scholarly journals Flexure Performance of Externally Bonded CFRP Plates-Strengthened Reinforced Concrete Members

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xin Yuan ◽  
Chaoyu Zhu ◽  
Wei Zheng ◽  
Jiangbei Hu ◽  
Baijian Tang

This paper investigates the flexural behavior of CFRP plate-strengthened concrete structures. Specimens of the CFRP plate-reinforced beam were designed and tested by the four-point flexural test. The load-deflection relationship, failure modes, and crack propagation were analyzed. The results showed that the postcracking stiffness and bearing capacity of the test beams can be improved by the additional anchoring measures for CFRP strengthening. The relationship between flexural moment and curvature was analyzed by introducing a MATLAB program. The calculation model between curvature, flexural moment, and stiffness was derived for the CFRP plate-strengthened structure. The recommended calculation model was applied in the analysis of deflection, and the theoretical values were compared with the test results.

1996 ◽  
Vol 118 (1) ◽  
pp. 53-61 ◽  
Author(s):  
E. M. Dexter ◽  
M. M. K. Lee ◽  
M. G. Kirkwood

Overlapped joints are generally regarded as having higher strengths than otherwise identical, simple nonoverlapping joints because of the more efficient load transfer between braces. However, not only that relatively little research has been carried out on such joints, the few test data from which current design guidance was derived has also been recently rejected. This paper reports the first phase of a parametric finite element study into the strength of overlapping K joints under axial loading. The numerical models were validated and calibrated against existing gap and overlapped K joint test results, and various factors which affect the relationship between the strength and the overlap amount, such as boundary restraints, hidden welds, loading hierarchy, and failure modes, were investigated. The results of the work presented lay the foundation for a future parametric study.


2012 ◽  
Vol 466-467 ◽  
pp. 225-228
Author(s):  
Kan Kang ◽  
Peng Zhang ◽  
Feng Tao Liu

Based on the the self-developed prestressed CFRP plate anchorage,the test specimens comprised 5 RC beams strengthened with the way the external prestressed CFRP plates,the research on the different prestressed tension and different span beam about the influence of the bending capacity , ultimate bearing capacity,cross section strain, CFRP strain and deflection of the test reinforced beams on the research. The test results showed that: the externally prestressed CFRP plate can obviously increase of the flexural performance of RC beams, and improve the utilization rate of the strength of the CFRP plate, through the external prestressed anchor of CFRP plate for a tension, reducing the RC beams crack, and improving the ductility of the RC beams.


2013 ◽  
Vol 658 ◽  
pp. 34-37 ◽  
Author(s):  
Seung Ju Han ◽  
Hyun Do Yun

This experimental study investigates the flexural behavior and toughness of sprayable strain-hardening cement composite (SHCC) developed to retrofit seismically reinforced concrete structures with non-ductile reinforcement details. Three SHCC mixtures with specified compressive strength of 50 MPa are mixed and tested. All SHCC mixes with different dosage and combination of admixtures such as superplasticizer and powder admixture were reinforced with 2.2 % polyvinyl alcohol (PVA) fibers at the volume fraction. This paper focuses on the flexural toughness based on the flexural test results for 100 x 100 x 400 mm prisms. The flexural toughness is evaluated in accordance with ASTM C 1018. The results indicated that less than 2.5 % dosage of hybrid superplasticizer and powder admixtures respectively provides excellent sprayability and flexural behavior of SHCC mixed in this study. A strong influence of hybrid superplasticizer and powder admixture on the flexural toughness of SHCC mixes was observed.


2015 ◽  
Vol 752-753 ◽  
pp. 610-616 ◽  
Author(s):  
Norhafizah Salleh ◽  
Abdul Rahman Mohd Sam ◽  
Jamaludin Mohd Yatim

There has been much research conducted on the current performance of Fiber Reinforced Polymer (FRP) as reinforcement. It was due to FRP easier to maintain than steel during construction because of less weight. Laboratory works on the flexural behavior of concrete beams that with GFRP and CFRP use as a plate strengthening for the beam size 2800 x 200 x 250 millimeter. study of the pattern of cracking and failure modes of the beam will be compared between the ten types of beams consisting of steel reinforced beams , beam-reinforced GFRP and GFRP reinforced beams strengthened with CFRP with different lengths. Comparing between the beam bending performance was examined through the ultimate load, cracking and failure modes.


2013 ◽  
Vol 639-640 ◽  
pp. 211-215 ◽  
Author(s):  
Xin Feng ◽  
Xian Yan Zhou

Retard-bonded prestressed concrete which has appeared in recent twenty years is a new and distinctive prestressed system. For the research on mechanical behavior and service property of retard-bonded prestressed concrete members, retard-bonded prestressed strands were made by manual work in this paper. Experimental research and theoretical analysis of three retard-bonded partially prestressed concrete T-beams were carried out under static loadings. The law of crack development and distribution both with the relationship between load and maximum crack width were studied in the paper. Test results were contrasted with experimental studies of two traditional partially prestressed concrete T-beams, and the characters and merits of retard-bonded partially prestressed concrete T-beams were obtained. It provides theoretical reference for the actual project application of the new retard-bonded prestressed concrete system.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Balaji Shanmugam ◽  
Manikandan Palanisamy ◽  
Paul O. Awoyera ◽  
Senthilnathan Chinnasamy ◽  
Mahalakshmi Subramaniam

This paper deals with a study conducted on flexural behavior of cold-formed steel built-up I-beams with hollow tubular flange sections. There were two types of test sections, namely, built-up sections that were assembled with either stiffened or unstiffened channels coupling back-to-back at the web and a hollow tubular rectangular flange at the top and bottom of the web to form built-up I-beam. The flexural behavior along with the strength and failure modes of the built-up sections was examined using the four-point loading system. Nonlinear finite element (FE) models were formulated and validated with the experimental test results. It was observed that the developed FE models had precisely predicted the behavior of built-up I-beams. Further, the verified FE models were used to conduct a detailed parametric study on cold-formed steel built-up beam sections with respect to thickness, depth, and yield stress of the material. The flexural strength of the beams was designed using the direct strength method as specified in American Iron and Steel Institute (AISI) for the design of cold-formed steel structural members and was compared with the experimental results and the failure loads predicted from FE models. Since the results were not conservative, a new customized design equation had been mooted and delineated in the study for determining the flexural strength of cold-formed steel built-up beams with hollow tubular flange sections.


2020 ◽  
Author(s):  
Faizan Siddique Awan ◽  
Raheela Rasheed ◽  
Ibrahim Qazi ◽  
Muhammad Umar Saeed

Abstract Two-dimensional glass fibers reinforced silica matrix composites (GFS) were fabricated by silica sol infiltration (SSI) method by varying the number of infiltration cycles. A uniform weight gain was observed after each infiltration up to 9 th infiltration suggesting the uniform loading of nano silica within GFS composites. The relationship between the infiltration cycle and the physical and flexural behavior of composites was measured by means of a density and 3-point flexural test along with supporting evidences via microstructural characterization. The results of mechanical testing indicated an increase in the flexural properties by up to 25%, after each infiltration cycle, due to increase in density. Finally, microstructural study revealed the presence of various toughening mechanisms during fracture, under flexural loading in the GFS composites.


2006 ◽  
Vol 306-308 ◽  
pp. 1361-1366 ◽  
Author(s):  
Sang Kyoon Jeong ◽  
Seung Sik Lee ◽  
C.H. Kim ◽  
Dong Min Ok ◽  
Soon Jong Yoon

Nowadays, the investigations relating to the FRP re-bars have been increased due to their superior physical and mechanical properties such as environmental resistance, electro-magnetic transparency, and high specific strength and stiffness. In this paper, we present the results of an experimental investigation pertaining to the flexural behavior of concrete beams reinforced with GFRP re-bar bundles for tension and CFRP grids for shear. A total of eight specimens, two pairs of four different shear reinforcement spaces, is loaded to failure under the 4-point bending test set-up. In addition to the experimental investigation, theoretical evaluation is also conducted according to the ACI Committee 440 for all beam specimens. Both experimental and theoretical results such as failure modes and load-deflection relations are compared and good agreements are observed.


2012 ◽  
Vol 517 ◽  
pp. 881-886 ◽  
Author(s):  
Zi Xiong Guo ◽  
Yong Ye ◽  
Bao Cheng Liu ◽  
Yang Liu

A technique for increasing the flexural behavior of stone beams using near-surface mounted (NSM) carbon fiber reinforced polymer (CFRP) rods is proposed. Four granite beams were tested under monotonic loading to investigate the effectiveness of this technique. One conventional stone beam was kept unreinforced as the control specimen and three beams were reinforced with NSM CFRP rods. The main test parameters included rod diameters and reinforcement ratios. Three types of failure modes were observed during testing, namely, abrupt fracture for conventional stone beams, flexure failure for moderately-reinforced beams and flexure-shear failure for over-reinforced beams, respectively. Test results showed that reinforcing with NSM CFRP could significantly enhance the flexural behavior of stone beams. For specimens with a reinforcement ratio of 0.14%, an average increase up to 91.0% in the ultimate load with respect to that of the control beam was obtained and the deformation capacity was dramatically increased. For specimens with a reinforcement ratio of 0.28%, though flexural behavior was greatly enhanced, an unfavorable shear failure was observed.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3326
Author(s):  
Zhijin Zhang ◽  
Yi Zhang ◽  
Xingliang Jiang ◽  
Jianlin Hu ◽  
Qin Hu

Due to the complex structure of insulators, it is difficult to use parameters such as icicle length or ice thickness of an insulator to directly characterize the degree of icing of an insulator. Rotating conductors are widely used in monitoring icing degree on insulators, but the relationship between ice degree on the insulator and the rotating conductor has not been verified. In this paper, the water droplets collision coefficient α1 was put forward to characterize icing degree, and a new numerical calculation model where α1 on different regions of an insulator is calculated was proposed. Combining the freezing fraction α3 of the insulator and rotating conductor, the equivalent relationship of ice weight between insulator and rotating conductor can be established, which was afterwards verified through the icing tests. The test results indicate that ice weight on an insulator increases linearly with the increase of ice weight on the rotating conductor, and the model proposed in this paper can reflect actual results more accurately than previous models. In such cases, the method of using ice weight on a rotating conductor to predict that on an insulator based on the model proposed in this paper could be widely adopted.


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