scholarly journals Experimental and Numerical Studies on the Negative Flexural Behavior of Steel-UHPC Composite Beams

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xinhua Liu ◽  
Jianren Zhang ◽  
Zihan Cheng ◽  
Meng Ye
Keyword(s):  
Crack Width ◽  
Bending Moment ◽  
Composite Beams ◽  
Flexural Behavior ◽  
Element Analysis ◽  
Conventional Concrete ◽  
Bond Slip ◽  
Cracking Performance ◽  
Negative Moment ◽  
Negative Bending

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.

Study on the Crack in Concrete Flange of Outer-Plated Steel-Concrete Continuous Composite Beams

2012 ◽  
Vol 166-169 ◽  
pp. 1023-1028 ◽  
Author(s):  
Li Hua Chen ◽  
Qi Liang Jin ◽  
Haiyu Si
Keyword(s):  
Crack Width ◽  
Static Load ◽  
Bending Moment ◽  
Structural Features ◽  
Composite Beams ◽  
Test Results ◽  
Load Tests ◽  
Reversed Loading ◽  
Negative Bending ◽  
Stress Block

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.

Research on Key Issues in Design of Outer-Plated Steel-Concrete Continuous Composite Beams

2012 ◽  
Vol 166-169 ◽  
pp. 414-419
Author(s):  
Li Hua Chen ◽  
Fei Xiao ◽  
Qi Liang Jin
Keyword(s):  
Composite Beam ◽  
Bending Moment ◽  
Longitudinal Shear ◽  
Structural Features ◽  
Composite Beams ◽  
Steel Beam ◽  
Negative Moment ◽  
Key Issues ◽  
Negative Bending ◽  
The Moment

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.

Study on Crack Resistance of Steel Fiber Reinforced Self-Stressing Concrete in Old Bridge Reinforcement

2008 ◽  
Vol 400-402 ◽  
pp. 543-548
Author(s):  
Bo Xin Wang ◽  
Cheng Kui Huang
Keyword(s):  
Crack Resistance ◽  
Steel Fiber ◽  
Bending Moment ◽  
Theoretical Models ◽  
Internal Force ◽  
Fiber Reinforced ◽  
Conventional Concrete ◽  
Continuous Beams ◽  
Negative Moment ◽  
Negative Bending

Steel Fiber Reinforced Self-stressing Concrete (SFRSSC) is a new type of fiber reinforced composite material. It has various applications in civil engineering for its well known superior properties such as self-expansive performance and high tensile resistance. However, it is not widely accepted as an effective reinforcement in the rehabilitation of the old bridges at present. The primary goal of this research is to apply SFRSSC to improve the crack resistance in the negative bending moment areas of the old bridges. Firstly, a computer analysis on the internal force of the continuous T-beams with 5 spans is given in this paper. The results show that the expansive action of SFRSSC can effectively decrease the internal force in the negative bending moment area. Meanwhile, based on the experiments of 5 composite concrete inverted T-beams, the crack resistance of the beams reinforced with SFRSSC layers is investigated. The test results obviously indicated that the composite layers enhanced the cracking moments 44.9% more than conventional concrete layers, though its height is only 13.9% of the cross section height. It is concluded that the continuous beams strengthened by SFRSSC has greatly improved the crack resistance in negative bending moment areas compared with the continuous beams strengthened by conventional concrete. According to the existing theoretical models, a procedure how to determine the self-stress is supplied and a formula which evaluating the crack resistance of composite T-beams in negative moment area is deduced in order to supply references to the old bridge rehabilitation design.

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
Keyword(s):  
Concrete Slab ◽  
Bending Moment ◽  
Composite Beams ◽  
Fatigue Tests ◽  
Reinforcement Ratio ◽  
Fatigue Performance ◽  
Fatigue Load ◽  
Shear Connection ◽  
Negative Moment ◽  
Negative Bending

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.

scholarly journals Lateral distortional buckling of cellular composite-beams

2018 ◽  
Vol 11 (2) ◽  
pp. 331-356 ◽  
Author(s):  
A. D. PIASSI ◽  
J. V. DIAS ◽  
A. F. G. CALENZANI ◽  
F. C. C. MENANDRO
Keyword(s):  
Flexural Rigidity ◽  
Lateral Displacement ◽  
Limit State ◽  
Composite Beams ◽  
Bottom Flange ◽  
Distortional Buckling ◽  
Critical Moment ◽  
Negative Moment ◽  
Resistant Moment ◽  
Negative Bending

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.

Finite Element Analysis on Incremental Launching Construction for Steel Box Girder

2013 ◽  
Vol 671-674 ◽  
pp. 974-979
Author(s):  
Jie Dai ◽  
Jin Di ◽  
Feng Jiang Qin ◽  
Min Zhao ◽  
Wen Ru Lu
Keyword(s):  
Finite Element ◽  
Bending Moment ◽  
Internal Force ◽  
Element Analysis ◽  
Box Girder ◽  
Finite Element Software ◽  
Cable Stayed Bridge ◽  
Steel Box Girder ◽  
Maximum Value ◽  
Negative Bending

For steel box girder of cable-stayed bridge, which using incremental launching method, during the launching process, structural system and boundary conditions were changing, structure mechanical behaviors were complex. It was necessary to conduct a comprehensive analysis on internal force and deformation of the whole structure during the launching process. Took a cable-stayed bridge with single tower, double cable planes and steel box girder in China as an example; finite element software MIDAS Civil 2010 was used to establish a model for steel box girder, simulation analysis of the entire incremental launching process was carried out. Variation rules and envelopes of the internal force, stress, deformation and support reaction were obtained. The result showed that: the maximum value of positive bending moment after launching complete was 60% of the maximum value of positive bending moment during the launching process. The maximum value of negative bending moment after launching complete was 78% of the maximum value of negative bending moment during the launching process.

Short-term behaviour of reinforced and steel fibre–reinforced concrete composite slabs with steel decking under negative bending moment

2017 ◽  
Vol 21 (9) ◽  
pp. 1288-1301 ◽  
Author(s):  
Alireza Gholamhoseini ◽  
Amir Khanlou ◽  
Gregory MacRae ◽  
Stephen Hicks ◽  
Allan Scott ◽  
...  
Keyword(s):  
Crack Width ◽  
Ultimate Load ◽  
Steel Fibre ◽  
Bending Moment ◽  
Fibre Reinforced Concrete ◽  
Short Term ◽  
Crack Control ◽  
Steel Fibre Reinforced Concrete ◽  
Composite Slabs ◽  
Negative Bending

An experimental study was conducted on reinforced and steel fibre–reinforced concrete composite slabs with steel decking under negative bending moment to quantify the ultimate behaviour, loading capacity and crack width under short-term loading. Eight full-scale slab specimens were cast with different types and amounts of reinforcement in the concrete (e.g. mesh, steel fibre or normal reinforcing bars) but with the same type of steel decking. Each slab was simply supported and tested in four-point bending under increasing load until failure. The deflections at mid-span and under the applied point loads were monitored together with the end interface slip. The crack widths were obtained for each slab for different levels of applied load. It was found that the end slip was quite negligible and complete interaction on the steel decking–concrete slab interface existed at service loads and ultimate limit states. Compared to the slab with 20 kg/m3 steel fibre, the application of steel fibre in excess of 60 kg/m3 increased the rotational capacity and ultimate load by 60% and 80%, respectively. Moreover, the higher dosage of steel fibres resulted in improved crack control, as for the same level of applied load, the crack width was often reduced by 75%. However, the slabs with conventional high-strength ductile reinforcements had the greatest ultimate load and rotational capacity and exhibited the best degree of crack control with finer and more distributed cracks.

The Fatigue Behavior of Negative Moment Regions of Continuous Composite Beams at Low Temperatures

1975 ◽  
Vol 2 (1) ◽  
pp. 98-115
Author(s):  
A. E. Long ◽  
K. Van Dalen ◽  
P. Csagoly
Keyword(s):  
Fatigue Behavior ◽  
Bending Moment ◽  
Composite Beams ◽  
Horizontal Shear ◽  
Shear Connectors ◽  
Significant Difference ◽  
Show Evidence ◽  
Negative Moment ◽  
Central Support ◽  
Push Out

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.

scholarly journals On Flexural Performance of Girder-To-Girder Wet Joint for Lightweight Steel-UHPC Composite Bridge

2020 ◽  
Vol 10 (4) ◽  
pp. 1335 ◽  
Author(s):  
Shuwen Deng ◽  
Xudong Shao ◽  
Banfu Yan ◽  
Yan Wang ◽  
Huihui Li
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Bending Moment ◽  
Inhibitory Effect ◽  
Careful Consideration ◽  
Joint Interface ◽  
Test Results ◽  
Negative Moment ◽  
Composite Bridge ◽  
Negative Bending

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.

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