http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
배백일(Bae Baek-Il),손종민(Son Jong-Min),최창식(Choi Chang-Sik),최현기(Choi Hyun-Ki) 대한건축학회 2012 大韓建築學會論文集 : 構造系 Vol.28 No.5
In this study, experiments on ultra-high-strength steel fiber reinforced concrete beams with 2% volume fraction of steel fiber had been conducted. Test was conducted by two point loading with 2,000kN actuator for slender beam specimen. Shear-span to depth ratio was 6 intending the flexural failure. For the flexural design of ultra-high strength fiber reinforced concrete member an empirical equation had been proposed. Improving accuracy of empirical equation, 9 possible stress distributions for concrete section was compared with test results. For the reliability of empirical equation, these models were compared with experiment results conducted with previous researches. As a results of comparative study, the most exact solution was the model that use the real stress distribution of ultra-high strength fiber reinforced concrete. However, more safer prediction was possible using stress block parameters that was proposed by the study results of ultra-high strength concrete and tensile stress distribution that was considered the debonding properties of fiber.
ECC로 보강한 조적벽체의 전단성능에 관한 실험적 연구
배백일(Bae Baek-Il),박병규(Park Byung-Kyu),최현기(Choi Hyun-Ki),최창식(Choi Chang-Sik) 대한건축학회 2009 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.29 No.1(구조계)
In order to performing remodeling or change the usage of building, URM walls which used commonly in apartment as non-structural element need to have reliable performance of buildings because removal of this types of wall could make more wastes in construction site and removal procedure may cause delay of construction. Using normal shotcrete, as retrofitting method, cannot improve ductility and may cause brittle failure of structure. However, recent study for new materials, such as ECC or UHPC, can solve these problems increasing ductility and toughness of retrofitting materials. In this study, we used sprayed ECCs for retrofitting URM wall. ECCs can be designed to work in conjunction with existing walls to increase both strength and ductility for in-plane behavior of the URM wall. And this may change non-structural masonry wall to structural wall. To ensure that this technique will perform its intended purpose, in-plane lateral loading test was performed. The results of lateral load test of two retrofitted URM compared to non-retrofitted one. Retrofitted walls are consisted of just sprayed and anchored to wall base, RTM-ECC and have wiremesh, same detail of others, RTM-ECC-WM. Retrofitted specimens show significant increase of strength, ductility and energy dissipation capacity compared to URM. RTM-ECC show stiff strength degradation however, RTM-ECC-WM show slow degradation of strength because of the load transferring effect of wiremesh.
반응성 분체 콘크리트(RPC) 부재의 직사각형 응력블록 계수
배백일(Bae, Baek-Il),최현기(Choi, Hyun-Ki),최창식(Choi, Chang-Sik) 대한건축학회 2012 大韓建築學會論文集 : 構造系 Vol.28 No.7
In this paper, an experimental investigation of six steel fiber reinforced reactive powder concrete(RPC) columns was carried out deriving the appropriate design parameters of flexural induced columns with very high strength of concrete. Tested specimens have 200 mm square cross sections. Two of four specimens have rebars with 400MPa yield strength and another two specimens have no rebars. The RPC mix contains 2% of 0.2mm diameter by 13mm long straight steel fibres with concrete strength ranging from 100 to 200 MPa. Columns were induced to the flexural load by specially designed moment arm located at the end of columns with 10,000kN UTM. From the experimental data on the axial load, moment and strains along the longitudinal direction of columns, we could aware of the stress block of RPC with ultra high strength of concrete would be had a lower value than we use before. Test values represented that rectangular stress block parameter of ultra-shigh strength concrete was comparatively lower than values from the code provisions for concrete structure. For the more reliable calculating for stress block parameters of ultra-high strength concrete, existing test data of stress block parameter were investigated and regression analysis was carried out proposing new equation of rectangular stress block parameter α₁ and β₁ .