Long-Term Performance Prediction of GFRP Bar in Moist Concrete under Sustained Loads

2011 ◽  
Vol 255-260 ◽  
pp. 3119-3123 ◽  
Author(s):  
Jian Wei Huang
Keyword(s):  
Tensile Strength ◽  
Temperature Shift ◽  
Strength Loss ◽  
Sustained Load ◽  
Gfrp Bar ◽  
Sustained Loads ◽  
Reported Data ◽  
Long Term Performance ◽  
Term Performance

In this paper, the tensile strength retention of GFRP bars embedded in moist concrete under sustained loads is discussed on the basis of reported data. Long-term performance of GFRP bar is predicted by a newly developed model through time-temperature shift and time extrapolation approaches. Results indicated that higher temperature and longer exposure time result in more tensile strength loss of the sustained GFRP bar in moist concrete. Above certain temperature, GFRP bar in moist concrete with about 20% sustained load fails in rupture of GFRP bar for 75-year design lifetime. The temperature effect shall be taken into account in the design codes/guidelines.

scholarly journals Prediction of the Long-Term Performance and Durability of GFRP Bars under the Combined Effect of a Sustained Load and Severe Environments

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2341 ◽  
Author(s):  
Jianwei Tu ◽  
Hua Xie ◽  
Kui Gao
Keyword(s):  
Stress Level ◽  
Degradation Mechanism ◽  
Sustained Load ◽  
Research Results ◽  
Gfrp Bars ◽  
Sustained Loads ◽  
Long Term Performance ◽  
Term Performance ◽  
Durability Performance

With the continuous development of production technology, the performance of glass-fiber-reinforced polymer (GFRP) bars is also changing, and some design codes are no longer applicable to new materials based on previous research results. In this study, a series of durability tests were carried out on a new generation of GFRP bars in laboratory-simulated seawater and a concrete environment under different temperatures and sustained loads. The durability performance of GFRP bars was investigated by analysing the residual tensile properties. The degradation mechanism of GFRP bars was also analysed by scanning electronic microscopy (SEM). Furthermore, the long-term performance of GFRP bars exposed to concrete pore solution under different stress levels was predicted using Arrhenius theory. The research results show that the degradation rate of GFRP bars was increased significantly at a 40% stress level. By comparing the test results, design limits, and other scholars’ research results, it is demonstrated that the GFRP bars used in this test have a good durability performance. It is found that the main degradation mechanism of the GFRP bars is the debonding at the fiber-matrix interface. In the range test, the effects of a 20% stress level on the degradation of GFRP bars were not obvious. However, the long-term performance prediction results show that when the exposure time was long enough, the degradation processes were accelerated by a 20% stress level.

Investigation of bond between fibre-reinforced polymer bars and concrete under sustained loads

2006 ◽  
Vol 33 (11) ◽  
pp. 1426-1437 ◽  
Author(s):  
F Shahidi ◽  
L D Wegner ◽  
B F Sparling
Keyword(s):  
Reinforced Concrete ◽  
Sustained Load ◽  
Reinforcing Bars ◽  
Bond Slip ◽  
Reinforced Polymer ◽  
Sustained Loads ◽  
Fibre Reinforced Polymer ◽  
Term Performance ◽  
Frp Bars

Although the use of fibre-reinforced polymer (FRP) bars to replace steel in reinforced concrete is becoming more common, uncertainty remains concerning the long-term performance of FRP, including the effect of a sustained load on the bond between the FRP bars and the concrete. An experimental study was therefore undertaken to investigate the long-term durability of the bond for various types of bars embedded in concrete: one type of glass FRP, two types of carbon FRP, and conventional steel reinforcing bars. Pullout specimens were tested both statically to failure and under sustained loads for periods of up to 1 year while free-end slip was monitored. Results revealed lower short-term bond strengths for FRP bars relative to steel and significant variability in long-term bond-slip performance among FRP bars of different types. Post-testing investigations revealed damage to bar surfaces at the macroscopic level, as well as broken longitudinal fibres and damage to the surface coatings at the microscopic level.Key words: reinforced concrete, fibre-reinforced polymer (FRP), bond, creep, pullout, sustained loads.

An Investigation of Environmental Reduction Factor for GFRP Bar Used as Concrete Reinforcement in China

2011 ◽  
Vol 413 ◽  
pp. 399-403 ◽  
Author(s):  
Jian Wei Huang
Keyword(s):  
Reduction Factor ◽  
Fiber Reinforced Polymer ◽  
Rc Structures ◽  
Average Temperature ◽  
Reinforced Polymer ◽  
Gfrp Bar ◽  
Temperature Records ◽  
Long Term Performance ◽  
Term Performance

Currently, an environmental reduction factor (ERF) is incorporated in design codes/guidelines of Fiber Reinforced-Polymer (FRP) in reinforced concrete (RC) structures to account for the FRP long-term durability. Due to the lack of real time durability data, justification of the ERF is still necessitated. This paper presents a calibration of ERF for GFRP bar to be used in China on the basis of the prediction of GFRP long-term performance with monthly average temperature records from 32 major cities. Research results show that the ERF values vary from 0.49 to 0.58 at 100% R.H. exposure, while ERFs are greater than 0.70 for all cases being studied when R.H. is below 90%. On the basis of this study, ERF can be recommended as of 0.70 and 0.50 for application with R.H. <90% and moisture saturated exposures, respectively.

Material Factor for GFRP RC Structures in Canada

2013 ◽  
Vol 671-674 ◽  
pp. 1648-1651
Author(s):  
Jian Wei Huang
Keyword(s):  
Safety Margin ◽  
Design Codes ◽  
Degradation Mechanisms ◽  
Rc Structures ◽  
Gfrp Bar ◽  
Current Design ◽  
Material Factor ◽  
Long Term Performance ◽  
Term Performance

Degradation mechanisms of GFRP bar in real concrete are still not clear to civil engineers due to limited field applications. To avoid unsafe design, in current design codes a material factor is used to assure long-term safety of GFRP RC structures. This paper presents an assessment of material factors for GFRP bar as specified in Canadian Design Codes by predicting GFRP long-term performance with monthly average temperatures from 14 weather reporting stations in Canada. Results showed that the material factor varies from 0.57 to 0.61 for an application with 100% RH exposure, while a factor of 0.75 could be adequate for cases with exposure RH ≤90%. Considering the annual relative humidity across Canada, conclusion could be made that current factors in Canadian codes could provide sufficient safety margin.

scholarly journals Long-term performance of GFRP bars in concrete elements under sustained load and environmental actions

2018 ◽  
Vol 190 ◽  
pp. 20-31 ◽  
Author(s):  
Hamed Fergani ◽  
Matteo Di Benedetti ◽  
Cristina Miàs Oller ◽  
Cyril Lynsdale ◽  
Maurizio Guadagnini
Keyword(s):  
Sustained Load ◽  
Gfrp Bars ◽  
Environmental Actions ◽  
Long Term Performance ◽  
Term Performance ◽  
Concrete Elements

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance
Sign in / Sign up

Export Citation Format

Share Document