Simulating the Stiffness of RC Beams Strengthened by CFRP with Secondary Load by ANSYS

2013 ◽  
Vol 444-445 ◽  
pp. 1062-1066
Author(s):  
Li Ping Sun ◽  
Zheng Liu ◽  
Chen Xing Yang ◽  
Ze Fu Zhang
Keyword(s):  
Stress Distribution ◽  
Rc Beams ◽  
Load History ◽  
Flexural Members ◽  
Flexural Performance ◽  
Secondary Load ◽  
Initial Load

The purpose of the paper is to simulate stress distribution of flexural members which is reinforced with CFRP with secondary load using ANSYS, so the flexural performance the beams containing with same layer of CFRP which is affected by different torque can be studied. As a result, the comparison of the stiffness and deflection of beams influenced by different load history (with initial load or not) and different layers of CFRP in this paper will provide guidance for project.

Experimental study on flexural strengthening of reinforced concrete beams with U-shaped steel under secondary load

2021 ◽  
pp. 136943322110369
Author(s):  
Qingli Lin ◽  
Yiyan Lu ◽  
Wenshui Tang ◽  
Dongshan Lei
Keyword(s):  
Reinforced Concrete ◽  
Reference Beam ◽  
Reinforced Concrete Beams ◽  
Bottom Plate ◽  
Strengthening Effect ◽  
Rc Beams ◽  
Flexural Strengthening ◽  
Flexural Performance ◽  
Initial Loading ◽  
Secondary Load

This study proposes a new method to strengthen reinforced concrete (RC) beams with U-shaped steel, which can achieve rapid construction and great improvement in the flexural performance of RC beams. To investigate the influence of secondary load defined as newly applied loads after strengthening on the strengthening effect, a total of nine specimens were tested under four-point bending, including a reference beam, a strengthened beam under initial load, and seven strengthened beams under secondary load. The initial loading degree, the thickness of the bottom plate, and the height of the steel box were the main variables considered in this study. Testing results showed that compared with the reference beam, the flexural performance of strengthened beams was significantly enhanced, indicating the good joint performance of the U-shaped steel and the RC beams. Among the three main variables, the initial loading degree was found to have a minimal effect on the flexural performance while the thickness of the bottom plate and the height of the steel box had considerable influence, with the latter having a more pronounced effect. Testing results also showed that most of the strengthened beams experienced flexural failures, which were reflected by steel web peeling and buckling, and concrete crushing. Moreover, a formula was derived for calculating the flexural capacity of strengthened beams under secondary load. The results from the derived formula were found to be in good agreement with those from experiments.

scholarly journals Study on the flexural performance of RC beams anchored with CFRP plates under secondary load

2021 ◽  
Vol 233 ◽  
pp. 03024
Author(s):  
Xiangrui Feng ◽  
Xian Cui ◽  
Haikun Luo
Keyword(s):  
Bearing Capacity ◽  
Bending Strength ◽  
Concrete Beams ◽  
Ultimate Bearing Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Flexural Performance ◽  
Cfrp Plate ◽  
Secondary Load ◽  
Structural Indicators

In order to explore the influence of length and width of CFRP as well as anchor spacing on the reinforcement effectiveness of CFRP plates on reinforcement concrete beams (RC beams) under secondary load, 7 anchored damaged FRP reinforced concrete beams are used as test beams, 1 unanchored beam is used as a control beam, and structural indicators such as ultimate load and bending strength are analyzed in the result. The conclusion is that composite CFRP plate can effectively prevent the early peeling and failure of carbon plates and improve the ultimate bearing capacity of the beam. When the width of the CFRP plate decreases, the thickness increases and the steel plate anchor spacing increases appropriately, the ultimate bearing capacity and ductility of the beam are significantly improved.

scholarly journals Flexural Performance of RC Beams Strengthened with Externally-Side Bonded Reinforcement (E-SBR) Technique Using CFRP Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2809
Author(s):  
Md. Akter Hosen ◽  
Fadi Althoey ◽  
Mohd Zamin Jumaat ◽  
U. Johnson Alengaram ◽  
N. H. Ramli Sulong
Keyword(s):  
Absorption Capacity ◽  
Experimental Program ◽  
Rc Beams ◽  
Rc Structures ◽  
Functional Changes ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Flexural Performance ◽  
Design Loads ◽  
Predicted Values

Reinforced concrete (RC) structures necessitate strengthening for various reasons. These include ageing, deterioration of materials due to environmental effects, trivial initial design and construction, deficiency of maintenance, the advancement of design loads, and functional changes. RC structures strengthening with the carbon fiber reinforced polymer (CFRP) has been used extensively during the last few decades due to their advantages over steel reinforcement. This paper introduces an experimental approach for flexural strengthening of RC beams with Externally-Side Bonded Reinforcement (E-SBR) using CFRP fabrics. The experimental program comprises eight full-scale RC beams tested under a four-point flexural test up to failure. The parameters investigated include the main tensile steel reinforcing ratio and the width of CFRP fabrics. The experimental outcomes show that an increase in the tensile reinforcement ratio and width of the CFRP laminates enhanced the first cracking and ultimate load-bearing capacities of the strengthened beams up to 141 and 174%, respectively, compared to the control beam. The strengthened RC beams exhibited superior energy absorption capacity, stiffness, and ductile response. The comparison of the experimental and predicted values shows that these two are in good agreement.

Susceptibility of strain-hardening cementitious composite to curing conditions as a retrofitting material for RC beams

2021 ◽  
Vol 16 ◽  
pp. 155892502110203
Author(s):  
Mohammad Iqbal Khan ◽  
Galal Fares ◽  
Yassir Mohammed Abbas ◽  
Wasim Abbass ◽  
Sardar Umer Sial
Keyword(s):  
Strain Hardening ◽  
Environmental Conditions ◽  
Carrying Capacity ◽  
Flexural Behavior ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Curing Conditions ◽  
Flexural Members ◽  
Load Carrying ◽  
Curing Regime

Strain-hardening cement-based composites (SHCC) have recently been developed as repair materials for the improvement of crack control and strength of flexural members. This work focuses on strengthening and flexural enhancement using SHCC layer in tensile regions of flexural members under three different curing conditions. The curing conditions simulate the effect of different environmental conditions prevailing in the central and coastal regions of the Arabian Peninsula on the properties of SHCC as a retrofitting material. In this investigation, beams with SHCC layer were compared to control beams. The beams with SHCC layer of 50-mm thickness were cast. The results revealed that the flexural behavior and the load-carrying capacity of the normal concrete beam specimens under hot and dry environmental conditions were significantly reduced, lowering the ductility of the section. However, compressive strength is comparatively unaffected. Similarly, the hot curing conditions have also led to a notable reduction in the loading capacity of the beam with SHCC layer with a slight effect on its stiffness. On the other hand, steam-curing conditions have shown improvement in load-carrying capacity and a reduction in section ductility of the beam with SHCC layer. It was found that the structural unit retrofitted with SHCC layer was a curing-regime dependent as the tensile and strain-hardening properties of SHCC are highly sensitive to the alteration in the cement hydration process. A normal curing regime was found effective and satisfying the practical, cost, and performance requirements. Accordingly, a normal curing regime could be implemented to retrofit reinforced concrete (RC) beams with SHCC layers as recommended in the study.

Enhancement of flexural performance of RC beams with steel wire rope by external strengthening technique

2021 ◽  
pp. 1-11
Author(s):  
Yanuar Haryanto ◽  
Ay Lie Han ◽  
Hsuan-Teh Hu ◽  
Fu-Pei Hsiao ◽  
Banu Ardi Hidayat ◽  
...  
Keyword(s):  
Steel Wire ◽  
Wire Rope ◽  
Rc Beams ◽  
Flexural Performance ◽  
External Strengthening ◽  
Strengthening Technique

Reliability-Based Balanced Condition for Strengthened RC Beams

2013 ◽  
Vol 756-759 ◽  
pp. 25-28 ◽  
Author(s):  
Chun Xia Li ◽  
Zhi Sheng Ding ◽  
Shi Lin Yan ◽  
Jun Ming Chen
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Stress Distribution ◽  
Tensile Strain ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Experimental Result ◽  
Rc Beams ◽  
Yield Strain ◽  
Reliability Indicator

Based on the experimental result of the flexure capability of reinforced concrete beams strengthened by carbon fiber sheets, the stress distribution changes only after steel yielding and carbon fiber sheets function better. However serious the extent of the damage is before strengthened, the tensile strain of main steel reaches about 1.6 times of the yield strain for the secondary grade of steel as failure happens. To satisfy the object reliability indicator, reliability is analyzed using the ratio of the steel strain at the balanced failure to the yield strain as variable to obtain its optimum value, which is coincide with the experimental result, and makes better consistency between calculated reliability indicator and object reliability indicator.

scholarly journals Fracture toughness of RC beams on the shear, strengthening by FRCM system

2018 ◽  
Vol 183 ◽  
pp. 02009 ◽  
Author(s):  
Zinoviy Blikharskyy ◽  
Pavlo Vegera ◽  
Rostyslav Vashkevych ◽  
Taras Shnal
Keyword(s):  
Fracture Toughness ◽  
Bearing Capacity ◽  
Shear Failure ◽  
Control Sample ◽  
Variable Parameter ◽  
Rc Beams ◽  
Maximum Width ◽  
Shear Span ◽  
Initial Load ◽  
Inclined Cracks

This research paper present the experimental study of reinforce concrete beams strengthened by FRCM system in the shear area. All samples are without transverse reinforcement at the shear distance. First beams tested as control sample, with shear distance a/d=2. Another three beams tested with strengthening by FRCM system. Variable parameter is the level of initial load, before strengthening. The initial load values were 0, 0.3, 0.5 from carrying capacity of control samples. All RC beams were designed to fail in shear, even strengthened samples. In the result of this research we determined that fracture toughness of RC beams increases with a decrease of span to the effective depth ratio. Results are comparable with the increasing of bearing capacity. The first inclined crack opend in mid-height cross section at the load 50 kN at an angle equal to 450 and it does not depend on the shear span. The maximum width of inclined cracks decrease with decreasing of shear span. The maximum width of inclined cracks decrease with decreasing of the shear span. The maximum values of width of inclined cracks are fixed at the value of 0.55 - 0.85 mm. Using the limit crack opening width as criteria of exhaustion of serviceability (SLS) we saw that about 16 - 29% of bearing capacity still remains before the danger of shear failure of the beam.

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