Seismic Performance of Corroded RC Circular Columns Strengthened with Hybrid Fiber Reinforced Polymers

2011 ◽  
Vol 266 ◽  
pp. 192-195
Author(s):  
Jian Hui Li ◽  
Zhao Zhong Chang ◽  
Ying Li ◽  
Zong Cai Deng

In order to research the seismic performance of strengthening corroded RC circular columns with hybrid Fiber Reinforced Polymer (FRP) sheets, ten RC columns were tested under cyclic load and constant axial. Test phenomena are described, experimental data are analyzed and compared, and the effect of the axial compression ratio and stirrup reinforcement ratio on the seismic behavior is studied. Results show that the corrosion of steel bars may introduce the brittle failure for RC columns in some extent, and the seismic performance can be enhanced effectively for RC columns strengthened with hybrid FRP. Ductility and energy dissipation are improved significantly, but the bearing capacity can be only increased within limits. When the degree of rebar corrosion is 5.1%, the maximum displacement ductility factor and accumulated energy dissipation of the strengthened corroded columns are 123% and 12.5 times larger respectively than that of the un-strengthened corroded columns.

2011 ◽  
Vol 255-260 ◽  
pp. 3124-3128
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng

Corroded RC columns do not possess necessary ductility to dissipate seismic energy during a major earthquake, the study investigates the use of hybrid fiber reinforced polymer (FRP) wrapping as a method of retrofitting non-ductile corroded RC columns, and a model to determine the envelope response of RC corroded columns strengthened with hybrid FRP are presented based on cross-section analysis for undamaged RC element. The results show that the technique of strengthening corroded RC column with hybrid FRP is quite effective, the envelope curve estimated using the linear plane assumption with modification by reinforcement slip model, may still be used as the envelope curve of RC corroded columns strengthened with hybrid FRP, a good agreement between analytical and experimental results is observed.


2011 ◽  
Vol 243-249 ◽  
pp. 5618-5623
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng

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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yousef Al Rjoub ◽  
Ala Obaidat ◽  
Ahmed Ashteyat ◽  
Khalid Alshboul

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.


PAMM ◽  
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Nicola Magino ◽  
Jonathan Köbler ◽  
Heiko Andrä ◽  
Matti Schneider ◽  
Fabian Welschinger

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