The objective of this study is to evaluate the strength development of blast furnace slag concrete in response to the use of recycled aggregate as alkali activator. The influence of the amount of recycled aggregate was evaluated depending on different ratios of replacement for each RFA and RCA to NFA and NCA, respectively. The results indicated that as replacement of RFA and RCA increased, their strength exhibited to be increased. This was due to the fact that the latent hydraulic properties of blast furnace slag was activated by the alkali in recycled aggregates. However, in case of 365-days, it showed lower compressive strength than using NA(natural aggregates) which could be explained as the exhaustively use of alkali containing in RA. The specimens using RA showed about 90% of compressive strength comparing with specimens using NA.

An Experimental Study on the Alkali-Silica Reaction of Crushed Stones (Part 3 : The Influence of the Innocuous Aggregate Content and Pozzolanic Materials to the Alkali-Silica Reaction) (쇄석골재의 알칼리-실리카 반응에 관한 실험적 연구 (제3보 : 무해골재 치환량 및 포졸란물질이 알칼리-실리카 반응에 미치는 영향))

  • 이양수;정재동;노재호;조일호;윤재환;이영수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.04a
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    • pp.169-173
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    • 1994
  • Recently, the use of crushed stones is increased due to the shortage of natural aggregates. In the previous papers of part 1 and 2, we got the conclusions that some of crushed stones have the characteristic of alkali-silica reaction(ASR). And these reactions are influenced by the amount and type of alkali in cement. The purpose of this paper is how to prepare for the prevention against alkali-silica reaction. As a solution of problems, we have conducted the experiments of two methods. One was the replacement of innocuous aggregates instead of reactive aggregates, the other was the addition of various pozzolanic materials. As a result, we found that the expansion by alkali-silica reaction in mortar bar could be effectively decredsed by upper methods.

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Effect of Surface Modification of Waste Glass for Fine Aggregate on the Mechanical Properties and Alkali Silica Reaction of Mortar (잔골재용 폐유리의 표면개질이 모르타르의 역학적 특성 및 알칼리 실리카 반응에 미치는 영향)

  • Son, Min-Jae;Kim, Gyu-Yong;Lee, Sang-Kyu;Sasui, Sasui;Eu, Ha-Min;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.23-24
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    • 2020
  • In this study, effect of surface modification of waste glass for fine aggregates on the mechanical properties and alkali silica reaction of mortar was analyzed. As a result, it was confirmed that the incorporation of waste glass fine aggregate decreases the mechanical properties of the mortar and increase the alkali silica reaction expansion. On the other hand, the surface modification of the waste glass fine aggregate is effective in improving this problem. However, unlike green and brown waste glass, it is judged that an additional experiment to determine the cause is necessary for white waste glass where alkali silica reactive expansion occurs extremely.

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Effect of Waste Glass Fine Aggregate on Mechanical Properites and Alkali-Silica Reaction(ASR), After ASR Residual Mechanical Properties of High Strength Mortar (폐유리 잔골재가 고강도 모르타르의 역학적 특성 및 알칼리-실리카 반응(ASR), ASR 후, 잔류 역학적 특성에 미치는 영향)

  • Eu, Ha-Min;Kim, Gyu-Yong;Son, Min-Jae;Sasui, Sasui;Lee, Yae-Chan;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.31-32
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    • 2020
  • This study measured the mechanical performance and residual strength of high strength/normal strength mortar mixed with waste glass fine aggregate after alkali-silica reaction and alkali-silica reaction. As a result, the effect of improving the slip phenomenon of the waste glass fine aggregate in the high-strength mortar was not significant, but rather the amount of ASR was increased.

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Effect of the replacement rates of Waste Glass Fine Aggregate on the Mechanical Properties and Alkali - Silica Reaction of Mortars with different W/C Ratio - (폐유리 잔골재 대체율이 물시멘트비가 다른 모르타르의 역학적 특성 및 알칼리 -실리카 반응에 미치는 영향 -)

  • Eu, Ha-Min;Kim, Gyu-Yong;Nam, Jeong-Soo;Son, Min-Jae;Sasui, Sasui;Lee, Yae-Chan
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.195-196
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    • 2020
  • This study evaluated the mechanical properties and alkali silica reaction of mortar according to the mixing ratio of waste glass. As a result, as the mixing ratio of the waste glass increased, the compressive and flexible strength of the mortar decreased due to the slip of aggregate, and the alkali-silica reaction(ASR) increased. So, it is considered that research is needed to prevent slip and ASR of the waste glass aggregate in order to use the waste glass as a fine aggregate for concrete.

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