Square Short Wood Columns Strengthened with FRP Sheets under Compressive Load

2012 ◽  
Vol 256-259 ◽  
pp. 1008-1011
Author(s):  
Yan Mei Zhu ◽  
Shu Cheng Yuan ◽  
Min Hou ◽  
Qing Yuan Wang
Keyword(s):  
Ultimate Strength ◽  
Failure Modes ◽  
Compressive Loading ◽  
Compressive Load ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Strength And Stiffness ◽  
Wood Columns

This paper presents the experimental results of the wood columns externally strengthened with fiber reinforced polymer (FRP) subjected to axial compressive loading. In total, 14 square short wood columns were made, which were reinforced by FRP in two reinforcing arrangements. The main parameters studied in the test were (1) the strengthening materials, i.e. carbon FRP (CFRP), basalt FRP (BFRP) and aramid FRP (AFRP); (2) the reinforcing arrangements, i.e. the full wrapping of FRP and the partial reinforcing arrangement; (3) the layers of FRP sheets applied, i.e. one, two and three. The ultimate strength, load-axial displacements curves, load-strain relationships, and the failure modes of all the columns were presented. The test results show that both types of the reinforcing arrangements could increase the ultimate strength and stiffness of the columns tested greatly. The columns strengthened with two layers of FRP sheets gave higher load carrying capacities when compared to the columns strengthened with one or three layers of FRP sheets. The result confirms that the more layers of FRP sheets, the higher of load carrying capacity; however, the adverse results were shown when three layers of FRP sheets applied. Finally, the result also showed that the full wrapping reinforcing arrangement is more effective than the partial one in enhancing the stiffness.

scholarly journals Experimental Investigation of the Fatigue Behavior of Basalt Fiber Reinforced Polymer Grid-Concrete Interface

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bo Wen ◽  
Chunfeng Wan ◽  
Lin Liu ◽  
Da Fang ◽  
Caiqian Yang
Keyword(s):  
Failure Modes ◽  
Fatigue Behavior ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Fiber Reinforced ◽  
Loading Level ◽  
Reinforced Polymer ◽  
Concrete Interface ◽  
Basalt Fiber Reinforced Polymer

Fatigue behavior is an important factor for mechanical analysis of concrete members reinforced by basalt fiber reinforced polymer (BFRP) grid and polymer cement mortar (PCM) and plays a critical role in ensuring the safety of reinforced concrete bridges and other structures. In this study, on the basis of the static loading test results of concrete specimens reinforced by BFRP grid and PCM, a series of fatigue tests with different loading levels were conducted on interfaces between BFRP grid and concrete to investigate the fatigue behavior of BFRP grid-concrete interfaces. The test results indicate that with high loading level, the fatigue failure mode of interface is interfacial peeling failure while it transforms to the fatigue fracture of the BFRP grid under low loading level. The fatigue life (S-N) curves of BFRP grid-concrete interface are obtained and fitted in stages according to different failure modes, and the critical point of the two failure modes is pointed out. The relative slip evolution of interface during fatigue is further revealed in different stages with two failure modes, and the law of interface strain is studied with the increase of fatigue times. The relation of effective bonding length of interface and fatigue times is also described.

scholarly journals Behavior of Hybrid CFRP Laminated Thin-Walled Beams: Experimental, Numerical, and Analytical Evaluations

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
A. M. Yosri ◽  
Gouda M. Ghanem ◽  
Mohamed A. E. Salama ◽  
Majed Alzara ◽  
Mohamed A. Farouk ◽  
...  
Keyword(s):  
Experimental Results ◽  
Fiber Reinforced Polymer ◽  
Core Material ◽  
Steel Beams ◽  
Specific Strength ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Hybrid Beams ◽  
Thin Walled ◽  
Strength And Stiffness

The aim of this paper is to assess the structural behavior of hybrid thin-walled beams which were fabricated using laminated carbon fiber reinforced polymer (CFRP). Seven hybrid (CFRP) I-beams were fabricated, instrumented, then have been tested under monotonic four-point loading in order to evaluate their behavior up to failure. In constructing the I-beam specimens which were evaluated in this study, plywood core was implemented on both the web and flanges. Several important parameters were conducted in this study considering changing both of the ply orientations and stacking sequences of laminated fibers, also changing the shear span-to-depth ratio (a/d) of the specimens. The experimental results showed that stacking sequence is the most significant parameter that influences both flexural strength and stiffness of the hybrid beams. Also, the experimental results promoted the effectiveness of the core material for enhancing the flexure (bending) stiffness of beams. Then, these results were compared with a previous simulated study which used the finite element modeling to model the beams. Also, in order to evaluate the efficiency of the CRFP beams, the results were compared to similar steel beams having the same dimensions of the CFRP beams. As compared to steel beams, the load carrying capacity of the laminated beams is being high compared with steel beams when taking into consideration their specific strength ratio.

scholarly journals Experimental Study on Slender CFRP-Confined Circular RC Columns under Axial Compression

2021 ◽  
Vol 11 (9) ◽  
pp. 3968
Author(s):  
Zhongjun Hu ◽  
Quanheng Li ◽  
Hongfeng Yan ◽  
Yuchuan Wen
Keyword(s):  
Axial Compression ◽  
Slenderness Ratio ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Test Results ◽  
Rc Columns ◽  
Compression Load ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Practical Engineering

The test results on the performance of carbon fiber-reinforced polymer (CFRP)-confined reinforced concrete (RC) columns under axial compression load are presented in this study. Twelve slender CFRP-confined circular RC columns with a diameter of 200 mm were divided into two groups. Six specimens with different slenderness ratios of 12, 20, 32, 40, 48, and 56 were contained in each group. The experimental results demonstrated the circumferential CFRP wrap was effective in enhancing the ultimate axial load of slender CFRP-confined circular RC columns compared with unwrapped RC columns. The experimental investigation also showed that the slenderness of the specimens had important influences on the axial compressive behavior, and the axial bearing capacity of slender CFRP-confined circular RC columns decreased as the slenderness ratio increased. In order to predict the load-carrying capacities of slender CFRP-confined circular RC columns, a formula was proposed and the prediction agreed with the experiments. The slenderness of slender CFRP-confined circular RC columns was recommended to be less than 26.5 in practical engineering.

Durability of Broken Concrete Specimens Strengthened with CFRP Sheets

2010 ◽  
Vol 123-125 ◽  
pp. 1119-1122
Author(s):  
Ming Ju Lee ◽  
Ming Gin Lee ◽  
Yi Shuo Huang ◽  
Yang Hsin Liang
Keyword(s):  
Flexural Strength ◽  
Flat Surface ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Externally Bonded

Carbon fiber-reinforced polymer (CFRP) composites are thin laminates that are externally bonded to broken concrete specimens using an epoxy system to increase their load-carrying capacity in this study. This paper reports the test results of broken concrete specimens strengthened with CFRP sheets and subjected to two aggressive environments including ultraviolet (UV) and freeze-thaw cycles. Test results revealed that three different CFRP layers are effective in retrofit on the broken compressive or flexural concrete specimens. The broken concrete specimens repaired with an epoxy and CFRP system could improve their compressive strength, flexural strength or ductility. Both aggressive environment tests didn’t cause obvious degradation to hardness index, compressive or flexural strength. The flexural specimens used half-U coating and anchorage systems were much higher strength than those only wrapped with CFRP sheets on the flat surface.

Influence of Freeze-Thaw Cycles on Bonded Interface Performance between CFRP and High Strength Concrete

2014 ◽  
Vol 638-640 ◽  
pp. 1516-1520 ◽  
Author(s):  
Lei Hong ◽  
Run Min Duo ◽  
Su Yan Wang ◽  
Lu Xi Li
Keyword(s):  
High Strength Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Bonded Joints ◽  
Test Results ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Reinforced Polymer

The bonded joints between carbon fiber reinforced polymer (CFRP) and high strength concrete subjected to different freeze-thaw cycles were studied and the results were analyzed. The test results indicate that with the increase of freeze-thaw cycles, effective bond length, ultimate bond load and ultimate global slip response will decrease. But it has little effects on initial stripping load. The failure modes change from adhesive debonding to shear failure of concrete.

Experimental Study on the Flexural Property of GFRP I-Beam

2012 ◽  
Vol 594-597 ◽  
pp. 757-760
Author(s):  
Jin Yang Zheng ◽  
Guang You Zhang ◽  
Yun He Chen ◽  
Shi Zhen Li
Keyword(s):  
Failure Modes ◽  
Local Buckling ◽  
Fiber Reinforced Polymer ◽  
Flexural Property ◽  
Test Results ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Bending Capacity ◽  
Integral Structure ◽  
Overall Bending

The glass fiber reinforced polymer (GFRP) I-beams were tested under the third-point static loading. The load, mid-span deflection and failure modes were recorded during the flexural test. The flexural property was analyzed. The test results indicate that local buckling result in failure of integral structure. The local stability of flange plate is one of the main factors that affect the overall bending capacity of GFRP I-beams. Local strengthening should be adopted in the flange-web joint.

Research on Static Load Tests of Damaged Bridge Strengthened with Pre-Stressed HFRP

2014 ◽  
Vol 1079-1080 ◽  
pp. 258-265
Author(s):  
Chen Ning Cai ◽  
Shan He ◽  
Li Na Liu ◽  
Shi Kun Ou
Keyword(s):  
Static Load ◽  
Flexural Rigidity ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Structural Members ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Load Tests

Thispaper presents an experimental study to strengthen an existing bridge usingpre-stressed carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer(GFRP) materials. The method using pre-stressed hybrid fiber reinforced polymer(HFRP) to strengthened structural members is an emerging pre-stressed strengtheningtechnology. In this study, experimental data selected from result of staticloading test conducted to hollow slabs with CFRP/GFRP has been compared with specimenswithout strengthening. Test results showed that the strengthening methoddeveloped in this study could effectively reduce the stress in hollow slab,improving the flexural rigidity and inhibiting the concrete from fracture.

scholarly journals Punching Shear Strength of Reinforced Concrete Flat Plates with GFRP Vertical Grids

2021 ◽  
Vol 11 (6) ◽  
pp. 2736
Author(s):  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Flat Plates ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Vertical Grids

In this study, the structural behavior of reinforced concrete flat plates shear reinforced with vertical grids made of a glass fiber reinforced polymer (GFRP) was experimentally evaluated. To examine the shear strength, experiments were performed on nine concrete slabs with different amounts and spacings of shear reinforcement. The test results indicated that the shear strength increased as the amount of shear reinforcement increased and as the spacing of the shear reinforcement decreased. The GFRP shear reinforcement changed the cracks and failure mode of the specimens from a brittle punching to flexure one. In addition, the experimental results are compared with a shear strength equation provided by different concrete design codes. This comparison demonstrates that all of the equations underestimate the shear strength of reinforced concrete flat plates shear reinforced with GFRP vertical grids. The shear strength of the equation by BS 8110 is able to calculate the punching shear strength reasonably for a concrete flat plate shear reinforced with GFRP vertical grids.

Study on the stiffness degradation in concrete continuous beam with externally prestressed CFRP tendons under fatigue loading

2021 ◽  
pp. 136943322199249
Author(s):  
Xing Li ◽  
Jiwen Zhang ◽  
Jun Cheng
Keyword(s):  
Fatigue Life ◽  
Fatigue Loading ◽  
Load Level ◽  
Fiber Reinforced Polymer ◽  
Stiffness Degradation ◽  
Test Results ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Practical Engineering ◽  
Good Agreement

This paper presents fatigue behaviors and the stiffness degradation law of concrete continuous beams with external prestressed carbon fiber-reinforced polymer (CFRP) tendons. Three specimens were tested under fatigue loading, and the influence of different load levels on the stiffness degradation and fatigue life were studied, and it was found that the stiffness degradation of three test specimens exhibited a three-stage change rule, namely rapid decrease, stable degradation, and sharp decline, but there are obvious differences in the rate and amplitude of stiffness degradation. The load level has a significant influence on the fatigue life of the test specimens. An analytical model with load level considered was proposed to calculate the residual stiffness and predict the stiffness degradation, which is in good agreement with the test results. The model of stiffness degradation presents a possible solution for practical engineering applications of concrete continuous beams with externally prestressed CFRP tendons subjected to different fatigue loadings.

Concrete Beams Reinforced with GFRP Plates

2017 ◽  
Vol 747 ◽  
pp. 220-225
Author(s):  
Alberto Pedro Busnelli ◽  
Ruben Edgardo López ◽  
Jorge Carlos Adue
Keyword(s):  
Glass Fiber ◽  
Carbon Fibers ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
The World ◽  
Critical Resistance

This is the presentation of the research carried out by the Faculty of Engineering at Universidad Nacional de Rosario on the use of pultruded Glass Fiber Reinforced Polymer (GFRP) plates to increase the flexural strength of reinforced concrete beams.Pultruded plates are the type of elements made of composite materials which are most widely used for this kind of strengthening. Although around the world the material used for these plates is carbon fibers, its high cost prevents its widespread use in our country.One of the aims of our research program is, precisely, to verify whether it is possible to substitute such plates for significantly cheaper glass fiber elements manufactured in Argentina. The test results have proved that this alternative is feasible.What's more, the greater thickness of the glass fiber plates allows the use of additional anchor bolts. These bolts provide the system with post-critical resistance and ductility-characteristics which are absolutely necessary, for example, in structures in seismic areas.

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