What the study found
The study found that a three-segment bonded anchorage system with variable stiffness performed well across temperatures from -20°C to 70°C. The best-performing configuration in the reported tests was LTC3, which showed higher equivalent shear stiffness and more uniform stress distribution than the other stiffness distributions.
Why the authors say this matters
The authors say variable-stiffness load transfer components, or LTCs, can reduce stress concentration in bonded carbon fiber-reinforced polymer anchors, and their results address how these systems behave across a wide temperature range. The study suggests this is relevant for improving anchorage efficiency and reducing damage in ribbed carbon fiber-reinforced polymer bar systems.
What the researchers tested
The researchers tested a three-segment bonded anchorage system using high-performance epoxy adhesive modified with 200-mesh quartz sand to adjust stiffness distribution. They carried out monotonic tensile tests on 62 specimens across three stiffness-ratio distributions (LTC1 to LTC3), three bond lengths (200 to 300 mm), and four temperatures (-20°C, 0°C, 20°C, and 70°C).
What worked and what didn't
At 20°C, LTC3 reached an average equivalent shear stiffness of 410.95 kN/mm, which was 1.84 times LTC1 and 1.68 times LTC2. At 70°C, stiffness dropped markedly, but LTC3 with a 250 mm bond length still maintained K = 60.00 kN/mm, kept shear stress more uniform, and showed anchorage efficiency above 95% across the tested temperatures. An optimized configuration with an outer diameter of 45 mm and a 1:2:3 segment ratio reduced stress concentration and lowered the matrix damage index by 16.6% at room temperature.
What to keep in mind
The abstract reports tests on a specific anchorage design, specimen set, and temperature range, so the findings are limited to those conditions. The available summary does not describe other limitations beyond the tested ranges and the need for finite element validation before parametric investigation.
Key points
- A three-segment variable-stiffness bonded anchorage was tested for ribbed CFRP bars.
- LTC3 had the highest reported equivalent shear stiffness at 20°C.
- Performance declined at 70°C, but LTC3 still kept anchorage efficiency above 95%.
- The optimized 45 mm outer diameter and 1:2:3 segment ratio reduced stress concentration.
- The matrix damage index fell by 16.6% at room temperature in the optimized case.
Disclosure
- Research title:
- Variable-stiffness anchors performed better at high and room temperatures
- Authors:
- Zheng Feng, Xu Ling, Chuanxi Li, Yonghui An
- Institutions:
- Guangxi University, Guangxi University, Guangxi University, Guangxi University, Yunnan Investment Group (China)
- Publication date:
- 2026-06-28
- DOI:
- 10.1002/pc.71343
- OpenAlex record:
- View
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