Experimental and Theoretical Study on Anchorage Loss of Prestressed CFRP-Reinforced Concrete Beams
Abstract
:1. Introduction
2. FEM Calculation and Theoretical Analysis
2.1. Mechanism of Anchorage Loss
2.2. Description FEM Model
2.3. Analysis of FEM Results
2.4. Theoretical Calculation Analysis
3. Experimental Study
3.1. Overview of Project
3.2. Results and Discussion
3.3. Theoretical Validation
4. Conclusions
- The FEM simulations revealed that the deformation of the connecting screw and the front end of the steel reaction frame accounts for approximately 95% of the total anchorage loss in a CFRP tendon–main beam connection system. The TCS was established based on the stress forms of these components, and the calculated results are consistent with the FEM analysis, indicating a high level of reliability.
- In the control group experiment, a CFRP tendon with a length of 12 m and a diameter of 12 mm, subjected to a prestress of 950 MPa, showed an anchorage loss of approximately 1.5% of the set prestress value, corresponding to an anchorage deformation of about 1 mm. Further studies indicated that the deformation magnitude is influenced by the prestress level, the dimensions of the steel reaction frame’s front end, the connecting screw length, and the thread gap values.
- The experimental results show relative discrepancies with both the FEM and theoretical results, attributed to gaps values between the threaded connections. A 2 mm gap at each threaded connection was identified, and this can be reduced by tightening the threads with external force. However, the influencing pattern of these gaps requires further investigation. After adjusting the calculation formulas, the error was controlled within approximately 5%, demonstrating higher precision.
- This study provides a comprehensive framework for accurately predicting and mitigating anchorage loss in externally prestressed CFRP tendons, with significant implications for future engineering applications.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Component | Material | Elastic Modulus (MPa) | Poisson Ratio |
---|---|---|---|
Steel reaction frame | Q235 | 210,000 | 0.2 |
Fixed nut | Grade 8.8 | 210,000 | 0.3 |
Connecting screw | Grade 8.8 | 210,000 | 0.3 |
Anchor | Q235 | 210,000 | 0.3 |
CFRP tendon | CFRP | 160,000 | 0.31 |
Component | Deformation (mm) | Proportion of Total Deformation (%) | |
---|---|---|---|
Front end of the steel reaction frame | 0.270822 | 41.09 | |
Fixed nut | 0.001575 | 0.24 | |
Connecting screws | (a) | 0.027201 | 54.87 |
(b) | 0.309988 | ||
(c) | 0.024496 | ||
Rear of anchor | 0.025051 | 3.8 | |
Total deformation | 0.659133 | / |
Group | CFRP Tendon Length (mm) | Prestress (MPa) | Connecting Screw Length (mm) | Side Panel Spacing (mm) | Fixed Nut Torque (N·m) |
---|---|---|---|---|---|
1 | 12,000 | 950 | 139 | 79 | / |
2 | 12,000 | 950 | 135 | 59 | 400 |
3 | 12,000 | 950 | 137 | 59 | / |
4 | 12,000 | 475 | 374 | 59 | 400 |
5 | 12,000 | 475 | 370 | 59 | / |
6 | 12,000 | 950 | 374 | 59 | 400 |
7 | 12,000 | 950 | 376 | 59 | / |
Group | (MPa) | (MPa) | (MPa) | Deformation (a/mm) |
---|---|---|---|---|
1 | 948.51 | 933.88 | 14.63 | 1.061 |
2 | 951.52 | 941.65 | 9.87 | 0.716 |
3 | 947.98 | 935.71 | 12.27 | 0.890 |
4 | 486.86 | 476.28 | 10.58 | 0.784 |
5 | 485.58 | 472.43 | 13.16 | 0.954 |
6 | 975.28 | 957.20 | 18.08 | 1.311 |
7 | 962.36 | 941.14 | 21.22 | 1.539 |
Group | Steel Reaction Frame | Connection Screw | Deformation | (MPa) |
---|---|---|---|---|
1 | 0.267 | 0.364 | 0.631 | 8.70 |
2 | 0.112 | 0.355 | 0.467 | 9.196 |
3 | 0.111 | 0.359 | 0.470 | 11.995 |
4 | 0.057 | 0.471 | 0.528 | 10.046 |
5 | 0.057 | 0.465 | 0.522 | 12.719 |
6 | 0.118 | 0.978 | 1.097 | 17.888 |
7 | 0.113 | 0.936 | 1.049 | 19.988 |
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Liu, Q.; Jiang, H.; Tao, G.; Zhuge, P. Experimental and Theoretical Study on Anchorage Loss of Prestressed CFRP-Reinforced Concrete Beams. Appl. Sci. 2024, 14, 6246. https://doi.org/10.3390/app14146246
Liu Q, Jiang H, Tao G, Zhuge P. Experimental and Theoretical Study on Anchorage Loss of Prestressed CFRP-Reinforced Concrete Beams. Applied Sciences. 2024; 14(14):6246. https://doi.org/10.3390/app14146246
Chicago/Turabian StyleLiu, Qinrui, Haozhe Jiang, Guocheng Tao, and Ping Zhuge. 2024. "Experimental and Theoretical Study on Anchorage Loss of Prestressed CFRP-Reinforced Concrete Beams" Applied Sciences 14, no. 14: 6246. https://doi.org/10.3390/app14146246