The Flexural Performance of Pre-Damaged Reinforced Concrete Beam Strengthened with CFRP in Seawater Environment

2012 ◽  
Vol 166-169 ◽  
pp. 1736-1739
Author(s):  
Yu Tian Wang ◽  
Xiu Li Du ◽  
Fu Xiang Jiang ◽  
Wei Zhang
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Strengthening Effect ◽  
Flexural Capacity ◽  
Flexural Performance ◽  
Seawater Environment

Experiments on flexural behavior of strengthened pre-damaged reinforced concrete beams with CFRP and those exposed to seawater for different time have been carried out. By comparison, the rule of seawater effecting on failure modes of beams, fissure condition, strain development and flexural capacity, and so on have been studied. The results show that reinforcement treatment on the mechanical damaged reinforced concrete beams with bonding CFRP can effectively improve their flexural capacity and stiffness, and constrain the development of cracks. With the extension of time under seawater environment, although performance of pre-damaged beam strengthened with CFRP is influenced significantly, the strengthening effect is still more reliable.

scholarly journals Experimental Study on the Flexural Behavior of over Reinforced Concrete Beams Bolted with Compression Steel Plate: Part I

2020 ◽  
Vol 10 (3) ◽  
pp. 822 ◽  
Author(s):  
Shatha Alasadi ◽  
Payam Shafigh ◽  
Zainah Ibrahim
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Plate ◽  
Concrete Beams ◽  
Peak Load ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Steel Plates ◽  
Flexural Behavior ◽  
Flexural Stiffness

The purpose of this paper is to investigate the flexural behavior of over-reinforced concrete beam enhancement by bolted-compression steel plate (BCSP) with normal reinforced concrete beams under laboratory experimental condition. Three beams developed with steel plates were tested until they failed in compression compared with one beam without a steel plate. The thicknesses of the steel plates used were 6 mm, 10 mm, and 15 mm. The beams were simply supported and loaded monotonically with two-point loads. Load-deflection behaviors of the beams were observed, analyzed, and evaluated in terms of spall-off concrete loading, peak loading, displacement at mid-span, flexural stiffness (service and post-peak), and energy dissipation. The outcome of the experiment shows that the use of a steel plate can improve the failure modes of the beams and also increases the peak load and flexural stiffness. The steel development beams dissipated much higher energies with an increase in plate thicknesses than the conventional beam.

scholarly journals Study on the Flexural Performance of Hybrid-Reinforced Concrete Beams with a New Cathodic Protection System Subjected to Corrosion

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 234 ◽  
Author(s):  
Yingwu Zhou ◽  
Yaowei Zheng ◽  
Lili Sui ◽  
Biao Hu ◽  
Xiaoxu Huang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Steel Corrosion ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Flexural Performance ◽  
Reinforced Polymer ◽  
Steel Bar

Steel corrosion is considered as the main factor for the insufficient durability of concrete structures, especially in the marine environment. In this paper, to further inhibit steel corrosion in a high chloride environment and take advantage of the dual-functional carbon fiber reinforced polymer (CFRP), the impressed current cathodic protection (ICCP) technique was applied to the hybrid-reinforced concrete beam with internally embedded CFRP bars and steel fiber reinforced polymer composite bar (SFCB) as the anode material while the steel bar was compelled to the cathode. The effect of the new ICCP system on the flexural performance of the hybrid-reinforced concrete beam subjected to corrosion was verified experimentally. First, the electricity-accelerated precorrosion test was performed for the steel bar in the hybrid-reinforced beams with a target corrosion ratio of 5%. Then, the dry–wet cycles corrosion was conducted and the ICCP system was activated simultaneously for the hybrid-reinforced concrete beam for 180 days. Finally, the three-point bending experiment was carried out for the hybrid-reinforced concrete beams. The steel bars were taken out from the concrete to quantitatively measure the corrosion ratio after flexural tests. Results showed that the further corrosion of steel bars could be inhibited effectively by the ICCP treatment with the CFRP bar and the SFCB as the anode. Additionally, the ICCP system showed an obvious effect on the flexural behavior of the hybrid-reinforced concrete beams: The crack load and ultimate load, as well as the stiffness, were enhanced notably compared with the beam without ICCP treatment. Compared with the SFCB anode, the ICCP system with the CFRP bar as the anode material was more effective for the hybrid-reinforced concrete beam to prevent the steel corrosion.

scholarly journals Flexural Behavior of Reinforced Concrete Beams Retrofitted with Modularized Steel Plates

2021 ◽  
Vol 11 (5) ◽  
pp. 2348
Author(s):  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Steel Plates ◽  
Flexural Behavior ◽  
Element Analysis ◽  
Flexural Performance ◽  
Structural Capacity

Many structural retrofitting methods tend to only focus on how to improve the strength and ductility of structural members. It is necessary for developing retrofitting strategy to consider not only upgrading the capacity but also achieving rapid and economical construction. In this paper, a new retrofitting details and technique is proposed to improve structural capacity and constructability for retrofitting reinforced concrete beams. The components of retrofitting are prefabricated, and the components are quickly assembled using bolts and chemical anchors on site. The details of modularized steel plates for retrofitting have been chosen based on the finite element analysis. To evaluate the structural performance of concrete beams retrofitted with the proposed details, five concrete beams with and without retrofitting were tested. The proposed retrofitting method significantly increased both the maximum load capacity and ductility of reinforced concrete beams. The test results showed that the flexural performance of the existing reinforced concrete beams increased by 3 times, the ductility by 2.5 times, and the energy dissipation capacity by 7 times.

scholarly journals Flexural performance of reinforced concrete beams made with locally sourced fly ash

2021 ◽  
Vol 15 (2) ◽  
pp. 38-50
Author(s):  
Nguyen Van Chinh
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Portland Cement ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Performance ◽  
Steel Bars ◽  
Cracking Pattern

The paper investigates the flexural performance of reinforced concrete beams in which fly ash from Vinh Tan power station was used to replace original Portland cement in the proportions of 0%, 10%, 20% and 40% by weight. Twelve reinforced concrete beams with the dimensions of 100×150 mm in cross section and 1000 mm in length were cast and cured in water. These beams were flexurally tested under 4 points bending at 28 days, 56 days and 90 days. Load deflection curves, first cracking load, yielding of steel bars, ultimate load, and cracking pattern of the reinforced concrete beams are used to investigate the performance of the control and fly ash beams at 28 days, 56 days and 90 days. The results show that locally sourced fly ash does not affect the load and deflection curves. Fly ash reduced slightly the flexural strength of reinforced concrete beams at 90 days when 40% of fly ash was used to replaced Portland cement. Keywords: fly ash; reinforced concrete beam; flexural performance; load; deflection.

Mechanical performance of CFRP enclosed reinforced concrete beams by different shear reinforcement

2020 ◽  
pp. 136943322097478
Author(s):  
Qi Cao ◽  
Jiadong Bao ◽  
Changjun Zhou ◽  
Xianrui Lv
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Concrete Beams ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Shear Reinforcement ◽  
Four Point Bending ◽  
Expansive Agent

This paper aims to study the flexural behavior of CFRP enclosed reinforced concrete beams with different shear reinforcement. Four-point bending tests were carried out on six concrete beams with different contents of steel fibers (0.5%, 1.0%, and 1.5%) as well as six beams with different stirrup spacing (100 mm, 150 mm, and 300 mm) without fiber. The effect of steel fiber (SF) content as well as stirrup spacing on flexural properties of concrete beams were investigated. Meanwhile, the effect of expansive agent on the properties of specimens was also studied. The data collected in this test include cracking load, ultimate load, mid-span deflection, strain of CFRP (Carbon fiber reinforced polymer), strain of longitudinal steel reinforcement as well as the failure modes. Test results show that both cracking loads and ultimate loads of the SF reinforced beam specimens are generally higher than those of the corresponding stirrup reinforced beam specimens. Experimental results also indicate that the addition of SF can improve the ductility and cracking resistance of specimens. This therefore demonstrates that it is feasible to replace stirrup reinforcement with SF as shear reinforcement. In addition, it exhibits a good agreement between experimental results and analytical predictions in cracking loads and ultimate loads.

An Experimental Study on Flexural Behavior of Reinforced Concrete Beams with GFRP Bars and Recycled Coarse Aggregate

2013 ◽  
Vol 319 ◽  
pp. 440-443
Author(s):  
Seung Hun Kim ◽  
Yong Taeg Lee ◽  
Tae Soo Kim ◽  
Seong Uk Hong
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Flexural Performance ◽  
Coarse Aggregates ◽  
Glass Fiber Reinforced ◽  
Load Carrying ◽  
Cracking Pattern

This study evaluates the flexural performance of reinforced concrete beams with GFRP(Glass Fiber Reinforced Polymer) bars and RCA(Recycled Coarse Aggregates). A total of four specimens with various replacement ratios of RCA (0%, 30%, 50%, and 100%) were tested. An investigation was performed on the influence of RCA with various replacement ratios on load-carrying capacity, post cracking stiffness, cracking pattern, and ductility. The test results showed that replacement ratios of RCA had not a bad effect on concrete compressive strength or flexural strength of beams. They were compared with the design flexural strength and the nominal moment predictions of ACI Code.

scholarly journals Finite element modeling of flexural behavior of reinforced concrete beams externally strengthened with CFRP sheets

2021 ◽  
Vol 16 (59) ◽  
pp. 62-77
Author(s):  
Mahmoud Madqour ◽  
Khalid Fawzi ◽  
Hilal Hassan
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Element Model ◽  
Point Load ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Flexural Capacity ◽  
Cfrp Sheets ◽  
Cfrp Sheet

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.

scholarly journals Behaviour of Reinforced Concrete Beams With Circular Transverse Openings Under Static Loads

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ling Jen Hua ◽  
Howe Sheng Tang ◽  
Wen Kam Leong ◽  
How Teck Sia
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Equation Model ◽  
Point Load ◽  
Load Test ◽  
Reinforced Concrete Beams ◽  
Structural Behaviour ◽  
Beam Height

Transverse opening in a reinforced concrete beam allows the crossing of mechanical and electrical services through the beam. However, it affects the strength of a beam. Understanding its structural behaviour is crucial to ensure a safe design of the beam. For that, an experimental study was carried out on reinforced concrete beams with circular transverse openings. The four-point load test was conducted to study the effects of the size and the position of the opening on the beam performance under the shear and flexural loads. In addition, three reinforcing methods for the opening were tested. The beams were evaluated in terms of the load-displacement responses, mechanical properties, deflections, and failure modes. The opening with the diameter not exceeding 0.25 times beam height affected about 20% of beam strength (without reinforcements at the opening). The diagonal bar reinforcing method effectively restored the beam strength for the opening size not exceeding 1/3 of beam height. The equation model proposed conservatively predicted the ultimate capacity of the beam with a transverse opening.

Experimental Study on Flexural Behavior of Damaged Reinforced Concrete Beams Strengthened with CFRP

2014 ◽  
Vol 507 ◽  
pp. 306-310 ◽  
Author(s):  
Bin Jia ◽  
Jin Xue ◽  
Jun Mo ◽  
Chun Tao Zhang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Concrete Strength ◽  
High Strength ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Failure Model ◽  
High Coherence

Abstract. In the view of the project problem that concrete strength grade is lower than C15in reinforced concrete beam, we consider a composite technology strengthened with CFRP, and do some monotonic loading experiments on these beams with eight different methods, and discuss the beam force behavior including ultimate bearing capacity, failure model and crack propagation. This paper finds out that the composite reinforced scheme, which with ticking trough, planting steel displaces concrete and gluing and then pasting CFRP, has a remarkable improvement than pasting CFRP immediately, and that there is a high coherence workability in the old and new concrete, so we can give full play to their role as the CFRP high strength.

Calculation of Flexural Capacity of Steel Reinforced Concrete Beams Strengthened with FRP

2009 ◽  
Vol 79-82 ◽  
pp. 1141-1144
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Lan Lan Yan
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Design Method ◽  
Limit Equilibrium ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Capacity ◽  
Steel Reinforced Concrete ◽  
First Case

Based on earlier theoretical works on RC beams ,the mechanical properties of steel reinforced concrete beams strengthened with FRP(fiber reinforce polymer) are further investigated theoretically including theirs failure mechanism and loadability. According to the design method of reinforced concrete beam strengthened with FRP, steel reinforced concrete beam strengthened with FRP mainly can have three kinds of destruction patterns: the first case is the tensile steel yield, the tensile shaped steel yield, the FRP are put off, the compressive zone’s concrete has not crushed; the second case is the tensile steel yield, the tensile shaped steel yield, the FRP are put off; the compressive zone’s concrete has crushed; the last case is the tensile steel yield, the tensile shaped steel yield, the FRP are not put off, the compressive zone’s concrete has crushed. The second case is discussed in this paper.Based on the different position of middle axle and steel, steel concrete beams strengthened with FRP include: middle axle through the steel web, and not through the steel and just in steel compression flange . Aim at these three kind of situations, the stress are analysed. According to the stress patterns of steel reinforced concrete beams strengthened with FRP and different position between neutral axis and steel, the discriminant formula of the boundary destroys and the formula of cross-section flexural capacity calculation are put forward by using limit equilibrium theory.The formula is expressed clearly, simple and easy to use.The depth of compressive region is given in view of different failure types.

Sign in / Sign up

Export Citation Format

Share Document