• Title/Summary/Keyword: heat of hydration reducing

Search Result 84, Processing Time 0.028 seconds

The Characteristics of Hydration Heat Generation of Low Heat Concrete using Hydration Heat Reducing Admixtures (분말형 수화열저감재를 사용한 저발열 콘크리트의 수화발열 특성)

  • Kim, Yong-Ro;Jung, Yang-Hee;Lee, Sang-Ho;Kim, Do-Su;Khil, Bae-Su;Kim, Won-Ki
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.11a
    • /
    • pp.709-712
    • /
    • 2006
  • It is necessary to develop a new technology for controling thermal cracking by hydration heat according to the increase construction of massive concrete structures, high strength concrete and early strength concrete. Therefore, it was investigated the characteristics of hydration heat generation of low heat concrete using hydration heat reducing admixtures in this study. To investigate the performance of hydration heat reducing admixtures, it was evaluated hydration heat according to the kind and replacement ratio of phase change material series I, II and the way of using hydration heat reducing admixtures in series III.

  • PDF

Hydration-heat Characteristics of Mortar mixed with Strontium Hydration-heat Reducing Material (스트론튬계 수화열저감재 혼입 모르타르의 수화발열 특성)

  • Kim, Goo-Hwan;Kim, Gyu-Yong;Lee, Sang-Kyu;Hwang, Eui-Chul;Kim, Gyeong-Tae;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2018.11a
    • /
    • pp.33-34
    • /
    • 2018
  • As a result of measuring the compressive strength and semi-adiabatic temperature rise of the mixed mortar, it was confirmed that the mortar mixed with the hydration heat reducing material is effective. On the other hand, the compressive strength showed similar strength to that of moderate heat Portland cement until the age 7 days, but after that, the tendency of the strength development to be delayed was confirmed.

  • PDF

Field Application of a Technique for Reducing Hydration Heat-induced Cracks in Mass Concrete (수화발열량차 공법을 이용한 매트기초 매스콘크리트 균열저감 및 현장적용)

  • Jo, Man-Ki;Kim, Jun-Ho;Heo, Young-Sun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2012.11a
    • /
    • pp.55-57
    • /
    • 2012
  • In this study, the field applicability on reducing the heat of hydration of mass concrete by using the hydration heat difference method is analyzed with the following summary. As a result of applying the hydration heat difference method by using low heating combination, the temperature difference between the central part and the surface part of mass material was reduced, and as a result of visual observation, there was no showing of cracks by the hydration heat on the upper surface part. Therefore, the cracking index of the field to apply this method was shown to be approximately 1.57 with very little crack occurrence probability of less than 3%.

  • PDF

Experimental Study on the Generation of Hydration Heat of Binder using Latent Heat Material (잠열재를 사용한 결합재의 수화발열 특성에 관한 실험적 연구)

  • Kim, Yong-Ro;Kim, Do-Su;Khil, Bae-Su;Kim, Ook-Jong;Lee, Do-Bum
    • Journal of the Korea Institute of Building Construction
    • /
    • v.9 no.3
    • /
    • pp.103-107
    • /
    • 2009
  • It is necessary to develop a new technology for effectively controlling thermal crack caused hydration heat according to the increasing construction of large size massive concrete structures such as mat foundation of high-rise building. Therefore, to develop a new technology for reducing hydration heat of large size massive concrete in this study, it was investigated hydration heat generation properties of binder using latent heat materials. As a test result, it was confirmed that latent heat materials were advanced on the reduction of hydration heat and control of thermal crack. It is expected to be applied as the excellent technology on the management of hydration heat and thermal crack in large size massive concrete structures.

Reducing effect for Hydration Heat of High-Strength Concrete according to Admixture Types and Replacement Ratios (혼화재 종류 및 대체율에 따른 고강도콘크리트의 수화열 저감 효과)

  • 유범재;김용로;최세진;김상윤;김상규;김무한
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2001.11a
    • /
    • pp.409-414
    • /
    • 2001
  • The hydration of cement paste occurs when the cement is mixed with water. During the hydration, hydration heat causes the thermal stress depending on the size of concrete and the cement content. Especially in the high-strength concrete, we must give care to the concrete due to its large cement content. In this study, conduction calorimeter and concrete insulation hydration heat meter were used to investigate the hydration heat characteristics of cement and concrete. To reduce hydration heat of high-strength concrete, several types of replacement of fly-ash and blast-furnace slag powder were used in this experiment.

  • PDF

A Fundamental Study on the Control of Hydration Heat of Mass Concrete Using Setting Time Difference (응결시간차를 활용한 매스콘크리트의 수화열 조정에 관한 기초적 연구)

  • 배정렬;윤치환;김기철;한민철;오선교;한천구
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2002.05a
    • /
    • pp.41-45
    • /
    • 2002
  • Placing lift is applied to place mass concrete in order to reduce thermal cracks by hydration heat. But they results in cold joint between placing lifts, which bring about the loss of strength, water tightness and undesirable appearance. Therefore, in this paper, mechanical and hydration heat of mass concrete using super retarding agent developed through previous study are investigated in order to reduce the hydration heat and place it without place lift. According to test results, placing lifts combined with normal concrete and concrete containing super retarding agent have positive effects on reducing hydration heat. Especially, the crack index by thermal stress of the concrete containing super retarding agent less than a quarter, compared to that of plain concrete without placing lifts, and less than a half, compared to that of plain concrete with placing lifts.

  • PDF

A Study on the Fundamental and Heat of Hydration Properties of Fly Ash Replacement Concrete Mixed with Coal Gasification Slag for Fine Aggregate (석탄 가스화 용융 슬래그를 잔골재로 사용하는 플라이애시 치환 콘크리트의 기초적 특성 및 수화열에 관한 연구)

  • Han, Min-Cheol;Choi, Il-Kyung
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.36 no.1
    • /
    • pp.155-162
    • /
    • 2020
  • The aim of the research is to investigate the fundamental properties and heat of hydration reducing performance of the fly ash incorporated concrete mixture when the coal gas slag (CGS) from integrated gasification combined cycle (IGCC) is used as fine aggregate. From the results of the experiment, the workability was generally increased and the air content was decreased up to one to four percent with increasing the replacing ratio of CGS to fine aggregate. The compressive strength was similar or increased within five percent to the Plain mixture when the CGS was used as a fine aggregate. When the CGS and fly ash were used same time, the heat of hydration reducing performance was improved than single using cases either CGS or fly ash. Based on the results, for the concrete mixture using CSG as a portion of the combined fine aggregate, the general properties were improved and heat of hydration was decreased approximately 16 % when the fly ash was replaced 30 % to cement and the CGS was replaced less than 50 % to fine aggregate.

Hydration Heat and Crack-Reducing Properties of Cement Mortar Added Fluosilicate Salt Based Hydration Heat Reducer (규불화염계 수화열 저감제가 첨가된 시멘트 모르타르의 수화열 변화 및 균열저감 특성)

  • Kim, Jin-Yong;Lee, Hyo-Song;Rhee, Young-Woo;Kim, Do-Su;Lee, Byoung-Ky;Khil, Bae-Su;Han, Seung-Gu
    • Journal of the Korean Ceramic Society
    • /
    • v.42 no.3 s.274
    • /
    • pp.198-204
    • /
    • 2005
  • Fluosilicate salts based hydration heat reducer(SWP-HR), used in this study, is composed of fluosilicate salts, soluble silica, aromatic polymer condensate and nitrate salt based inorganic compound with latent heat property. Effects of SWP-HR addition on the hydration heat and anti-crack property of cement mortar were investigated. Adiabatic hydration temperature and drying shrinkage length of SWP-HR added cement mortar had a tendency to decrease compared to those of cement mortar without SWP-HR addition. Also, it was confirmed through crack pattern experiment of plate-form specimen for elucidating crack-reducing characteristic that anti-crack property of SWP-HR added cement mortar was improved.

Reduction of Hydration heat of FA concrete using Coal Gasification Slag for Mixed Fine Aggregate (석탄 가스화 용융 슬래그를 혼합 잔골재로 사용한 FA 치환 콘크리트의 수화열 저감)

  • Han, Jun-Hui;Lee, Young-Jun;Choi, Il-Kyung;Kim, Jung;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2019.11a
    • /
    • pp.79-80
    • /
    • 2019
  • This study was intended to examine the possibility of reducing hydration heat by FA substitution and combination of slag (CGS) from coal gasification power generation (IGCC) with mixed aggregate for concrete. The analysis results showed good results if liquidity increases as the ratio of CGS increases, air volume decreases, and compressive strength is mixed up to 25% in the residual aggregate. The results showed that the heat of hydration was reduced compared to plain due to the boron content of CGS as the CGS substitution rate increased, but it was larger due to the combination with FA substitution. It was found that the heat of hydration was reduced.

  • PDF