scholarly journals Numerical Study of Using FRP and Steel Rebars in Simply Supported Prestressed Concrete Beams with External FRP Tendons

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2773
Author(s):  
Miao Pang ◽  
Zhangxiang Li ◽  
Tiejiong Lou
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Numerical Study ◽  
Fiber Reinforced Polymer ◽  
Simply Supported ◽  
Reinforced Polymer ◽  
Unbonded Tendons ◽  
Model Predictions ◽  
Steel Rebars ◽  
Gfrp Rebars

This study aimed at examining the feasibility of using fiber-reinforced polymer (FRP) rebars instead of steel ones in prestressed concrete beams (PCBs) with external FRP tendons. By applying an experimentally validated program, numerical tests were performed on simply supported PCBs, with investigated variables including rebars’ type and area. Three types of rebars were considered, i.e., carbon, glass FRPs (CFRP, GFRP), and reinforcing steel. The ratio of tensile rebars ranged from 0.22% to 2.16%. The results indicated that the beams with CFRP rebars exhibited better crack mode and higher ultimate load than the beams with GFRP or steel rebars. GFRP rebars led to considerably higher ultimate deflection and tendon stress increment than steel rebars. In addition, several models for calculating the ultimate stress in unbonded tendons were assessed. An analytical model was also proposed to predict the tendon stress at ultimate and flexural strength in externally PCBs with steel and FRP rebars. The model predictions agreed well with the numerical results.

Experimental Studies on High Strength Concrete Beams Reinforced with Steel and GFRP Rebars

2012 ◽  
Vol 238 ◽  
pp. 669-673 ◽  
Author(s):  
Ying Hao Liu ◽  
Yong Yuan
Keyword(s):  
High Strength Concrete ◽  
Experimental Studies ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Structural Behavior ◽  
Strength Concrete ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Steel Rebars ◽  
Gfrp Rebars

The paper analyzes the structural behavior of high strength concrete (HSC) beams reinforced with hybrid glass fiber reinforced polymer (GFRP) and steel reinforcements. The analysis refers to HSC beams reinforced with GFRP rebars and steel rebars placed in different layers. Results of the experimental and theoretical investigation are represented and discussed. Significant features of the structural behavior regarding flexural strength, deflection, are pointed out.

scholarly journals Experimental investigation on the seismic behavior of concrete beams with prestressing carbon fiber reinforced polymer tendons

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041988523
Author(s):  
Zuohu Wang ◽  
Zhanguang Gao ◽  
Yuan Yao ◽  
Weizhang Liao
Keyword(s):  
Carbon Fiber ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Ductility Index ◽  
Reinforced Polymer ◽  
Energy Dissipation Capacity ◽  
Carbon Fiber Reinforced

Seven prestressed concrete beams and one normal concrete beam were tested to study the seismic performance of concrete beams with prestressing carbon fiber reinforced polymer tendons. The failure modes, hysteretic curves, ductility, stiffness degeneration, and energy dissipation capacity were studied systematically. This study shows that the partial prestressing ratio is the main factor that affects the seismic performance of carbon fiber reinforced polymer prestressed concrete beams. The beam is more resilient to seismic loads as the partial prestressing ratio decreases. Under the same partial prestressing ratio value, the energy dissipation capacity of prestressed concrete beams with unbonded carbon fiber reinforced polymer tendons was better than that of prestressed beams with bonded carbon fiber reinforced polymer tendons. When combining both bonded and unbonded prestressing carbon fiber reinforced polymer tendons, the ductility index of concrete beams was improved. Compared with that of fully unbonded and fully bonded carbon fiber reinforced polymer prestressed concrete beams, the ductility index of concrete beams with combined bonded and unbonded prestressing tendons increased by 26% and 12%, respectively.

scholarly journals Moment Redistribution in Continuous Externally CFRP Prestressed Beams with Steel and FRP Rebars

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1181
Author(s):  
Tiejiong Lou ◽  
Zhangxiang Li ◽  
Miao Pang
Keyword(s):  
Prestressed Concrete ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Concrete Cracking ◽  
Moment Redistribution ◽  
Reinforced Polymer ◽  
Negative Moment ◽  
Lower Moment ◽  
The Impact ◽  
Steel Rebars

This paper assesses the impact of adopting carbon- or glass-fiber-reinforced polymer (CFRP or GFRP) instead of steel rebars on the redistribution of moments in prestressed concrete beams (PCBs) with external CFRP tendons. A numerical program is introduced, and numerical simulations are performed on two-span continuous beams with steel, CFRP or GFRP rebars of various areas, i.e., Ar2 = 360–3560 mm2, and Ar1/Ar2 = 1.5, where Ar1 and Ar2 are areas of tensile rebars over the positive and negative moment zones, respectively. The results show the moment redistribution is contributed by concrete cracking only for the beams with fiber-reinforced polymer (FRP) rebars, and by concrete cracking and steel yielding for the beams with steel rebars. As a result, the use of FRP rebars leads to a substantially lower moment redistribution than in steel rebars. It is also demonstrated that Eurocode 2, CSA A23.3-04 and ACI 318-19 fail to reflect the rebar influence on moment redistribution in PCBs with external tendons. A simplified equation for the quantification of moment redistribution in externally PCBs with steel and FRP rebars is recommended, which yields accurate and conservative predictions.

Flexural Capacity of Concrete Beams Prestressed with Carbon Fiber Reinforced Polymer (CFRP) Tendons

2010 ◽  
Vol 168-170 ◽  
pp. 1353-1362 ◽  
Author(s):  
Xiu Li Du ◽  
Zuo Hu Wang ◽  
Jing Bo Liu
Keyword(s):  
Carbon Fiber ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Weight Ratio ◽  
Analytical Investigation ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Flexural Capacity ◽  
Reinforced Polymer ◽  
Prestressed Beam

Fiber reinforced polymer (FRP), particularly those incorporating carbon fiber (CFRP), has high strength, high stiffness-to-weight ratio and high resistance to corrosion, which shows potential for use as prestressing tendons in corrosive environment. However, concrete beams prestressed with FRP tendons have showed brittle flexural failure due to the elastic rupture of FRP tendons. In order to improve the ductility, a combination of bonded and/or unbonded prestressing tendons was used. Nine prestressed concrete beams were tested up to failure to study the effect of bonded and unbonded FRP tendons on their flexural capacity. Three factors were taken into consideration; the bonding condition of CFRP tendons, the location of CFRP tendons and the prestressing ratio. Also an analytical investigation was carried out to extend some flexural capacity calculation equations to this beam type. The results of the experimental showed that under the same condition, the carrying capacity of concrete beam prestressed with bonded FRP tendons was 20% higher than that of internal unbonded prestressed beam, and was 40% higher than that of external unbonded prestressed beam without deviators. By combination of bonded and unbonded FRP tendons, the ductility of prestressed concrete beams can be improved.

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