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 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.

Flexural Behavior of Steel Fiber Reinforced Self-Stressing Concrete in Continuous Systems

2011 ◽  
Vol 675-677 ◽  
pp. 705-708
Author(s):  
Bo Xin Wang ◽  
Huan An He
Keyword(s):  
Steel Fiber ◽  
Flexural Behavior ◽  
Relative Deformation ◽  
Fiber Reinforced ◽  
Conventional Concrete ◽  
Model Experiments ◽  
Flexural Performance ◽  
Continuous Beams ◽  
Steel Bars ◽  
Joint Material

Steel Fiber Reinforced Self-stressing Concrete (SFRSSC for short) is a new type of high performance cementitious composite with self-expansive performance and high tensile resistance. It can be used as a joint material in the new bridge construction or the old bridge rehabilitation. Because when SFRSSC is restrained by steel bars and other terminal conditions, it can create chemical pre-stressing force to enhance the cracking moments of the continuous beams. For purpose of utilizing the properties of SFRSSC, the primary goal of this research is to apply SFRSSC as a joint material to build continuous bridges. Firstly, the model experiments of 8 continuous Tbeams with SFRSSC layers are carried out. Secondly, based on the model experiments, flexural performance of the beams reinforced by SFRSSC layers is investigated. Owing to enhancement of steel fibers and self-stress induced by steel bars, the layers greatly improve the first-crack strength and stiffness of the continuous T-beams. The test results obviously indicate that the composite SFRSSC-RC continuous T-beams enhance the crack moment 51.4%～121% more than conventional concrete continuous beams. Furthermore, SFRSSC can help cancel out the relative deformation and stress due to new concrete shrinkage between new and existing concrete during the process transforming simply supported beams into continuous beams. It is concluded that flexural performance of continuous T-beams strengthened by SFRSSC is more greatly improved than that strengthened by conventional concrete.

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.

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.

The Lateral Buckling of Steel-Concrete Composite П-Beam

2008 ◽  
Vol 400-402 ◽  
pp. 287-293
Author(s):  
Li Zhong Jiang ◽  
Lin Lin Sun ◽  
Xing Li
Keyword(s):  
Bending Moment ◽  
Computing Methods ◽  
Lateral Buckling ◽  
Computing Model ◽  
Negative Moment ◽  
Numerical Computing ◽  
Negative Bending ◽  
The Stability ◽  
Simplified Calculation ◽  
Elastic Stage

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.

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.

The Best Position to Determine the Hinge in the Cantilever Bridge

2014 ◽  
Vol 578-579 ◽  
pp. 814-817
Author(s):  
Chun Lei Liu ◽  
Su Juan Dai
Keyword(s):  
Optimum Design ◽  
Bending Moment ◽  
Internal Force ◽  
Cantilever Beams ◽  
Structure Form ◽  
Absolute Value ◽  
Large Span ◽  
Common Structure ◽  
Negative Bending ◽  
Beam Bridge

The simple-supported beam bridge is a common structure form widely used in small and medium span bridges. When the span is longer, the maximum bending moment is accordingly bigger. The maximum positive and negative bending moment numerical of beam decreases obviously because of cantilever bridge with cantilever beams to reduce the amount of materials. This article analyzes the current commonly used cantilever bridge with large span. The two-span cantilever bridge is analyzed under various loads about the internal force according to the condition of the absolute value of the maximum positive and negative bending moment being equal. It carries on the contrast and analysis about simple-supported beam bridges and obtains the best location of the hinge in the cantilever bridge. Moreover, it provides some reference for the optimum design of similar bridges and projects.

Preparation and Performances of Self-Compacting Concrete Used in the Joint Section between Steel and Concrete Box Girders of Edong Yangtze River Highway Bridge

2010 ◽  
Vol 168-170 ◽  
pp. 334-340
Author(s):  
Bei Xing Li ◽  
Ai Jun Guan ◽  
Ming Kai Zhou
Keyword(s):  
Crack Resistance ◽  
Yangtze River ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Scale Model ◽  
Fiber Reinforced ◽  
Freezing And Thawing ◽  
Self Compacting Concrete ◽  
Box Girders ◽  
Joint Section

The joint section between steel and concrete box girders is the key localization of the super-long span hybrid girder cable-stayed bridge in the Edong Yangtze River, a high strength self-compacting concrete (SCC) was required to use in the joint section. This paper systematically investigated the performances of three types of C55 grade self-compacting concretes (SCCs), such as plain SCC, micro-expansion and polypropylene fiber reinforced SCC and steel fiber reinforced SCC. The results indicated that the steel fiber reinforced SCC had the best workability and mechanical properties. The flexural toughness of the steel fiber reinforced SCC was much better than that of the other two types of concretes. The addition of steel fiber, or polypropylene fiber and expansive agent improved the crack resistance of SCC, and the micro-expansion and polypropylene fiber SCC reinforced had better crack resistance than steel fiber reinforced SCC. The three types of SCCs have very high chloride penetration resistance and advanced freezing and thawing resistance. Moreover, the test achievement of concrete casting technology for the full-scale model of steel girder chambers in the joint section is introduced. The steel fiber reinforced SCC was preferred to be used in the steel-concrete joint section.

Study on Losses of Self-Stress Created by Steel Fiber Reinforced Self-Stressing Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 300-303 ◽  
Author(s):  
Bo Xin Wang ◽  
He Nan Jin ◽  
Teng Man
Keyword(s):  
Steel Fiber ◽  
Theoretical Models ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Bars ◽  
The Matrix ◽  
The Stability

Based on the 9-year-experiment of self-stressing concrete (SSC for short), the stability of self-stress caused by steel bars and steel fibers is investigated. The results show that the losses of self-stress are only from 0.6 MPa to 1.2 MPa during 2.5 years. Meanwhile the matrix of steel fiber reinforced self-stressing concrete (SFRSSC for short) has the characteristic of secondary expansion. Finally, according to the existing theoretical models, formulas of the losses of self-stress created by SFRSSC are obtained.

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