• Title/Summary/Keyword: Encased Composite Beams

Search Result 34, Processing Time 0.023 seconds

Flexural Capacity of the Profiled Steel Composite Beams -Deep Deck Plate- (강판성형 합성보의 휨성능 평가 -춤이 깊은 합성데크-)

  • Heo, Byung Wook;Kwak, Myong Keun;Bae, Kyu Woong;Jeong, Sang Min
    • Journal of Korean Society of Steel Construction
    • /
    • v.19 no.3
    • /
    • pp.247-258
    • /
    • 2007
  • This paper describes the results of an experimental study on the new type of encased composite beams that use deep deck plates, which could reduce the story height of buildings by controlling the bottom flange of steel beams. The profiled steel beam was thus developed. It was advantageous to the long span of the buildings. Seven full-scale specimens were constructed, and simply supported bending tests were conducted on the encased composite beams with different steel plate thicknesses, with and without shear studs, reinforcing bars, and web openings. The test results showed that the encased composite beams that were developed in this study had sufficient composite action without additional shear connectors due to their inherent shear-bond effects between the steel beams and concrete.

Analysis of the Load Carrying Behavior of Shear Connection at the Interface of Encased Composite Beams (매입형 합성보의 전단합성거동에 대한 비교분석)

  • Shin, Hyun Seop;Heo, Byung Wook;Bae, Kyu Woong;Kim, Keung Hwan
    • Journal of Korean Society of Steel Construction
    • /
    • v.20 no.1
    • /
    • pp.67-79
    • /
    • 2008
  • In this study, a bending test with three encased composite beams were carried out and analyzed using FEM in order to find how chemical adhesion, interface interlock, friction and composite action by shear studs contribute to stiffness, strength and composite action in the interface of encased compo site beams. The test and results of the FEM analysis showed that the difference in the ultimate moment capacity of the composite beams with and without studs is under 10%. The reason is that the effect of chemical adhesion, interface interlock, and friction in the interface on the composite action is so high that the encased beams have a moment capacity above some defined magnitude. Also, the increment of moment capacity up to plastic moment is not large and the increase of linearly proportioned.

Flexural Behavior of Encased Composite Beams with Partial Shear Interaction (매립형 불완전 합성보의 휨 거동 예측)

  • Heo, Byung Wook;Bae, Kyu Woong;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
    • /
    • v.16 no.6 s.73
    • /
    • pp.747-757
    • /
    • 2004
  • With steel and concrete composite beams, the incomplete interaction between the steel and the concrete slab leads to an appreciable increase in beam deflections. Moreover, encased composite beams using a deep deck plate or hollow-core PC slabs are critical to deflection due to their inherent geometry. In this paper, by using the calculation tools that were developed for a previous study on the deflection of encased composite beams considering the slip effects and load-slip curve, the shear bond stress and additional deflection induced due to interface slip of the encased composite beam are presented. It was found that the slip effects significantly contribute to the encased composite beam deflections and result in stiffness reduction of up to 30% compared to that of full shear interaction beams. The predicted results were compared with the measurement of 18 specimens tested in this study, and comparisons show a high degree of accuracy, within 6%.

Flexural Capacity of the Encased(Slim Floor) Composite Beams with Web Openings -Deep Deck Plate and Asymmetric Steel Beam to be Welded Cover Plate- (매립형 (슬림플로어) 유공 합성보의 휨성능 평가 -춤이 깊은 데크플레이트와 비대칭 H형강 철골보-)

  • Kwak, Myong Keun;Heo, Byung Wook;Bae, Kyu Woong
    • Journal of Korean Society of Steel Construction
    • /
    • v.16 no.5 s.72
    • /
    • pp.575-586
    • /
    • 2004
  • This paper presents an experimental study on the flexural capacity of an encased(slim-floor) composite beam, which is a wider plate under bottom flange of H-beam with web openings. Five simple full-scale bending tests were conducted on the encased(slim-floor) composite beams at varying steel beam heights (250mm and 300mm), positions of web openings, and loading conditions. The test results revealed that the web-open encased composite beam had sufficient composite action, without any additional shear connection devices, because of the inherent shear-bond effects between the steel beam and the concrete, and a stable structural performance without web-opening reinforcements.

Flexural performance of FRP-reinforced concrete encased steel composite beams

  • Kara, Ilker Fatih
    • Structural Engineering and Mechanics
    • /
    • v.59 no.4
    • /
    • pp.775-793
    • /
    • 2016
  • This paper presents a numerical method for estimating the curvature, deflection and moment capacity of FRP-reinforced concrete encased steel composite beams (FRP-RCS). A sectional analysis is first carried out to predict the moment-curvature relationship from which beam deflection and moment capacity are then calculated. Comparisons between theoretical and experimental results of tests conducted elsewhere show that the proposed numerical technique can accurately predict moment capacity and deflection of FRP-RCS composite beam. The numerical results also indicated that beam ductility and stiffness are improved when encased steel is added to FRP reinforced concrete beams. ACI, ISIS and Bischoff models for deflection prediction compared well at low load, however, significantly underestimated the experimental results for high load levels.

Experimental and Numerical Study of Fire Resistance of Composite Beams (무피복 합성보의 내화성능에 대한 실험 및 해석적 연구)

  • Ahn, Jae Kwon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
    • /
    • v.27 no.2
    • /
    • pp.143-153
    • /
    • 2015
  • In this paper, the standard fire resistance test under load and associated numerical study were carried out to evaluate the fire resistance of unprotected partially encased beams and slimfloor beams. The temperature evolution and the deflection increase of the composite beam specimens were investigated and the effects of the key behavioral parameters including the load ratio, the reinforcement, and the fire exposure were analyzed. The test results showed that the temperature rise of the partially encased beams and slimfloor beams is considerably slow compared to the conventional H-shape composite beams. Up to at least 90 minutes, the reinforcements in the partially encased composite beams maintained below the temperature at which the cold steel strength is sustained. Unprotected partially encased beams and slimfloor beams in the experimental program achieved the fire resistance more than 2 hours according to the limiting deflection criteria. This implies that unprotected partially encased beams and slimfloor beams can be very promising alternatives to enhancing the fire resistance of steel beams. This study also conducted the fully coupled thermal-stress analysis by using the commercial code ABAQUS to the thermal and structural behaviour of composite beams in fire. The numerical predictions provide acceptable correlations with the experimental results.

Shear behavior of the hollow-core partially-encased composite beams

  • Ye, Yanxia;Yao, Yifan;Zhang, Wei;Gao, Yue
    • Steel and Composite Structures
    • /
    • v.44 no.6
    • /
    • pp.883-898
    • /
    • 2022
  • A hollow-core partially-encased composite beam, named HPEC beam, is investigated in this paper. HPEC beam comprises I-beam, longitudinal reinforcement, stirrup, foam formwork, and cementitious grout. The foam formwork is located on both sides of the web, and cementitious grout is cast within the steel flange. To investigate the shear performance of HPEC beams, static loading tests of six HPEC beams and three control beams were conducted. The shear span ratio and the number of studs on the shear behavior of the HPECspecimens were studied. The failure mechanism was studied by analyzing the curves of shear force versus both deflection and strain. Based on the shear span ratio (𝜆), two typical shear failure modes were observed: shear compression failure when 1.6 ≤ 𝜆 ≤ 2; and diagonal compression failure when 𝜆 ≤ 1.15. Shear studs welded on the flange can significantly increase the shear capacity and integrity of HPEC beams. Flange welded shear studs are suggested. Based on the deformation coordination theory and superposition method, combined with the simplified modified compression field model and the Truss-arch model, Modified Deformation Coordination Truss-arch (M.D.C.T.) model was proposed. Compared with the shear capacity from YB9038-2006 and JGJ138-2016, the calculation results from M.D.C.T. model could provide reasonable predictions.

Flexural performance of composite beams with open-web π-shaped steel partially-encased by concrete

  • Liusheng Chu;Yunhui Chen;Jie Li;Yukun Yang;Danda Li;Xing Ma
    • Steel and Composite Structures
    • /
    • v.50 no.4
    • /
    • pp.419-428
    • /
    • 2024
  • Prefabricated partially-encased composite (PEC) structural component is widely used in construction industry due to its superior structural performance and easy assembly characteristic. However, the solid web in traditional PEC components tends to split concrete into two halves, thus potentially reduces structural integrity and requires double concrete pouring. To overcome the above disadvantages, a new PEC beam with open-web π-shaped steel is proposed in this paper. Four open-web PEC beams with varying sectional height, flange thickness and web void rate were constructed and tested under flexural loads. During experimental tests, all beams exhibited typical flexural failure modes with strong moment capacities and excellent ductility. Owing to the unique construction form of web opening, steel-concrete bonding properties were enhanced and very small relative steel-concrete slips were observed. Experimental results also showed that the flexural capacity of such PEC beams increased with the increase of the sectional height and flange thickness, while was not affected by the web void rate. At last, a flexural capacity formula of the open-web PEC beam was proposed based on the whole section plastic rule. The formula results agreed well with experimental results.

Ultimate behavior of composite beams with shallow I-sections

  • Gorkem, Selcuk Emre;Husem, Metin
    • Steel and Composite Structures
    • /
    • v.14 no.5
    • /
    • pp.493-509
    • /
    • 2013
  • Bending behavior of reinforced concrete slabs encased over shallow I-sections at different levels of compression heads were investigated in present study. 1500 mm long I-sections were used to create composite slabs. Compression heads of monolithic experimental members were encased at different levels into the concrete slabs. Shear connections were welded over some of the I-sections. The testing was carried out in accordance with the principles of four-point loading. Results revealed decreasing load bearing and deflection capacities of composite beams with increasing encasement depths into concrete. Mechanical properties of concrete and reinforcing steel were also examined. Resultant stresses calculated for composite beams at failure were found to be less than the yield strength of steel beams. Test results were discussed with regard to shear and slip effect.

Effect of local small diameter stud connectors on behavior of partially encased composite beams

  • Nguyen, Giang Bergerova;Machacek, Josef
    • Steel and Composite Structures
    • /
    • v.20 no.2
    • /
    • pp.251-266
    • /
    • 2016
  • The paper combines two distinct parts. First the behavior of welded headed studs with small diameters of 10 and 13 mm acting as shear connectors (which are not embraced in current standards) is studied. Based on standard push tests the load-slip relationships and strengths are evaluated. While the current standard (Eurocode 4 and AISC) formulas used for such studs give reasonable but too conservative strengths, less conservative and full load-slip rigidities are evaluated and recommended for a subsequent investigation or design. In the second part of the paper the partially encased beams under bending are analyzed. Following former experiments showing rather indistinct role of studs used for shear connection in such beams their role is studied. Numerical model employing ANSYS software is presented and validated using former experimental data. Subsequent parametric studies investigate the longitudinal shear between steel and concrete parts of the beams with respect to friction at the steel and concrete interface and contribution of studs with small diameters required predominantly for assembly stages (concreting). Substantial influence of the friction and effect of concrete confinement was observed with rather less noticeable contribution of the studs. Distribution of the longitudinal shear and its sharing between friction and studs is presented with concluding remarks.