• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.199-200
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• 2021

In the study, creep and dry shrinkage characteristics were evaluated to determine the material properties necessary for structural analysis such as column shortening and differential drying shrinkage. All the experiments were conducted in an constant temperature and humidity room. The mechanical properties as well as the specific creep and ultimate dry shrinkage values were derived. In addition the characteristics of the physical value of the high-strength fiber reinforced concrete were considered.

• 한국구조물진단유지관리공학회 논문집
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• 제10권5호
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• pp.106-114
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• 2006

본 연구는 개발된 저수축 고성능 콘크리트를 대상으로 모의부재 시험체에 있어서 콘크리트의 기초적 물성과 수축특성에 대하여 검토한 것이다. 실험연구 결과, 콘크리트의 배합특성으로 제안 배합은 목표 슬럼프플로우 및 목표 공기량을 만족하기 위해 SP제량 증가, AE제량 감소의 배합보정이 필요하였다. 응결시간은 제안 배합이 8시간 정도 빠르게 나타났으며, 굳은 콘크리트의 압축강도는 60MPa 이상의 고강도로 나타냈다. 수축특성으로 제안 배합 자기수축의 경우 플레인 배합 자기수축에 비해 50% 정도 저감되었고, 제안 배합의 중심부 건조수축은 수분발산이 없는 것에 기인하여 자기수축과 유사한 경향이었으나, 표면부는 크게 수축하였다. 단, 철근배근 시험체인 경우는 철근구속에 의해 내부 및 표면의 수축량이 작게 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제23권5호
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• pp.104-110
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• 2019

콘크리트는 시멘트와 골재를 포함한 복합재료로써 건조 수축이라는 특성을 가지고 있으며, 이에 대하여 많은 연구가 콘크리트를 균질재료로 가정하여 수행되어 왔다. 그러나, 수축은 콘크리트를 구성하는 특정 구성 성분에만 작용하는 현상이기 때문에 기존의 평균화된 유효물성(effective properties)의 개념으로 규명하기에는 어려움이 있다. 따라서, 본 논문에서는 콘크리트의 특징적인 거동 중의 하나이며 지금까지 많은 연구들이 수행되어 왔지만, 아직 불확실성이 많은 콘크리트의 수축 현상을 비균질성을 고려한 전산해석(heterogeneous simulation)을 통해 분석하는 방법을 제안하였다. 골재와 모르타르를 별도로 모델링하는 메소모델을 이용하여 모르타르에만 수축 변형을 가하는 방법으로 콘크리트의 수축 해석을 수행하였다. 해석 결과에 따르면 콘크리트의 수축에 의한 균열 발생은 골재의 강성과 부재의 구속도에 의해 크게 영향을 받는 것을 알 수 있었다. 또한, 수축에 의한 콘크리트의 균열발생은 단순한 하나의 값으로 나타내지 못하는 현상이며, 골재의 강성과 부재의 구속도는 그에 큰 영향을 주는 요소들이었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.385-386
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• 2010

본 논문은 석회석 미분말을 활용한 고유동 콘크리트의 유동 특성 및 자기수축량을 통하여 자기수축 특성을 알아보았다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.131-134
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• 1990

Many papers have been published on drying shrinkage of hardened cement paste and cement mortar. The causes of drying shrinkage in cement mortar may be attributed to its mechanical properties, temperature, curing time and the evaporation of water from cement mortar. This paper deals only with drying shrinkage in cement mortar. In particular, the relationships between water evaporation and drying shrinkage are discussed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.592-595
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• 2004

This Study discusses the properties of drying shrinkage of concrete slab with W/B, water content, fiber and anti-shrinkage agent. According to results, drying shrinkage is reduced with decrease of water content and W/B. Also, compared with plain concrete, drying shrinkage is reduced by using of fiber, anti-shrinkage agent and adding ratio of anti - shrinkage agent. Therefore, in the range of workability if water content and W/B are reduced and using of fiber and anti-shrinkage agent are performed properly, crack by drying shrinkage can be prevented effectively.

• International Journal of Concrete Structures and Materials
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• 제6권4호
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• pp.221-230
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• 2012

Cracking of repair material due to restraint of shrinkage could hinder the intended extension of serviceability of repaired concrete structure. The availability of model to predict shrinkage stress under restraint condition will be useful to assess whether repair material with particular deformation properties is resistance to cracking or not. The accuracy in the prediction will depend upon reliability of the model, input parameters, testing methods used to characterize the input parameters, etc. This paper reviews a variety of models to predict shrinkage stress in patch repair system. Effect of creep and composite action to release shrinkage stress in the patch repair system are quantified and discussed. Accuracy of the models is examined by comparing predicted and measured shrinkage stress. Simplified model to estimate shrinkage stress is proposed which requires only shrinkage property of repair material as an input parameter.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.175-180
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• 1999

The heating system of korea apartment house is called Ondol. The surface finishing mortar of this floor system typically used the cement based mortar, where the surface finishing mortar easily appears the crack. To order to crack control, the cement that added expansive additive used to reducing dry-shrinkage. For the surface finishing mortar, the types of shrinkage is known as plastic shrinkage, dry-shrinkage and autogenous This experimental study is to investigate the difference on dry-shrinkage of the cement that added expansive additives and OPC. The test method is varied the ration of water/cement (W/C) and the ratio of sand/cement(S/C). For OPC, The increase of the ratio of S/C is reduced dry-shirnkage but for the cement that added expansive additives, the increase of the ratio of S/C is augmented dry-shrinkage For OPC, The increase of the ratio of W/C is augmented dry-shrinkage but for the cement that added expensive, the increased of the ratio of W/C is reduced dry-shrinkage.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.473-476
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• 2003

This study discusses the use of anti-shrinkage agent as the method to reduce autogenous and drying shrinkage. According to results, as for the fundamental properties of high performance concrete, fluidity and strength decrease with an increase of the adding ratio of anti-shrinkage agent, but air content increases. Compared with plain concrete, autogenous and drying shrinkage are reduced by 12~52% and 4~22% respectively upto the adding rario of anti-shrinkage agent of 2.0%. When expansive additive is added by 5.0%, they are also reduced by 38~95% and 15~50% respectively. Therefore, as expansive additive of 5.0% and anti-shrinkage agent of 1.0% are added to high performance concrete of around W/B 30%, it is considered that fluidity and strength are hardly influenced, and in addition, crack by shrinkage can be prevented effectively.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.151-152
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• 2016

In this study, the shrinkage properties of concrete with the high-performance shrinkage admixture and the crack reinforcing materials applied to the high-flatness flooring of hypermarkets, outlets and warehouses was evaluated. The concrete with the popular shrinkage admixture is significantly reduced compared to the plain concrete without shrinkage admixture for the dry shrinkage deformation, and the difference of shrinkage ratio between the concretes has been shown to increase with increasing age.