scholarly journals Experimental Study on Fatigue Performance of Negative Bending Moment of Steel-Concrete Continuous Composite Box Girder

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Pu Gao ◽  
Kuan Li ◽  
Yuanxun Zheng

The experimental work presents results on the fatigue performance of composite beams in the negative moment region and the changes of stiffness and deformation of composite beams under repeated loads; fatigue tests were carried out on two double-layer composite beams. The fatigue performance of composite beams with different reinforcement ratios under complete shear connection and the variation of deflection, strain of the reinforcement, strain of steel beam, and crack growth under fatigue load were obtained. The results showed that the fatigue resistance performance of concrete slab with low reinforcement ratio was much lower than that of concrete slab with high reinforcement ratio whereas, under the fatigue load, the stress of the welding nail in the negative moment region was small and the slip was almost negligible. The degradation of stiffness and the development of cracks were mainly due to the degradation of bond-slip between the concrete and reinforcement. The fatigue failure mode was the fracture of the upper reinforcement in negative moment region. The results obtained in this study are helpful in the design of composite beam.

2012 ◽  
Vol 166-169 ◽  
pp. 414-419
Author(s):  
Li Hua Chen ◽  
Fei Xiao ◽  
Qi Liang Jin

Based on the theoretical analysis and testing results, some key issues in design of outer-plated steel-concrete continuous composite beams are discussed. The influence of the form of steel beam upper flange on the behavior of composite beam is analyzed. The requirements about longitudinal reinforcement strength in the concrete flange of the negative moment region are given. It is suggested that the moment-shear interaction should be neglected when calculating the flexural capacity of outer-plated steel-concrete composite beams under negative bending moment. The behavior of longitudinal shear resistance at the interface between the concrete flange and web of composite beam is studied, and the related calculating formula is put forward based on the structural features of the composite beam.


2011 ◽  
Vol 243-249 ◽  
pp. 1117-1121
Author(s):  
Xu Hong Zhang ◽  
He Wu ◽  
Jian Ping Cao

A numerical study on slip effect of simply supported composite beams under negative bending moment is conducted by means of finite element program of ANSYS based on the feasibility verification of ANSYS. The research contents include: slip distribution rules; slip effect on deflection in service stage and ultimate bearing capacity; relationship between slip effect and shear connection、lognitudinal percentage of reinforcement and working behavior of composite beams with partial shear connection under negative bending moment .


Author(s):  
Bruno Briseghella ◽  
Junping He ◽  
Junqing Xue ◽  
Zordan Tobia

<p>Short and medium span continuous steel-concrete composite (SCC) girder bridges are becoming more and more popular. The problems caused by the negative bending moment in the continuous SCC girders cannot be ignored. In order to investigate the performances of the continuous joints between adjacent SCC girders, consist of steel endplates and headed shear stud connected to concrete cross-beam, the finite element model was built by using ABAQUS software, of which the accuracy was verified by experimental results. The parametric analyses were carried out to investigate the influences of the strength and reinforcement ratio of the concrete slabs in SCC girders, and the diameters of the horizontal headed shear studs on the performances of the joints. The ultimate moment capacity of the joint increases with the increase in the strength and reinforcement ratio of concrete slab and the diameters of the horizontal headed shear studs.</p>


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xinhua Liu ◽  
Jianren Zhang ◽  
Zihan Cheng ◽  
Meng Ye

The cracking of concrete in the negative moment region for a composite beam subjected to a negative bending moment reduces the beam’s strength and stiffness. To improve the cracking performance of composite beams, this paper presents an experimental investigation on applying ultrahigh-performance concrete (UHPC) instead of conventional concrete. Three steel-UHPC composite beams with different forms of joints were designed and tested through a unique rotation angle loading method using a spring displacement control testing setup. The crack distribution, rotation versus crack width, load versus spring displacement, and strains in the UHPC slab and steel girders were measured and studied. Nonlinear finite element analysis using ABAQUS based on the damaged plasticity model of concrete was carried out for comparison with the test results. The experimental and numerical results showed that the use of a UHPC slab can enhance the cracking performance of composite beams. Considering the convenience of construction, a reasonable joint form was suggested, and the appropriate UHPC longitudinal laying length in the negative moment region was proposed to be 0.1 L. Furthermore, a simplified formula for calculating the UHPC crack width was developed based on bond-slip theory.


Author(s):  
Xian Liang ◽  
Shujin Duan ◽  
Runming Niu ◽  
Fang Li

The difference between the steel and concrete composite-laminated action beam and the double steel and concrete composite action beam is in the connection of the top concrete slab and the steel top flange. The bending properties about the composite-laminated beam and the double composite beam in the negative flexural region are investigated in this paper. The relation of the cross section bending moment-curvature for the two types of composite beams under the action of negative bending moment are drawn by the whole process analysis method, and then the corresponding cracking moment, elastic ultimate bending moment and plastic ultimate bending moment are obtained. The analysis results have a good agreement with test data. Although the sectional bending stiffness and bending-carrying capacity of the composite-laminated beam and the double composite beam are comparable in the elastic state, the crack resistance of the composite-laminated beam is much better than that of the double composite beam.


2018 ◽  
Vol 11 (2) ◽  
pp. 331-356 ◽  
Author(s):  
A. D. PIASSI ◽  
J. V. DIAS ◽  
A. F. G. CALENZANI ◽  
F. C. C. MENANDRO

Abstract In the region of negative bending moments of continuous and semi-continuous steel and concrete composite beams, the inferior portion of the steel section is subjected to compression while the top flange is restricted by the slab, which may cause a global instability limit state know as lateral distortional buckling (LDB) characterized by a lateral displacement and rotation of the bottom flange with a distortion of the section’s web when it doesn’t have enough flexural rigidity. The ABNT NBR 8800:2008 provides an approximate procedure for the verification of this limit state, in which the resistant moment to LDB is obtained from the elastic critical moment in the negative moment region. One of the essential parameters for the evaluation of the critical moment is the composite beam’s rotational rigidity. This procedure is restricted only to to steel and concrete composite beams with sections that have plane webs. In this paper, an equation for the calculation of the rotational rigidity of cellular sections was developed in order to determine the LDB elastic critical moment. The formulation was verified by numerical analyses performed in ANSYS and its efficiency was confirmed. Finally, the procedure described in ABNT NBR 8800:2008 for the calculation of the critical LDB moment was expanded to composite beams with cellular sections in a numerical example with the appropriate modifications in geometric properties and rotational rigidity.


1975 ◽  
Vol 2 (1) ◽  
pp. 98-115
Author(s):  
A. E. Long ◽  
K. Van Dalen ◽  
P. Csagoly

The fatigue behavior of the negative moment region of continuous steel–concrete composite beams under Canadian temperature conditions was studied. Tests were conducted on three 26 ft 0 in. (7.92 m) long beams, continuous over a central support, and on 11 conventional push-out specimens. These were supplemented by a theoretical study of the internal forces in the beams using an iterative method of analysis.The close agreement between measured and theoretical strains and deflections indicated that good interaction was achieved throughout the length of the beams. The beams sustained 500 000 cycles of loading with no serious deterioration of composite action. The pattern of stud failures was consistent from beam to beam and reflected closely the calculated distribution of horizontal shear force at the steel–concrete interface. Stud shear connectors in the negative moment region where the slab had cracked in tension were found to be slightly less effective than studs in the positive bending moment regions.Neither the detailed study of individual connectors in the beams nor the results of the push-out tests show evidence of a reduction in the fatigue life of studs at −20 °F (−29 °C) relative to room temperature. The beams also exhibited no significant difference in their overall performance at these two temperatures.


2020 ◽  
Vol 10 (4) ◽  
pp. 1335 ◽  
Author(s):  
Shuwen Deng ◽  
Xudong Shao ◽  
Banfu Yan ◽  
Yan Wang ◽  
Huihui Li

Joints are always the focus of the precast structure for accelerated bridge construction. In this paper, a girder-to-girder joint suitable for steel-ultra-high-performance concrete (UHPC) lightweight composite bridge (LWCB) is proposed. Two flexural tests were conducted to verify the effectiveness of the proposed T-shaped girder-to-girder joint. The test results indicated that: (1) The T-shaped joint has a better cracking resistance than the traditional I-shaped joint; (2) The weak interfaces of the T-shaped joint are set in the areas with relatively lower negative bending moment, and thus the cracking risk could be decreased drastically; (3) The natural curing scheme for the joint is feasible, and the reinforcement has a very large inhibitory effect on the UHPC material shrinkage; The joint interface is the weak region of the LWCB, which requires careful consideration in future designs. Based on the experimental test results, the design and calculation methods for the deflection, crack width, and ultimate flexural capacity in the negative moment region of LWCB were presented.


2012 ◽  
Vol 166-169 ◽  
pp. 1023-1028 ◽  
Author(s):  
Li Hua Chen ◽  
Qi Liang Jin ◽  
Haiyu Si

Static load tests were conducted on two reversed-loading simply supported and two continuous outer-plated steel-concrete composite beams to study the formation and development of cracks in such beams under negative bending moment. The test results show that based on the plane section assumption, it is an effective and economical method to calculate the cracking moment of the composite beams assuming a rectangular stress block for concrete in tension zone. Considering the structural features of outer-plated steel-concrete composite beams, the formula for calculating crack width of concrete flange of outer-plated steel-concrete composite beams is discussed and presented, and the calculated values of crack width agree well with the experimental results.


2008 ◽  
Vol 400-402 ◽  
pp. 287-293
Author(s):  
Li Zhong Jiang ◽  
Lin Lin Sun ◽  
Xing Li

Based on the theoretical analysis of steel-concrete composite П-beam’s lateral buckling, the computing model and simplified computing model on the stability of composite П-beams are brought forward. According to above two models, composite beam’s lateral buckling is studied in negative moment regions using the energy method, and the formulas which are used to calculate critical bending moment in negative moment regions in the elastic stage are deduced. Compared with other stability theories and methods, this paper represents the design correction and suggestion about the stability of composite П-beam in negative bending regions. Moreover, the simplified calculation method, which is used to compute the lateral critical buckling moment of steel-concrete composite П-beam loaded by equal-end moment, not only simplifies the computing process, the computing results also have the equivalent accuracy with numerical computing methods.


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