• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.73-76
• /
• 2006

The shape and dimension of precast concrete structure used in habor construction(caisson, block, etc.) are considered productive facility abilities, demanded minimum dimension in work of each member, the relation between the depth of water and a location of leaving, work conditions of towing and leaving, after leaving, differential settlement, etc. As this study examined friction resistance effect of financially designed precast concrete structure formed convex in bottom and stone mound.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2022년도 가을 학술논문 발표대회
• /
• pp.211-212
• /
• 2022

In this study, the cracking control performance of ultra-low shrinkage concrete was investigated by the field application. As a result, drying shrinkage crack occurred in normal concrete wall, but no crack occurred in ultra-low shrinkage concrete wall. It is determined that the drying shrinkage crack control effect of the ultra-low shrinkage concrete is excellent.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.101-102
• /
• 2023

This study aims to mix the base concrete by mixing latex to improve the durability performance to reduce the composite deterioration of the base concrete. Latex fiber has high resistance to freezing and thawing, adhesion, and deicing agent (calcium chloride), and it is used to secure long-term durability to reduce cracking and compound deterioration of concrete. In addition, through experiments, we are trying to find ways to improve the strength of concrete by studying the mixing of the appropriate mixing ratio of latex.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.37-38
• /
• 2023

As one of the resource recovery projects, this study aims to select natural fibers and synthetic fibers that can be used for concrete mixing among waste fibers and reuse them for the base concrete mixture. Using waste fiber, we seek a solution to the problem of reduced fluidity and hardening time of fiber-reinforced concrete and find the optimal mix of the ground concrete mixed with waste fiber.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 가을학술발표대회논문집
• /
• pp.57-58
• /
• 2023

This study is to estimate cold weather concrete periods by analyzing data of Korea Meteorological Administration in terms of recently revised cold weather concrete regulation of Korea Concrete Institute.

• 한국건축시공학회지
• /
• 제10권6호
• /
• pp.7-17
• /
• 2010

현대 건설기술의 발달은 건설현장의 시스템화로 이어져 공법이 단순해졌다고는 하나 인력의존도가 높은 철근 콘크리트공사에서는 여전히 새로운 재해가 늘고 있으며 대형화 되고 있다. 본 연구는 철근콘크리트 공사를 중심으로 재해사례 및 원인을 조사하였다. 아울러 건설현장 관계자들을 대상으로 설문조사를 하여, 안전의식 및 재해발생과 관련한 근로자의 심리적 상태를 파악하였다. 그리고 건설현장의 재해와 관련된 기본적인 요인을 도출하여 각 요인들 간의 상관성을 분석하여 효율적 안전관리 방안을 위한 체크리스트를 제안 하였다. 본 연구의 수행으로 도출된 안전관리 체크리스트를 숙지하여 우선순위 유형을 안전관리의 도구로 활용하여 철근콘크리트 공사의 합리적인 안전관리를 수행하여야하며 단순히 통계의 분석으로 볼 것이 아니라 여기서 도출된 내용을 바탕으로 안전 교육시에 활용하고 연구하여 재해예방의 도구로 활용하여야 할 것이다.

• Geomechanics and Engineering
• /
• 제36권2호
• /
• pp.145-156
• /
• 2024

The mechanical properties of the concrete-frozen soil interface play a significant role in the stability and service performance of construction projects in cold regions. Current research mainly focuses on the precast concrete-frozen soil interface, with limited consideration for the more realistic cast-in-place concrete-frozen soil interface. The two construction methods result in completely different contact surface morphologies and exhibit significant differences in mechanical properties. Therefore, this study selects silty clay as the research object and conducts direct shear tests on the concrete-frozen soil interface under conditions of initial water content ranging from 12% to 24%, normal stress from 50 kPa to 300 kPa, and freezing temperature of -3℃. The results indicate that (1) both interface shear stress-displacement curves can be divided into three stages: rapid growth of shear stress, softening of shear stress after peak, and residual stability; (2) the peak strength of both interfaces increases initially and then decreases with an increase in water content, while residual strength is relatively less affected by water content; (3) peak strength and residual strength are linearly positively correlated with normal stress, and the strength of ice bonding is less affected by normal stress; (4) the mechanical properties of the cast-in-place concrete-frozen soil interface are significantly better than those of the precast concrete-frozen soil interface. However, when the water content is high, the former's mechanical performance deteriorates much more than the latter, leading to severe strength loss. Therefore, in practical engineering, cast-in-place concrete construction is preferred in cases of higher negative temperatures and lower water content, while precast concrete construction is considered in cases of lower negative temperatures and higher water content. This study provides reference for the construction of frozen soil-structure interface in cold regions and basic data support for improving the stability and service performance of cold region engineering.

• 한국건설관리학회논문집
• /
• 제6권5호
• /
• pp.119-127
• /
• 2005

최근의 건설시장 축소와 주 5일 근무제도, 공기단축형 입찰제도의 도입, 후분양제도의 도입 등의 제도적 변화에 따라 건설 수주 경쟁은 더욱 치열해지고 있다. 그러나 건설공사는 공기지 연을 유발하는 수많은 공정리스크가 존재하고 있으며 이러한 공정리스크에 대한 인식과 그에 따른 체계적인 관리가 부진한 경우 건설공사의 경쟁력을 확보하는 데 여러 어려움이 존재한다. 이러한 문제점을 해결하기 위한 기존 연구는 공정리스크의 분류, 공정 리스크의 관리, 리스크 관리를 위한 시스템 개발에 치중하였다. 이에 본 연구는 전체 공정에 영향력이 크며, 위험발생 확률이 높은 철근콘크리트공사를 대상공종으로 선정하고 기존연구를 바탕으로 수차례의 전문가 면담과 난상토론을 실시하여 현실적인 리스크 요인과 관리방안을 제시하였다.

• 한국건축시공학회지
• /
• 제19권6호
• /
• pp.503-510
• /
• 2019

최근 RC 구조물의 건설기술에서는 콘크리트의 크리프에 대한 검토가 이루어져야 한다. 본 연구에서는 콘크리트의 크리프 예측 및 국내 건설현장의 크리프 결과에 영향을 미치는 요인을 검토했다. 크리프 테스트 기간이 길고 압축 강도가 높을수록 크리프 예측 정확도가 높아졌다. 경화 온도가 높을수록 콘크리트의 초기 강도가 높아지지만 크리프 계수의 차이는 시간이 지남에 따라 증가했다. 국내 건설현장 및 실험실에서의 크리프 평가 결과를 기반으로 ACI-209모델을 보완하는 수정 된 예측 모델을 제안했다. 일반~고강도 콘크리트를 사용한 실제 부재의 크리프 예측에서는 테스트 기간과 온도를 정확하게 고려해야한다.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제56권1호
• /
• pp.101-118
• /
• 2017

In this article we study a reconstruction of mathematical knowledge on trigonometry by the method of ascent from the abstract to the concrete from the pedagogical viewpoint of dialectic. The direction of education is shifting in a way that emphasizes the active constitution of knowledge by the learning subjects from the perspective that knowledge is transferred from the teacher to the student. In mathematics education, active discussions on the construction of mathematical knowledge by learners have been going on since the late 1990s. In Korea, concepts and aspects of constructivism such as operational constructivism, radical constructivism, and social constructivism were introduced. However, examples of practical construction according to the direction of construction of mathematical knowledge are very hard to find. In this study, we discuss the direction of the actual construction of mathematical knowledge and suggest a concrete example of the actual construction of trigonometry knowledge from a constructivist point of view. In particular, we discuss the process of the construction of theoretical knowledge, the ascent from the abstract to the concrete, based on the literature study from the pedagogical viewpoint of dialectic, and show how to construct the mathematical knowledge on trigonometry by the method of ascent from the abstract to the concrete. Through this study, it is expected to introduce the new direction and new method of knowledge construction as 'the ascent from the abstract to the concrete', and to present the possibility of applying dialectic concepts to mathematics education.