Experimental Study of Cyclic Loading Behaviors of Impaired Reinforced Concrete Beams Strengthening with Prestressed CFRP Sheets

2012 ◽  
Vol 201-202 ◽  
pp. 483-486
Author(s):  
Li Yun Pan ◽  
Song Chen ◽  
Shun Bo Zhao ◽  
Chang Yong Li

The experimental study was carried out on the cyclic loading behaviors of impaired reinforced concrete beams strengthening with prestressed CFRP sheets. Eight beams in four groups with or without strengthening with prestressed CFRP sheets were tested, in which one or two layers of prestressed CFRP sheet were bonded on the bottom surface of the beams. Based on the analyses of test results, the flexural stiffness and ultimate resistance under cyclic load were effectively enhanced for the strengthened beams with the increasing layers of CFRP sheet, but the ductility of their mid-span deflection was reduced.

2011 ◽  
Vol 243-249 ◽  
pp. 929-933
Author(s):  
Na Ha ◽  
Lian Guang Wang ◽  
Shen Yuan Fu

In order to improve the bearing capacity of SRC which is related with deformation and stiffiness, SRC beams should be strengthened by CFRP. Based on the experiment of six pre-splitting steel reinforced concrete beams strengthened with (Prestressed) CFRP sheets, the deformation of beams are discussed. Load-deformation curves are obtained by the experiment. Considering the influence of intial bending moment on SRC beams, the calculated deformation formulas of SRC beams strengthened by (Prestressed) CFRP are deduced. The results showed that the load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The theoretical results which calculated by the formulas of deformation are well agreement with the experimental results.


2020 ◽  
Vol 1002 ◽  
pp. 604-614
Author(s):  
Hayder Hussein H. Kammona ◽  
Muhammad Abed Attiya ◽  
Qasim M. Shakir

This study simulates a procedure of rehabilitation of reinforced concrete beams with the aid of ANSYS 17 software. In this work, the BIRTH and DEATH procedure (in ANSYS) was adopted to model the post-repairing stage. This aspect has rarely been considered by previous studies that utilized a carbon fiber reinforced polymer (CFRP) sheet when retrofitting. To verify the suggested technique, six specimens were analyzed with two values of shear span-to-depth ratios (3 and 4) and three spaces of CFRP sheets (100mm, 150mm and 200mm). The effect of the repairing process on the structural performance of the retrofitted beam is also investigated.It is found that the suggested technique yielded a good agreement with the experimental results and the maximum differences in the failure loads between the numerical and experimental results were 10% and 4% for shear span-to-depth ratios of 3 and 4, respectively. It was also ascertained that upgrading reinforced concrete members within the early stages of loading showed a better enhancement in the loading capacity compared to upgrading reinforced concrete members close to the juncture of failure.


2012 ◽  
Vol 201-202 ◽  
pp. 304-307
Author(s):  
Li Yun Pan ◽  
Cheng Chen ◽  
Shun Bo Zhao ◽  
Chang Yong Li

Two large impaired reinforced concrete beams with pre-loading cracks were strengthened by the externally bonded steel frame composed with bottom steel plate and side hoop steel belts. The cyclic loading behaviors of these beams were tested to verify the effectiveness of this strengthening method specified in current Chinese design code. Based on the analyses of test results, the steel plate worked well with bonded concrete under normal service load, the hoop steel belts were necessary to prevent the peeling of bottom steel plate. The strengthened beams were effectively enhanced in flexural stiffness and ultimate resistance, and no new cracks appeared under the normal service load.


2021 ◽  
Vol 16 (59) ◽  
pp. 62-77
Author(s):  
Mahmoud Madqour ◽  
Khalid Fawzi ◽  
Hilal Hassan

In this research, the finite element method is used to develop a numerical model to analyse the effect of the external strengthening of reinforced concrete beams by using carbon Fiber Reinforced Polymer (CFRP) sheets. A finite element model has been developed to investigate the behavior of RC beams strengthened with CFRP sheets by testing nineteen externally simple R.C. beams, tested under a four-point load setup until failure. Various CFRP systems were used to strengthen the specimens.  The numerical results using the (ANSYS workbench v.19.1) were calibrated and validated with the experimental results.  The research results indicate a significant improvement in the structural behavior of the specimens strengthened using CFRP sheet systems. Then the validated model investigated the effect of the width of CFRP sheets, no of layers, and CFRP size on the behavior of strengthened R.C. beams. Results of this numerical investigation show the effectiveness of increase CFRP width to improve the flexural capacity of R.C. beams. An increase in the flexural capacity up to 100 % compared to the control beam.


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