Flexural behavior of reinforced concrete (RC) beams retrofitted with hybrid fiber reinforced polymers (FRPs) under sustaining loads

2011 ◽  
Vol 93 (2) ◽  
pp. 802-811 ◽  
Author(s):  
Hee Sun Kim ◽  
Yeong Soo Shin
Keyword(s):  
Reinforced Concrete ◽  
Flexural Behavior ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymers

Experimental and analytical investigation of using externally bonded, hybrid, fiber-reinforced polymers to repair and strengthen heated, damaged RC beams in flexure

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yousef Al Rjoub ◽  
Ala Obaidat ◽  
Ahmed Ashteyat ◽  
Khalid Alshboul
Keyword(s):  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymers ◽  
Content Type ◽  
Reinforced Polymer ◽  
Damaged Beams

PurposeThis study aims to conduct an experimental study and finite element model (FEM) to investigate the flexural behavior of heat-damaged beams strengthened/repaired by hybrid fiber-reinforced polymers (HFRP).Design/methodology/approachTwo groups of beams of (150 × 250 × 1,200) mm were cast, strengthened and repaired using different configurations of HFRP and tested under four-point loadings. The first group was kept at room temperature, while the second group was exposed to a temperature of 400°C.FindingsIt was found that using multiple layers of carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP) enhanced the strength more than a single layer. Also, the order of two layers of FRP showed no effect on flexural behavior of beams. Using a three-layer scheme (attaching the GFRP first and followed by two layers of CFRP) exhibited increase in ultimate load more than the scheme attached by CFRP first. Furthermore, the scheme HGC (heated beam repaired with glass and carbon, in sequence) allowed to achieve residual flexural capacity of specimen exposed to 400°C. Typical flexural failure was observed in control and heat-damaged beams, whereas the strengthened/repaired beams failed by cover separation and FRP debonding, however, specimen repaired with two layers of GFRP failed by FRP rupture. The FEM results showed good agreement with experimental results.Originality/valueFew researchers have studied the effects of HFRP on strengthening and repair of heated, damaged reinforced concrete (RC) beams. This paper investigates, both experimentally and analytically, the performance of externally strengthened and repaired RC beams, in flexure, with different FRP configurations of CFRP and GFRP.

Flexural Performance of Corroded RC Beams Strengthened with Hybrid Fiber Reinforced Polymers

2011 ◽  
Vol 243-249 ◽  
pp. 5618-5623
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng
Keyword(s):  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Rc Beam ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymers ◽  
Displacement Ductility ◽  
Flexural Performance ◽  
Reinforced Polymer

The research program is aimed at investigating the effectiveness of application of good ductile hybrid fiber reinforced polymer (FRP) to upgrade corroded RC beams. A total of 5 RC beams are tested under flexural load, the results show that compared with the un-strengthened corroded RC beam, the crack, yield, maximum and ultimate load of corroded RC beam strengthened with hybrid FRP sheets is increased by 14%, 35%, 102% and 109% respectively, and the displacement ductility factor is only decreased by 11%, which indicate that the hybrid FRP sheets can improve significantly the flexural performance of corroded RC beam.

scholarly journals Effect of Stirrups on Plate End Debonding in Reinforced Concrete Beams Strengthened with Fiber Reinforced Polymers

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3322
Author(s):  
Abdulaziz I. Al-Negheimish ◽  
Ahmed K. El-Sayed ◽  
Mohammed A. Al-Saawani ◽  
Abdulrahman M. Alhozaimy
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Failure Load ◽  
Design Guidelines ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Cfrp Sheets

Plate end (PE) debonding is one of the critical debonding failure modes that may occur in reinforced concrete (RC) beams strengthened with externally bonded fiber reinforced polymers (FRPs). This study investigated the effect of internal steel stirrups on the PE debonding failure load of FRP-strengthened RC beams. The dimensions of the beams were 3400 × 400 × 200 mm. The beams were strengthened with carbon FRP (CFRP) sheets bonded to the soffit of the beams. The beams were divided into two series based on the distance of the cutoff point of the CFRP sheets from the nearest support. This distance was 50 mm or 300 mm, and the amount of steel stirrups was varied in terms of varying the stirrup diameter and spacing. The beams were simply supported and tested under four-point bending. The test results indicate that the effect of stirrups on the load carrying capacity of the beams was more pronounced for the beams with CFRP sheets extended close to the supports. It was also indicated that beams with larger amounts of stirrups failed in PE debonding by concrete cover separation while beams with lower amounts of stirrups failed in PE by either PE interfacial debonding or critical diagonal crack-induced debonding. The beams were analyzed using several analytical models from design guidelines and the literature. The result of analysis indicates that most of the available models failed to reflect the effect of stirrups in predicting PE debonding failure load of the beams. On the other hand, the models of El-Sayed et al. and Teng and Yao were able to capture such an effect with the best predictions provided by El-Sayed et al. model.

Sign in / Sign up

Export Citation Format

Share Document