Impact of curvature type on the behavior of slender reinforced concrete rectangular column confined with CFRP composite

2019 ◽  
Vol 173 ◽  
pp. 106939 ◽  
Author(s):  
Rajai Z. Al-Rousan ◽  
Muneer H. Barfed
Keyword(s):  
Reinforced Concrete ◽  
Cfrp Composite ◽  
Curvature Type

Experimental analysis of reinforced concrete shear deficient beams with circular web openings strengthened by CFRP composite

2020 ◽  
Vol 249 ◽  
pp. 112561 ◽  
Author(s):  
Ceyhun Aksoylu ◽  
Şakir Yazman ◽  
Yasin Onuralp Özkılıç ◽  
Lokman Gemi ◽  
Musa Hakan Arslan
Keyword(s):  
Reinforced Concrete ◽  
Experimental Analysis ◽  
Web Openings ◽  
Cfrp Composite

Laboratory Tests and Numerical Simulations of CFRP Strengthened RC Pier Subjected to Barge Impact Load

2015 ◽  
Vol 15 (02) ◽  
pp. 1450037 ◽  
Author(s):  
Yanyan Sha ◽  
Hong Hao
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Impact Load ◽  
Numerical Models ◽  
Impact Resistance ◽  
Bridge Piers ◽  
Impact Loads ◽  
Bridge Structures ◽  
Cfrp Composite ◽  
Vessel Impact

Bridge piers are designed to withstand not only axial loads of superstructures and passing vehicles but also out-of-plane loads such as earthquake excitations and vessel impact loads. Vessel impact on bridge piers can lead to substantial damages or even collapse of bridge structures. An increasing number of vessel collision accidents have been reported in the past decade. A lot of researches have been conducted for predicting barge impact loads and calculating structural responses. However, in practice it is not possible to design bridge structures to resist all levels of barge impact loads. Moreover, with an increasing traffic volume and vessel payload in some waterways, the bridge piers designed according to previous specifications might not be sufficient to resist the current vessel impact loads. Therefore, strengthening existing bridge piers are sometimes necessary for protecting structures from barge impact. Carbon fiber reinforced polymer (CFRP) has been widely used in strengthening reinforced concrete structures under impulsive loadings. It is an effective material which has been proven to be able to increase the flexural strength of structures. In this study, CFRP composites are used to strengthen reinforced concrete piers against barge impact loads. Pendulum impact tests are conducted on scaled pier models. Impact force and pier response with and without CFRP strengthening are compared. The effectiveness of using CFRP strengthening the pier model is observed. In addition, numerical models of the bridge piers are developed and calibrated with experimental results. Parametric simulations of barge impacting on piers with or without CFRP strengthening are carried out. The results show that compared with unstrengthened pier, CFRP composite strengthened bridge pier has a higher impact resistance capacity and hence endures less structural damage under the same barge impact load. The effectiveness of CFRP strengthening with different CFRP thickness, CFRP strength and bond strength between the pier and the CFRP composite are also discussed.

Laminated Composite Beam with Bonded CFRP Reinforcement Stress Performance Analysis

2012 ◽  
Vol 204-208 ◽  
pp. 3160-3163
Author(s):  
Yong Wei Wang ◽  
Yan Qin Guo ◽  
Hong Xia Li
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beam ◽  
Laminated Composite ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Rc Beam ◽  
Essential Difference ◽  
Cfrp Composite ◽  
Laminated Layer

Based on the test of 7 reinforced concrete beam reinforcement test data comparison analysis shows that only the ordinary reinforced concrete beams with externally bonded CFRP, effectively improve the bearing capacity of members, but due to the lower tensile reserves and the upper compression reserve is relatively insufficient, make a component similar over-reinforced beam brittle failure, its ultimate bearing capacity was significantly lower than the upper part at the same time a laminated layer of the RC beam. Laminated paste CFRP composite reinforced RC beam damage characteristics and common reinforced concrete beam was no essential difference, but the laminated layer thickness reaches to a certain degree, the CFRP can also occur with sudden local cleavage fracture.

Experimental Study of Corroded RC Beams Strengthened with CFRP under Fatigue and Monotonic Loads

2011 ◽  
Vol 243-249 ◽  
pp. 142-148
Author(s):  
Lei Wang ◽  
Jin Xiu Liang
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Composite Laminates ◽  
Load Capacity ◽  
Experimental Studies ◽  
Corrosion Damage ◽  
Fatigue Loading ◽  
Reinforced Concrete Beams ◽  
Ultimate Load Capacity ◽  
Cfrp Composite

This paper summarizes the results and discussion of experimental studies on corroded, reinforced concrete 4 point beam test specimens (120 mm x 200 mm x 1700 mm) repaired by external bonding of carbon fiber reinforced polymer (CFRP) composite laminates to the tensile face of the beam. The primary parameters investigated in this experimental study were distortion, stress distribution, and ultimate load capacity of the corroded reinforced concrete beams. The results indicate that the load capacity and the rigidity of repaired corroded beams by CFRP were significantly higher than the un-repaired, corroded beams. Beams with a low degree of corrosion damage, repaired by CFRP, were still able to demonstrate good mechanical properties after a short-term fatigue loading.

Performance of Reinforced Concrete Beams Strengthened with CFRP Composite in Corrosive Environment

2011 ◽  
Vol 250-253 ◽  
pp. 3706-3714
Author(s):  
Piya Chotickai ◽  
Wasin Chimmanee
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Salt Water ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Corrosive Environment ◽  
Mode Of Failure ◽  
Cfrp Composite ◽  
Concrete Interface

The long-term performance of reinforced concrete beams externally strengthened with CFRP composite was evaluated in the present study. The load-carrying capacity and failure mechanism of the beams subjected to different durations in a corrosive environment were examined using four-point bending test. A total of five reinforced concrete beams externally strengthened with CFRP composite were exposed to wet/dry cycles in salt water for 0, 90, 240, and 360 days before tested to failure. The experimental results revealed that the midspan debonding was the dominant mode of failure. The debonding at the CFRP-concrete interface was detected after flexural cracks were developed in the concrete members. The characteristics of the load-deflection curves were relatively similar for all tested beams. The aggressive environment however had the detrimental effects on reducing the bond strength and fracture energy at the CFRP-concrete interface. Additionally, the mode of failure was altered from debonding failure in concrete substrate to failure in the interface epoxy when the beams were exposed to wet/dry cycles. The research findings provided the long-term effectiveness of the CFRP strengthening system in a corrosive environment.

scholarly journals Degradation of the EBR-CFRP strengthening system applied to reinforced concrete beams exposed to weathering

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Gláucia Maria Dalfré ◽  
Guilherme Aris Parsekian ◽  
Douglas da Costa Ferreira
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Natural Aging ◽  
Outdoor Exposure ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Externally Bonded ◽  
Cfrp Composite

Abstract Little is known about the behavior and durability of strengthening systems applied on concrete substrata and the possible loss of performance due to the degradation of the intervening materials by the structure’s natural aging process and exposure of the externally strengthened elements to aggressive environments. In this context, the present work presents an experimental analysis of the behavior of reinforced concrete beams strengthened with Carbon Fiber Reinforced Polymer (CFRP), applied according to the Externally Bonded Reinforcement (EBR) technique, maintained in a laboratory environment (indoor and protected) or exposed to weathering (outdoor exposure). In addition, specimens of the intervenient materials were also molded and exposed to the same environmental conditions as the beams. The results indicate that weather-exposed epoxy adhesives present reductions up to 70% in their mechanical properties after exposure, while the CFRP composite properties remain similar. It was also found that the strengthening system provided 50% and 28% increments in the load-carrying capacity and stiffness of the elements, respectively. However, the tests conducted after 6 months of weathering exposure showed a 10% reduction in the load-carrying capacity of the strengthened elements.

scholarly journals Study on the potential change of corroded reinforced concrete in ECE with MPC-CFRP as anode

2020 ◽  
Vol 319 ◽  
pp. 06005
Author(s):  
Yue Li ◽  
Xiuhu Zhang ◽  
S.M.Ali S. Hejazi
Keyword(s):  
Composite Material ◽  
Reinforced Concrete ◽  
Current Density ◽  
Good Effect ◽  
Steel Bar ◽  
Steel Bars ◽  
Cfrp Composite ◽  
Current Densities ◽  
Electrochemical Chloride Extraction ◽  
Corrosion Of Steel

Aiming at the rust removal requirements of reinforced concrete, the MPC-CFRP composite material was used as the external anode, and the Electrochemical chloride extraction (ECE) method was used to test the polarization curve of the steel bar under different ECE current densities, and the potential changes of the steel bar at different times were analyzed. The results show that the ECE system with MPC-CFRP as the external anode has a good effect of reducing the corrosion rate and the risk of corrosion of steel bars. The current density of 3A/m2is higher than that of 1A/m2in dechlorination efficiency. After 28 days of ECE, the current density of 1A/m2and 3A/m2can re passivate the reinforcement.

scholarly journals Compressive Behaviour of RC Column with Fibre Reinforced Concrete Confined by CFRP Strips

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
A. M. Vasumathi ◽  
K. Rajkumar ◽  
G. Ganesh Prabhu
Keyword(s):  
Reinforced Concrete ◽  
Fibre Reinforced Concrete ◽  
Axial Deformation ◽  
Structural Behaviour ◽  
Deformation Control ◽  
Rc Column ◽  
Frp Composites ◽  
Externally Bonded ◽  
Earthquake Resistant Structures ◽  
Cfrp Composite

The structural application of synthetic fibre reinforced concrete (FRC) has become widespread in the construction industry in order to satisfy the requirement of the earthquake resistant structures. Research conducted so far are focused on the structural behaviour of RC column externally confined with FRP composites, while studies are needed to address the behaviour of FRP strengthened RC column fabricated using fibre reinforced concrete. With the intention that the experimental investigation was carried out to evaluate the feasibility use of CFRP composite strips in strengthening of RC column made with fibre reinforced concrete. Circular synthetic Polypropylene fibre was used in the rate of 0.50% in the volume of concrete. CFRP strips having a width of 50 mm were used to confine the column and the experimental parameters were effective spacing between the CFRP strips (20 mm and 30 mm) and the number of CFRP layers (one, two and three). The externally bonded CFRP strips counteract the lateral expansion of the concrete significantly by providing restraining effect and thus effect enhanced the stiffness of the column. The column strengthened with CFRP strips showed a maximum of 198.87% and 91.75% enhancement in axial deformation control and ultimate strength, respectively, compared to that of reference column. From the test results obtained, it is suggested that CFRP strips with the spacing of 20 mm and 30 mm can be used in strengthening of RC column made with FRC; however the column confined with 30 mm spacing provides an economical advantage compared to that of 20 mm spacing.

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