• Journal of the Korea Concrete Institute
• /
• 제13권6호
• /
• pp.593-601
• /
• 2001

In RC structure, sufficient anchorage of reinforcement is necessary for the member to produce the full strength. Generally, conventional standard hook is used for the reinforcement's anchorage. However, the use of standard hook results in steel congestion, making fabrication and construction difficult. Mechanical anchor offers a potential solution to these problems and may also ease fabrication, construction and concrete placement. In this paper, the required characteristics and the design considerations of mechanical anchor were studied. Also, the mechanical anchor was designed according to the requirements. To investigate the pull-out behavior and properness of mechanical anchorage, pull-out tests were performed. The parameters of tests were embedment length, diameter of reinforcement, concrete compressive strength, and spacing of reinforcements. The strengths of mechanical anchor were consistent with the predictions by CCD method. The slip between mechanical anchor and concrete could be controlled under 0.2mm. Therefore, the mechanical anchor with adequate embedment could be used for reinforcement's anchorage. However, it was observed that the strength of mechanical anchors with short spacing of reinforcements was greatly reduced. To apply the mechanical anchor in practice (e.g. anchorage of the beams reinforcements in beam-column joint), other effects that affect the mechanical anchor mechanism, such as confinement effect of adjacent member from frame action or effects of shear reinforcement, should be considered.

• 월간 기계설비
• /
• 통권53호
• /
• pp.68-83
• /
• 1994

해외건설업의 경영은 지리적$\cdot$문화적 차이, 환경의 다양성, 통제불가능 변수의 존재 등 여러 가지의 불확실성 등으로 인해 국내에서의 건설업 경영보다 어려우며 그마만큼 현지화의 정착이 어렵다고 하겠다. 따라서 당해지역에 기진출 또는 진출하고자 하는 투자기업이 현지에서 국내 기업과 마찬가지로 하나의 기업으로 정착하여 현지에서의 경제적$\cdot$사회적$\cdot$정치적 변화에 능동적으로 대처하고 현지 사회와의 조화로운 성장을 도모할 수 있도록 하는 것이 현지화가 바라는 궁극적인 목적이 되겠다. 이에따라 우리 기업이 해외시장에 현지화를 도모하기 위해서는 현지의 관습, 문화 등을 충분히 숙지하고 거기에 알맞는 제반 경영관리 기법을 개발하는 등 국제 경영능력을 배양하지 않으면 안된다. 이것이 바로 현지화와 직결되는 과제라고 할수 있겠다. 이에 해외건설협회와 경제연구소에서는 해외건설진흥기금 지원사업의 일환으로 건설업 개별기업이 해외 현지화를 정착시키는데 일조가 되고자 $\ulcorner$해외건설의 현지화 정착 방안$\lrcorner$을 마련하였다. 이 내용을 본지에서는 발췌$\cdot$정리, 게재하여 해외 진출에 뜻이 있는 우리 설비업계에 도움을 주고자 한다.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 한국안전학회 1999년도 춘계 학술논문발표회 논문집
• /
• pp.163-168
• /
• 1999

Post-Tensioning System은 강선(Strand)을 긴장하여 콘크리트 부재에 미리 압축력을 주어 응력을 도입시키기 위한 텐던(Tendon)과 정착구(Anchorage)의 조합체계로서 이루어진다. 여기서 텐던이란 와이어, 스트랜드, 바아등의 긴장재의 하나 혹은 여러개의 묶음을 의미하며, 정착구란 긴장된 텐던에 발생된 힘을 지탱하여 그 힘을 콘크리트에 전달해 주는 기계적 장치를 말하며 콘과 Wedge로 구성된다. (중략)

• Journal of the Korea institute for structural maintenance and inspection
• /
• 제23권5호
• /
• pp.111-117
• /
• 2019

Shear experiments were carried out to evaluate shear performance of SFRC deep beams with end-anchorage of SD600 high strength headed reinforcing tensile bars. The experimental variables include the end-anchorage methods of tensile bars (headed bar, straight bar), the end-anchorage lengths, and the presence of shear reinforcement. Specimens with a shear span ratio of 1 showed a pattern of the shear compression failure with the slope cracks progressed after the initial bending crack occurred. Specimens with end-anchorage of headed bars (H-specimens) showed a larger shear strengths of 5.6% to 22.4% compared to straight bars (NH-specimens). For H-specimens, bearing stress reached 0.9 to 17.2% of the total stress of tensile bars up to 75% of the maximum load, and reached 22.4% to 46%. This shows that the anchorage strength due to the bearing stress of headed bars has a significant effect on shear strength. The experimental shear strength was 2.68 to 4.65 times the theoretical shear strength by the practical method, and the practical method was evaluated as the safety side.

• Magazine of the Korea Concrete Institute
• /
• 제13권1호
• /
• pp.26-30
• /
• 2001

• Journal of Korean Society of Steel Construction
• /
• 제26권1호
• /
• pp.1-10
• /
• 2014

In this study, out-of-plane flexural test was performed to analyze behavior properties for a beam specimen which imitated a structure with connection member between reinforced concrete and steel plate concrete part. Tie bars between a upper and a lower steel plate, and tie wide flange shapes between upper and lower ribs were designed to prevent the steel plate or the ribs from breakaway in the connection of the specimen. As a result of the test, ductile failure behavior of the specimen and the functionality of the tie members were conformed as originally intended. Also, tension tests were performed to evaluate the design appropriateness of two specimens produced to anchor and connect mechanically #14 bars. The two test results showed that the anchorage connection system behaves in elastic limit during the main bars yielded, and the integrity of the designed system was verified.

• Journal of the Korean Geotechnical Society
• /
• 제33권10호
• /
• pp.59-69
• /
• 2017

The tension load of the ground anchor inserted in the ground gradually changes over time. In this regard the change of the initial tension load is primarily decreased by the fixation condition of the fixing head and the mechanical characteristics of the tensile material. The subsequent additional tension load is a time-dependent loss mostly due to the fixing conditions of the bonded length and the surrounding ground properties of the field. In this paper, therefore, a measurement system using a relative displacement detector that can relatively easily measure the change of tension load is discussed. As a result of the review, it was confirmed that the results using the relative displacement detector are similar to those of the real scale model test, and it was also confirmed that similar results were obtained with the result of the pull-out test conducted on the ground anchors fixed to weathered rocks condition. In addition, a pull-out test was conducted on the test anchors whose initial tension load loss was relatively large and through this test pull-out behavior of the tension type ground anchors was verified.

• 월간 기계설비
• /
• 제11호통권220호
• /
• pp.38-38
• /
• 2008

일본 일본공조위생공사업협회는 지난 5월 288일 창립 70주년을 기념하는 제60회 통상총회를 열고 2008년도 사업계획을 발표했다. 이 중 우리의 관심을 끄는 것은 기획총무부문의 설비공사의 직접발주(분리발주)에 대한 주장이다. 일본 공조위생공사업협회는 국가, 지방자치단체, 독립행정법인, 민간발주자 등에 대하여 설비업계의 적극적인 홍보활동을 전개하면서 특히 민간발주자에게 "설비는, 전문가인 설비공사업자에게 직접 발주하여 주십시오!"라는 주장을 펼치기로 했다. 또한 건설업계에 "직접발주(분리발주)"라는 용어의 정착을 추진키로 했다. 우리에게 원 하도급 간에 계열화가 정착된 것으로 알려진 일본은 공공공사에서는 분리발주가 정착되었으나 민간발주 부문에서는 아직도 분리발주가 완전히 실현되지 않고 있어서 이같은 사업을 추진하고 있는 것으로 보여진다. 따라서 일본 공조위생공사업협회는 민간공사에서도 절대적으로 분리발주 해 줄 것을 요구하는 슬로건을 내세우고 있으며, 더 나아가 100% 분리발주 확대 추진을 목표로 하고 있다. 다음은 일본공조위생공사협회가 총회에서 채택한 슬로건이다.

• Journal of the Korea Concrete Institute
• /
• 제14권3호
• /
• pp.430-439
• /
• 2002

The development of reinforcing steel is required in reinforced concrete structures. The standard hooks that have been widely used for the tensile development in the beam-column joints tend to create difficulties of construction such as steel congestion as the member cross sections are becoming smaller due to the use of higher strength concrete and higher grade steel. Using the reinforcing bars with end mechanical anchoring device (headed reinforcement) provides potential economies in construction such as reduction in development lengths, simplified details, and improved responses to cyclic loadings. In this paper, the pullout strengths and behaviors of the headed reinforcement were experimentally studied. In 33 pullout tests performed using D25 deformed reinforcing bars, the test parameters were embedment depth, edge distance, head size, and the use of transverse reinforcement. The pullout strengths determined from tests closely agreed with the pullout strengths predicted using the CCD method. The pullout strengths increased with increasing embedment depths nd edge distances. The strengths tend to increase with the use of larger heads. From the experimental program where the effect of the transverse reinforcement was examined, a modification factor to the CCD was suggested to represent the effect of such reinforcement that is installed across the concrete failure plane on the pullout strengths.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 한국농업기계학회 2003년도 하계 학술대회 논문집
• /
• pp.65-105
• /
• 2003

농업기계학이 대학에서 독자적인 학과로 정착된 지 33년이 지났고, 농업기계학회가 창립된지도 올해로 27년을 맞았다. 그동안 우리나라가 이룩한 농업기계화는 비록 벼농사에 국한되기는 하지만, 국내외로부터 짧은 기간동안에 세계에서 가장 성공적이었다고 평가받고 있다. 이 같은 배경에는 무엇보다도 1978년도에 제정된 농업기계화촉진법의 역할이 컸다고 볼 수 있다. 즉 이를 계기로 대학에 학과가 증설되고 농촌진흥청 농업기계화연구소가 발족되었을 뿐만 아니라, 지난 25년 동안 시대상황에 알맞은 정부의 농업기계화 정책의 수립과 산학연의 농업기계 연구개발ㆍ생산ㆍ보급ㆍ유통ㆍ사후봉사 등 노력의 결과로 현재와 같은 농업기계화 기반이 마련되었다. (중략)