Experimental study on low-strength concrete joint core strengthened with steel meshes for connecting PFCC column and RC beam

This paper presented a new joint core strengthened with multi-layer steel meshes for connecting the PVC-FRP Confined Concrete (PFCC) column and Reinforce Concrete (RC) beam. Seven specimens were tested under concentric compression and the effects of several parameters including the height, diameter of specimen and volume ratio of steel mesh on the compressive behaviors were investigated. Test results showed that all the reinforcement yielded successively and eventually the crushing of the concrete dominated the failures of specimens. The ultimate bearing capacity and ultimate equivalent axial strain decreased as the height of specimen increased, while they increased as the diameter of specimen or the volume ratio of steel mesh increased. The ultimate strains of all the reinforcement and concrete increased as the height of specimen increased while they decreased as the diameter of specimen or the volume ratio of steel mesh increased. Considering the influence of height of specimen, a modified formula for conveniently predicting the ultimate bearing capacity of the joint core strengthened with steel meshes was proposed based on the theory of confined concrete and superposition principle of multiple confinement. The predicted results were in good agreement with the experimental data. Additionally, an equivalent stress–strain relationship model of the joint core strengthened with steel meshes was suggested based on the experimental research. The predicted curves agreed well with the measured equivalent stress–strain curves. Moreover, a validated Finite Element (FE) model for the joint core strengthened with steel meshes was developed to conduct parametric studies, which broadened the available experimental results about the mechanical performances of the joint.

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Damage Constitutive Model and Mechanical Performance Deterioration of Concrete under Sulfate Environment

Mathematical Problems in Engineering ◽

10.1155/2020/3526590 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16

Author(s):

Peng Liu ◽

Ying Chen ◽

Zhiwu Yu ◽

Zhaohui Lu

Keyword(s):

Mechanical Properties ◽

Bearing Capacity ◽

Elasticity Modulus ◽

Mechanical Performance ◽

Sulfate Solution ◽

Concrete Surface ◽

Ultimate Bearing Capacity ◽

Stress Strain ◽

Before And After ◽

Relationship Model

The effects of erosion mode, erosion age, and concentration of sulfate solution on mechanical properties of concrete were investigated. The dimensionless relationship model of the stress-strain of concrete on the basis of randomness was proposed. The variation of the elasticity modulus and Poisson’s ratio of the concrete surface attacked by sulfate was studied, and a novel method of using a superficial parameter to characterize the performance change of the concrete surface was recommended. The results showed that the dimensionless relationship model of stress-strain of concrete could be used to represent the variations of mechanical properties of concrete. The differences of load-displacement of concrete before and after sulfate attack were reflected as the change of curve’s slope and ultimate bearing capacity, and the slope of a straight section of the lateral and longitudinal strain curves of concrete surface also varied. The increment rates of ultimate bearing capacity of concrete attacked by 1% and saturated sulfate solution were about 30% and 10%, respectively. However, the decreasing ratio of the ultimate bearing capacity of concrete attacked by saturated sulfate solution was approximately 25%. The damage factor of the elasticity modulus of the concrete surface of C20 and C40 was 0.185 and −0.19, respectively. The obtained results could provide a support for investigating the variations of stress-strain relationship and mechanical performance of concrete under a sulfate environment.

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The Research on Strengthening Technique for Aged RC Beam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.70 ◽

2011 ◽

Vol 255-260 ◽

pp. 70-73

Author(s):

Bin Xie ◽

Bin Jia ◽

Ru Heng Wang

Keyword(s):

Bond Strength ◽

Bearing Capacity ◽

Ultimate Bearing Capacity ◽

Rc Beam ◽

Strengthening Technique

The strengthening technique for the aged RC beam was introduced in this paper. A series of measures were utilized to increase the bond strength between CFRP and aged RC beam. The results of experiment indicate that ultimate bearing capacity of the strengthened RC beam increased almost 46%.

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A model for ultimate bearing capacity of PVC-CFRP confined concrete column with reinforced concrete beam joint under axial compression

Construction and Building Materials ◽

10.1016/j.conbuildmat.2019.04.131 ◽

2019 ◽

Vol 214 ◽

pp. 668-676 ◽

Cited By ~ 5

Author(s):

Feng Yu ◽

Dongang Li ◽

Ditao Niu ◽

Defeng Zhu ◽

Zhengyi Kong ◽

...

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Axial Compression ◽

Concrete Beam ◽

Reinforced Concrete Beam ◽

Ultimate Bearing Capacity ◽

Confined Concrete ◽

Concrete Column

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Experiment on Flexural Capacity of Damaged RC Beams Strengthened with Composite CFRP

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.932 ◽

2014 ◽

Vol 501-504 ◽

pp. 932-935

Author(s):

Tao Luo

Keyword(s):

Bearing Capacity ◽

Ultimate Bearing Capacity ◽

Experimental Results ◽

Rc Beam ◽

Rc Beams ◽

Reinforcement Effect ◽

Flexural Capacity ◽

Loading Test ◽

Research Results ◽

Cfrp Sheets

In order to study the flexural capacity of the seismic damaged RC beams after reinforcement, the bearing capacity and ductility are comprehensively evaluated, which is based on the results of three points of division loading test on 8 models which are divided into 4 groups. Experimental results show that compared with the direct pasting CFRP, the ultimate bearing capacity of RC beam strengthened by composite CFRP sheets is much higher, the average is 20.7%. Cracking load and ductility are also improved higher. The reinforcement effect of CFRP sheets is used very well. The research results provide advice and reference for the next seismic damaged RC beams in the reinforcement engineering.

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Experimental Study on the Bending Behavior of Steel-Wood Composite Beams

Advances in Civil Engineering ◽

10.1155/2021/1315849 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Shaowei Duan ◽

Wenzhao Zhou ◽

Xinglong Liu ◽

Jian Yuan ◽

Zhifeng Wang

Keyword(s):

Bearing Capacity ◽

Composite Beam ◽

Superposition Principle ◽

Composite Beams ◽

Ultimate Bearing Capacity ◽

Steel Beam ◽

Wood Composite ◽

Larch Wood ◽

H Beam ◽

Hot Rolled

This paper proposes a steel-wood composite beam with H-shaped steel beam webs glued to the wood. As a new type of composite beam, it combines the advantages of low energy consumption of wood, high permeability, and less pollution and the advantages of light weight and high strength of steel, high degree of assembly, short construction period, and less construction waste generated. Carrying out research is of great significance to improve the mechanical properties of steel-wood composite beams and promote the development of steel-wood composite structures. In this paper, three hot-rolled H-beam-larch composite beams and one pure steel beam were tested for bending capacity. The composite beams are divided into two different combinations of A and B types. The two sides of the web are connected with larch wood by structural glue to form a composite beam. The type B composite beam is a larch wood glued on both sides of the H-shaped steel web and penetrates the bolts at the same time. Through the three-point monotonic static grading loading of the composite beam, the deflection change, failure phenomenon, and form of the specimen during the experiment were observed. Under the circumstances, the ultimate bearing capacity of the test piece was changed to study the combined effect of larch and hot-rolled H-shaped steel. The results show that the overall performance of the H-shaped steel-larch composite beam is good. Bonding wooden boards on both sides of the steel beam web can improve the bearing capacity, and the form of the member is more reasonable and effective; increasing the cross-sectional size of the H-beam in the steel-wood composite beam can further improve the bearing capacity of the composite beam; adding bolt anchorage on the basis of the structural glue used in the composite beam can further improve the bearing capacity of the composite beam. The superposition principle is used to simplify the calculation of the ultimate bearing capacity of H-shaped steel-larch composite beams. Comparing the calculation results with the test results, the data are in good agreement, which can provide a design reference for the practical application of such composite beams.

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