• Steel and Composite Structures
• /
• 제9권4호
• /
• pp.349-366
• /
• 2009

The composite slim beam has become popular throughout Europe in recent years and has also been used on some projects in China. With its steel section encased in a concrete slab, the steel-concrete composite slim beam can provide the floor construction with minimum depth and high fire resistance. However, the design method of the T-shape steel-concrete composite beam is no longer applicable to the composite slim beam with deep deck for its special construction, of which the present design models are not available but mainly depend on experiences. The elevation of the flexural stiffness and bending capacity of composite slim beams with deep deck is rather complicated, because the influences of many factors should be taken into account, such as the variable section dimensions, development of cracks and non-linear characteristics of concrete, etc. In this paper, experimental investigations have been conducted into the flexural behavior of two specimens of simply supported composite slim beam with deep deck. The emphases were laid on the bonding force on the interface between steel beam and concrete, the stress distribution of beam section, the flexural stiffness and bending capacity of the composite beams. Based on the experimental results, the reduction factor of equivalent stress distribution in concrete flange is suggested, and the calculation method of flexural stiffness and bending capacity of simply supported slim beams are proposed.

• Steel and Composite Structures
• /
• 제26권4호
• /
• pp.485-499
• /
• 2018

In this paper, a hollow steel tube (HST) shear connector is proposed for use in a slim-floor system. The HST welded to a perforated steel beam web and embedded in concrete slab. A total of 10 push-out tests were conducted under static loading to investigate the mechanical behavior of the proposed HST connector. The variables were the shapes (circular, square and rectangular) and sizes of hollow steel tubes, and the compressive strength of the concrete. The failure mode was recorded as: concrete slab compressive failure under the steel tube and concrete tensile splitting failure, where no failure occurred in the HST. Test results show that the square shape HST in filled via concrete strength 40 MPa carried the highest shear load value, showing three times more than the reference specimens. It also recorded less slip behavior, and less compressive failure mode in concrete underneath the square hollow connector in comparison with the circular and rectangular HST connectors in both concrete strengths. The rectangular HST shows a 20% higher shear resistance with a longer width in the load direction in comparison with that in the smaller dimension. The energy absorption capacity values showed 23% and 18% improvements with the square HST rather than a headed shear stud when embedded in concrete strengths of 25 MPa and 40 MPa, respectively. Moreover, an analytical method was proposed and predicts the shear resistance of the HST shear connectors with a standard deviation of 0.14 considering the shape and size of the connectors.

• 한국산학기술학회논문지
• /
• 제19권3호
• /
• pp.130-140
• /
• 2018

U형 강재보를 근간으로 콘크리트 슬래브와 합성을 위하여 A형의 덮개형 강재앵커를 검토하여 AU합성보를 연구하였다. 이는 노출형의 H형강 강재보에 비해 내부 평면의 자율성을 높일 수 있고 공기 단축과 더불어 층고 절감이 가능하며 튜브구조로서 내부에 콘크리틀 충전하여 휨 강도과 휨 강성를 높였다. 본 연구에서는 AU합성보의 휨실험을 통해 성능을 평가하였다. 실험 결과, 하중 초기에 선형적으로 하중이 증가하면서 콘크리트 슬래브의 파괴에 의해 최대 강도에 도달하고 최대 내력의 85% 이상을 발휘하며 연성적 거동을 하였다. 또한, 덮개형 강재앵커를 통해 합성효과를 발휘하였으며 모든 실험체가 최대 내력에 도달할 때까지 완전 합성거동으로 안정적이었다. 그리고 U형 단면의 강판 두께를 증가시켰을 경우에도 휨 강도와 휨 강성이 증가하였고, U형 단면의 하부에 고강도 강판을 용접 부착하였을 경우에도 성능이 개선되었다. AU합성보의 휨강도는 건축구조기준에 따라 제안된 휨 강도식을 적용할 수 있을 것으로 판단되었다.