Stochasticity on Long-Term Behavior of Steel-/Carbon Fiber-Reinforced Polymer Prestressed Girders

2021 ◽  
Vol 118 (2) ◽  
Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 614 ◽  
Author(s):  
Arya Uthaman ◽  
Guijun Xian ◽  
Sabu Thomas ◽  
Yunjia Wang ◽  
Qiang Zheng ◽  
...  

The usage of polymer composites in various engineering fields has increased. However, the long-term service performance of such materials under aggressive conditions is still poorly understood, which limits the development of safe and economically effective designs. In this study, the aging of an epoxy resin and its carbon fiber-reinforced polymer (CFRP) composites upon immersion in water, acidic, and alkaline solutions was evaluated at different temperatures. The service life of the CFRP composites under various conditions could be predicted by the Arrhenius theory. The thermal and mechanical analysis results indicated that the CFRP composites were more vulnerable to HCl owing to the higher moisture absorption and diffusion of HCl into their cracks. The scanning electron microscopy results showed that the polymer matrix was damaged and degraded. Therefore, to allow long-term application, CFRP composites must be protected from acidic environments.


2017 ◽  
Vol 21 (4) ◽  
pp. 571-579 ◽  
Author(s):  
Bin Hong ◽  
Guijun Xian ◽  
Zike Wang

Pultruded carbon fiber reinforced polymer plates have been widely used for structural rehabilitation due to their excellent mechanical properties. Even though, the long-term durability performance of carbon fiber reinforced polymer plates is still a concern, especially when subjected to harsh environmental conditions (e.g. water immersion). In the present study, the effects of water immersion at 23°C, 40°C, and 60°C on the degradation of the pultruded carbon fiber reinforced polymer plates were investigated in terms of water uptake and mechanical properties. To elucidate the degradation mechanisms, the resin matrix and the fiber and resin adhesion were also assessed in the same conditions. The test results indicated that water immersion, especially at higher temperatures, leads to serious fiber debonding, and thus the carbon fiber reinforced polymer samples absorb much more water than the resin matrix. In addition, the transverse flexural strength of the carbon fiber reinforced polymer plates, closely correlated to the fiber–resin adhesion, reduced significantly at high temperatures. On the contrary, the resin matrix and carbon fiber reinforced polymer plates show much less degradation subjected to the same immersion conditions. Therefore, to comprehensively understand the long-term durability of a carbon fiber reinforced polymer material, it is necessary to test the variation of the bonding strength between fiber and resin matrix, in addition to the tensile performances in fiber directions of the carbon fiber reinforced polymer plates.


2019 ◽  
Vol 7 (1) ◽  
pp. 30-34
Author(s):  
A. Ajwad ◽  
U. Ilyas ◽  
N. Khadim ◽  
Abdullah ◽  
M.U. Rashid ◽  
...  

Carbon fiber reinforced polymer (CFRP) strips are widely used all over the globe as a repair and strengthening material for concrete elements. This paper looks at comparison of numerous methods to rehabilitate concrete beams with the use of CFRP sheet strips. This research work consists of 4 under-reinforced, properly cured RCC beams under two point loading test. One beam was loaded till failure, which was considered the control beam for comparison. Other 3 beams were load till the appearance of initial crack, which normally occurred at third-quarters of failure load and then repaired with different ratios and design of CFRP sheet strips. Afterwards, the repaired beams were loaded again till failure and the results were compared with control beam. Deflections and ultimate load were noted for all concrete beams. It was found out the use of CFRP sheet strips did increase the maximum load bearing capacity of cracked beams, although their behavior was more brittle as compared with control beam.


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