• 콘크리트학회논문집
• /
• 제27권4호
• /
• pp.387-397
• /
• 2015

본 연구에서는 시공성 향상을 위해 데크플레이트와 비정질강섬유 콘크리트를 적용하여 현장 무배근 슬래브 시스템을 연구하였다. 제안한 슬래브에서는 온도철근을 강섬유로 대체하였다. 본 연구는 연속슬래브에서 상부 철근이 연속되지 않는 경우 슬래브의 상부 균열 제어를 주로 고려하였다. 실험변수로 비정질강섬유 혼입량, 강섬유 종류, 데크플레이트 종류, 연속구간의 철근 이음을 고려하였으며, 수직하중을 받는 2경간 슬래브를 실험하였다. 슬래브의 균열저항성능을 평가하기 위하여 연속슬래브의 하중에 따른 균열폭을 계측하였다. 실험결과, 상부 이음철근을 사용하지 않더라도 합성슬래브의 높은 휨강성으로 인하여 균열을 억제할 수 있는 것으로 나타났다.

• 한국강구조학회 논문집
• /
• 제16권5호통권72호
• /
• pp.587-598
• /
• 2004

본 연구에서는 합성보의 전체 춤을 절감할 수 있도록 속 빈 프리캐스트 콘크리트 슬래브를 철골보의 춤내에 삽입하여 일체화함으로써 철골조 고층건물에서 층고를 최소화 할 수 있는 이른바 "슬림플로어"공법에 대한 연구를 수행하였다. 본 연구는 콘크리트에 매입된 비대칭 철골보를 가지는 불완전 합성 슬림플로어 시스템의 휨 거동에 관한 것이다. 총 10개의 실대형 실험체를 철골보 춤, 속빈 프리캐스트 콘크리트 슬래브 춤, 슬래브 유효폭, 및 콘크리트 슬래브의 지지방식 별로 제작하여 실험을 수행하였다. 실험결과, 매입형 합성보의 경우, 별도의 전단연결재를 설치하지 않아도 자체가 가지고 있는 기계적 화학적 부착응력으로 인해 완전합성보에 비해서 0.48~0.98의 전단합성비를 나타내었다.

• Steel and Composite Structures
• /
• 제24권2호
• /
• pp.177-189
• /
• 2017

Hybrid-fiber reinforced concrete (HFRC) may provide much higher tensile and flexural strengths, tensile ductility, and flexural toughness than normal concrete (NC). HFRC slab has outstanding advantages for use as a composite bridge potential deck slab owing to higher tensile strength, ductility and crack resistance. However, there is little information on shear connector associated with HFRC slabs. To investigate the mechanical behavior of the stud shear connectors embedded in HFRC slab, 14 push-out tests (five batches) in HFRC and NC were conducted. It was found that the stud shear connector embedded in HFRC had a better ductility, higher stiffness and a slightly larger shear bearing capacity than those in NC. The experimentally obtained ultimate resistances of the stud shear connectors were also compared against the equations provided by GB50017 2003, ACI 318-112011, AISC 2011, AASHTO LRFD 2010, PCI 2004, and EN 1994-1-1 (2004), and an empirical equation to predict the ultimate shear connector resistance considering the effect of the HFRC slabs was proposed and validated by the experimental data. Curve fitting was performed to find fitting parameters for all tested specimens and idealized load-slip models were obtained for the specimens with HFRC slabs.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.25-28
• /
• 2006

In general, post-installed dowel bars are used as a shear connector to ensure the composite actions between new slabs and existing slabs in an apartment remodelling constructions expecially for enlarging the interior space outward the existing buildings. But, it has not been checked that the connection performance between existing and new slab is satisfactory not only for the structural safety condition but also the for serviceability and dwelling requirements. In this research, an experimental works were presented to evaluate the load transfer capacity for the planar joints between existing and new slab. The existing slabs were obtained from the existing apartment housing which will be demolished, and were retrofitted with carbon fiber plate. Test results showed that the planar joints with post-installed dowel bars behaved in full composite modes until ultimate capacity of test specimens, so sufficient ultimate and serviceability performance are confirmed.

• Steel and Composite Structures
• /
• 제49권5호
• /
• pp.571-585
• /
• 2023

The application of relatively low volumes of fibres in normal strength concrete has been shown to be of significant benefit when applied to composite slabs with profiled sheet decking. This paper reports on an experimental study aimed at quantifying further potential benefits that may arise from applying ultra-high performance fibre reinforced concrete. To assess performance six simply supported beams were tested under hogging and sagging loading configurations along with three two span continuous beams. Fibre contents are varied from 0% to 2% and changes in strength, deformation, crack width and moment redistribution are measured. At the serviceability limit state, it is shown that the addition of high fibre volumes can significantly enhance member stiffness and reduce crack widths in all beams. At the ultimate limit state it is observed that a transition from 0% to 1% fibres significantly increases strength but that there is a maximum fibre volume beyond which no further increases in strength are possible. Conversely, member ductility and moment redistribution are shown to be strongly proportional to fibre volume.

• Structural Engineering and Mechanics
• /
• 제82권5호
• /
• pp.595-609
• /
• 2022

Prestressed composite steel-concrete beams are still a technology restricted to repair sites of large-scale structures and spans. One of the reasons for that is the absence of standard frameworks and publications regarding their design and implementation. In addition, the primary normative codes do not address this subject directly, which might be related to a scarcity of papers indicating methods of design that would align the two technics, composite beams and external prestressing. In this context, this paper proposes methods to analyze the sizing of prestressed composite beams submitted to pre-tension and post-tension with a straight or polynomial layout cable. This inquiry inspected a hundred and twenty models of prestressed composite beams according to its prestressing technology and the eccentricity and value of the prestressing force. The evaluation also included the ratio between span and height of the steel profile, thickness and typology of the concrete slab, and layout of the prestressing cables. As for the results, it was observed that the eccentricity of the prestressing force doesn't significantly influence the bending resistance. In prestressed composite beams subjected to a sagging moment, the ratio L/d can reach 35 and 30 for steel-concrete composite slabs and solid concrete slabs, respectively. Considering the negative bending moment resistance, the value of the L/d ratio must be less than or equal to 25, regardless of the type of slab. When it comes to the value of the prestressing force, a variation greater than 10% causes a 2.6% increase in the positive bending moment resistance and a 4% decrease in the negative bending moment resistance. The pre-tensioned composite beams showed a superior response to flexural-compression and excessive compression limit states than the post-tensioned ones.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
• /
• pp.293-298
• /
• 1995

The strength of shear connectors embedded in lightweight concrete slab with deck plate is influenced by various factors of deck plate, shear conncetor and concrete. Generally, it is reported that the strength of shear connector in lightweight concrete decreases in comparison with that in normal concrete. So this paper is to use compressive strength of lilghtweight concrete, width-height ratio of deck plate, and cross sectional area of shear conncetor as variables, to evaluate the strength of shear conncetors in composite beam of steel and lilghtweight concrete slabs with deck plate, and then to suggest the reasonable strength equation by comparing the push-out test results with establixhed strength formula. As the result of 24 specimens test, in case of lightweight concrete slab with deck plate, it has showed that in the same strength, the strength of shear connector decreased about 10~20% in comparison with that in normal concrete. In spite of lightweight concrete, the test results were closely approached the established strength formula of shear connector using Fisher's reduction coefficient.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
• /
• pp.548-555
• /
• 1998

The influences of high speed train on the dynamic responses of steel composite railway bridges are investigated. The bridge system which has two Ⅰ-girder and several cross beams is modeled with plate and frame elements. With assumption of concrete slabs ate fully connected with steel girders, the offset between slabs and girders is modeled using rigid link. The track system is modeled using beams on elastic foundation theory. And, the TGV train is modeled in 2-dimension considering bouncing and pitching motion. And, braking action of vehicle is considered using speed dependent braking function. To investigate the behavior of bridges due to moving trains, parametric studies are performed.

• 한국구조물진단유지관리공학회 논문집
• /
• 제22권5호
• /
• pp.64-71
• /
• 2018

본 연구는 방음재를 삽입한 새로운 개념의 합성슬래브 시스템을 제안하고, T-형 바의 폭, 전단보강 철근의 설치 등을 실험의 주요변수로 한 총 7개의 실험체를 제작 Push-Down실험방법으로 수행한 수평전단성능에 대한 실험 결과를 제공하고 있다. 실험결과 T-형 바를 전단키로 적용하고 방음재를 삽입한 실험체가 기본실험체에 비해 수평전단성능에서 2배 이상 우수한 것으로 나타났다. 이는 제안한 합성슬래브상세를 실제 현장 적용하여도 기존의 합성슬래브 보다 구조적 측면에서 상당한 안전율을 확보할 것으로 생각되며, 내진동 및 방차음의 개선에도 크게 기여할 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
• /
• pp.23-24
• /
• 2009

본 연구는 휨 재의 균열손상 특성을 개선하기 위하여 개발된 팽창형 SHCC의 구조적인 적용에 관한 기초연구이다. 본 논문에서는 총 4개의 단순 지지된 철근콘크리트 슬래브에 대한 실험결과를 근거로 하며 본 실험에서 고려된 변수는 SHCC 종류와 SHCC 두께이다. 이러한 실험변수에 따른 최대 휨 강도, 초기균열하중, 균열폭 및 간격 그리고 하중-변위 관계곡선에 대하여 비교 분석하여 각 실험변수 의 영향을 평가하였다.