• Title, Summary, Keyword: steel-concrete composite

Search Result 1,444, Processing Time 0.032 seconds

Experimental research on sagging bending resistance of steel sheeting-styrofoam-concrete composite sandwich slabs

  • Cao, P.Z.;Lu, Y.F.;Wu, Kai
    • Steel and Composite Structures
    • /
    • v.15 no.4
    • /
    • pp.425-438
    • /
    • 2013
  • A new-styrofoam-concrete composite sandwich slab with function of heat insulation is designed. Four full-scale simply supported composite sandwich slabs with different shear connectors are tested. Parameters under study are the thickness of the concrete, the height of profiled steel sheeting, the influence of shear connectors including the steel bars and self-drilling screws. Experimental results showing that four specimens mainly failed in bending failure mode; the shear connectors can limit the longitudinal slippery between the steel profiled sheeting and the concrete effectively and thus guarantee the good composite action and cooperative behavior of two materials. The ultimate sagging bending resistance can be determined based on plastic theory. This new composite sandwich slab has high sagging bending resistance and good ductility. Additionally, these test results help the design and application of this new type of composite sandwich slab.

Shear Strength of Steel Fiber Concrete - Plain Concrete Composite Beams (강섬유보강 콘크리트와 일반 콘크리트 합성보의 전단강도)

  • Kim, Chul-Goo;Park, Hong-Gun;Hong, Geon-Ho;Kang, Su-Min
    • Journal of the Korea Concrete Institute
    • /
    • v.27 no.5
    • /
    • pp.501-510
    • /
    • 2015
  • Composite construction of precast concrete and cast-in-place concrete is currently used for the modular construction. In this case, the use of steel fiber reinforced concrete (SFRC) could be beneficial for precast concrete. However, the shear strength of such composite members (SFRC and cast-in-place concrete) is not clearly defined in current design codes. In the present study, steel fiber composite beam tests were conducted to evaluate the effect of steel fibers on the composite members. The test variables are the area ratio of SFRC and shear reinforcement ratio. The test results showed that when minimum horizontal shear reinforcement was used, the shear strength of composite beams increased in proportion to the area ratio of steel fiber reinforced concrete. However, because of the steel fiber, the composite beams were susceptible to horizontal shear failure. Thus, minimum horizontal shear reinforcement is required for SFRC composite beams.

Influence of post-pouring joint on long-term performance of steel-concrete composite beam

  • Huang, Dunwen;Wei, Jun;Liu, Xiaochun;Zhang, Shizhuo;Chen, Tao
    • Steel and Composite Structures
    • /
    • v.28 no.1
    • /
    • pp.39-49
    • /
    • 2018
  • The concrete bridge decks are usually precast and in-situ assembled with steel girders with post-pouring joint in the construction practice of super-wide steel-concrete composite beam. But the difference of concrete age between the precast slabs and the post-pouring joint has been not yet considered for the long-term performance analysis of this kind composite beam. A simply supported precast-assembled T-shaped beam was taken as an example to analyze the long-term performance of steel-concrete composite beam with post-pouring joint. Based on the deformation coordination conditions of the old-new concrete deck and steel girder, a theoretical model for the long-term behavior of precast-assembled composite beam is proposed in this paper according to age-adjusted effective modulus method. Then, the feasibility of the proposed model is verified by the available test data from the Gilbert's composite beams. Parametric studies were preformed to evaluate the influences of the cross-sectional area ratio of the post-pouring joint to the whole bridge deck, as well as the difference of concrete age between the precast slabs and the post-pouring joint, on the long-term performance of the composite beam. The results indicate that the traditional method without considering the age difference would seriously underestimate the effect of creep and shrinkage of concrete bridge decks. The concrete age difference between the precast slabs and the post-pouring joint should be demonstrated for the life cycle design and long-term performance analysis of precast-assembled steel-concrete composite beams.

Finite element response sensitivity analysis of continuous steel-concrete composite girders

  • Zona, Alessandro;Barbato, Michele;Conte, Joel P.
    • Steel and Composite Structures
    • /
    • v.6 no.3
    • /
    • pp.183-202
    • /
    • 2006
  • The behavior of steel-concrete composite beams is strongly influenced by the type of shear connection between the steel beam and the concrete slab. For accurate analytical predictions, the structural model must account for the interlayer slip between these two components. This paper focuses on a procedure for response sensitivity analysis using state-of-the-art finite elements for composite beams with deformable shear connection. Monotonic and cyclic loading cases are considered. Realistic cyclic uniaxial constitutive laws are adopted for the steel and concrete materials as well as for the shear connection. The finite element response sensitivity analysis is performed according to the Direct Differentiation Method (DDM); its analytical derivation and computer implementation are validated through Forward Finite Difference (FFD) analysis. Sensitivity analysis results are used to gain insight into the effect and relative importance of the various material parameters in regards to the nonlinear monotonic and cyclic response of continuous composite beams, which are commonly used in bridge construction.

Mechanical characteristics of hollow shear connectors under direct shear force

  • Uenaka, Kojiro;Higashiyama, Hiroshi
    • Steel and Composite Structures
    • /
    • v.18 no.2
    • /
    • pp.467-480
    • /
    • 2015
  • The steel-concrete composite decks have high fatigue durability and deformability in comparison with ordinary RC slabs. Withal, the steel-concrete composite deck is mostly heavier than the RC slabs. We have proposed herein a new type of steel-concrete composite deck which is lighter than the typical steel-concrete composite decks. This can be achieved by arranging hollow sectional members as shear connectors, namely, half-pipe or channel shear connectors. The present study aims to experimentally investigate mechanical characteristics of the half-pipe shear connectors under the direct shear force. The shear bond capacity and deformability of the half-pipe shear connectors are strongly affected by the thickness-to-diameter ratio. Additionally, the shear strengths of the hollow shear connectors (i.e. the half-pipe and the channel shear connectors) are compared. Furthermore, shear capacities of the hollow shear connectors equivalent to headed stud connectors are also discussed.

Bond-slip effect in steel-concrete composite flexural members: Part 2 - Improvement of shear stud spacing in SCP

  • Lee, WonHo;Kwak, Hyo-Gyoung;Kim, Joung Rae
    • Steel and Composite Structures
    • /
    • v.32 no.4
    • /
    • pp.549-557
    • /
    • 2019
  • The use of shear studs usually placed in the form of mechanical shear connectors makes it possible to adopt composite steel-concrete structures in various structures, and steel-concrete plate composite (SCP) is being seriously considered for the installation of storage tanks exposed to harsh environments. However, manufacturing of SCP must be based on the application of existing design guidelines which require very close arrangement of shear studs. This means that the direct application of current design guidelines usually produces very conservative results and close arrangement of shear studs precludes pouring concrete within exterior steel faceplates. In this light, an improved guideline to determine the stud spacing should be introduced, and this paper proposes an improved ratio of the stud spacing to the thickness of steel plate on the basis of numerous parametric studies to evaluate the relative influence of the stud spacing on the stability of the SCP.

Static push-out test on steel and recycled tire rubber-filled concrete composite beams

  • Han, Qing-Hua;Xu, Jie;Xing, Ying;Li, Zi-Lin
    • Steel and Composite Structures
    • /
    • v.19 no.4
    • /
    • pp.843-860
    • /
    • 2015
  • Recycled tire rubber-filled concrete (RRFC) is employed into the steel-concrete composite structures due to its good ductility and crack resistance. Push-out tests were conducted to investigate the static behavior of steel and rubber-filled concrete composite beam with different rubber mixed concrete and studs. The results of the experimental investigations show that large studs lead a higher ultimate strength but worse ductility in normal concrete. Rubber particles in RRFC were shown to have little effect on shear strength when the compressive strength was equal to that of normal concrete, but can have a better ductility for studs in rubber-filled concrete. This improvement is more obvious for the composite beam with large stud to make good use of the high strength. Besides that the uplift of concrete slabs can be increased and the quantity and width of cracks can be reduced by RRFC efficiently. Based on the test result, a modified empirical equation of ultimate slip was proposed to take not only the compressive strength, but also the ductility of the concrete into consideration.

Compressive behavior of profiled double skin composite wall

  • Qin, Ying;Li, Yong-Wei;Su, Yu-Sen;Lan, Xu-Zhao;Wu, Yuan-De;Wang, Xiang-Yu
    • Steel and Composite Structures
    • /
    • v.30 no.5
    • /
    • pp.405-416
    • /
    • 2019
  • Profiled composite slab has been widely used in civil engineering due to its structural merits. The extension of this concept to the bearing wall forms the profiled composite wall, which consists of two external profiled steel plates and infill concrete. This paper investigates the structural behavior of this type of wall under axial compression. A series of compression tests on profiled composite walls consisting of varied types of profiled steel plate and edge confinement have been carried out. The test results are evaluated in terms of failure modes, load-axial displacement curves, strength index, ductility ratio, and load-strain response. It is found that the type of profiled steel plate has influence on the axial capacity and strength index, while edge confinement affects the failure mode and ductility. The test data are compared with the predictions by modern codes such as AISC 360, BS EN 1994-1-1, and CECS 159. It shows that BS EN 1994-1-1 and CECS 159 significantly overestimate the actual compressive capacity of profiled composite walls, while AISC 360 offers reasonable predictions. A method is then proposed, which takes into account the local buckling of profiled steel plates and the reduction in the concrete resistance due to profiling. The predictions show good correlation with the test results.

Experimental and numerical study on shear studs connecting steel girder and precast concrete deck

  • Xia, Ye;Chen, Limu;Ma, Haiying;Su, Dan
    • Structural Engineering and Mechanics
    • /
    • v.71 no.4
    • /
    • pp.433-444
    • /
    • 2019
  • Shear studs are often used to connect steel girders and concrete deck to form a composite bridge system. The application of precast concrete deck to steel-concrete composite bridges can improve the strength of decks and reduce the shrinkage and creep effect on the long-term behavior of structures. How to ensure the connection between steel girders and concrete deck directly influences the composite behavior between steel girder and precast concrete deck as well as the behavior of the structure system. Compared with traditional multi-I girder systems, a twin-I girder composite bridge system is more simplified but may lead to additional requirements on the shear studs connecting steel girders and decks due to the larger girder spacing. Up to date, only very limited quantity of researches has been conducted regarding the behavior of shear studs on twin-I girder bridge systems. One convenient way for steel composite bridge system is to cast concrete deck in place with shear studs uniformly-distributed along the span direction. For steel composite bridge system using precast concrete deck, voids are included in the precast concrete deck segments, and they are casted with cast-in-place concrete after the concrete segments are erected. In this paper, several sets of push-out tests are conducted, which are used to investigate the heavier of shear studs within the voids in the precast concrete deck. The test data are analyzed and compared with those from finite element models. A simplified shear stud model is proposed using a beam element instead of solid elements. It is used in the finite element model analyses of the twin-I girder composite bridge system to relieve the computational efforts of the shear studs. Additionally, a parametric study is developed to find the effects of void size, void spacing, and shear stud diameter and spacing. Finally, the recommendations are given for the design of precast deck using void for twin I-girder bridge systems.

Evaluation on compressive strength of steel-concrete composite piles using a large scaled UTM(Universal Test Machine) (대형 UTM을 이용한 강관합성 말뚝재료의 강도 특성 평가)

  • Lee, Ju-Hyung;Kwon, Hyung-Min;Park, Jae-Hyun;Kwak, Ki-Seok;Chung, Moon-Kyung
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.482-489
    • /
    • 2009
  • Various model piles with different sections such as reinforced concrete, steel, steel-concrete composite without rebar and steel-concrete composite with rebar were made, and vertical load test was conducted using a large scaled UTM(Universal Test Machine) to evaluate Young's modulus and ultimate load of the model piles. Based on the tests, ultimate load of steel-concrete composite pile is 31% greater than the sum of it of reinforced concrete pile and it of steel pile. This is caused that ultimate load and Young's modulus of inner concrete increase due to confining effect by outer steel casing. Variation of ultimate load is also insignificant depending on the ratio of length to diameter(L/D), therefore bucking has not an effect on change of ultimate load in case of the L/D below 10.

  • PDF