Theoretical Analysis and Experiment Study on Ultimate Stress Increment of Externally Prestressed Tendons(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2015年01期
- Page:
- 27-34
- Research Field:
- Publishing date:
Info
- Title:
- Theoretical Analysis and Experiment Study on Ultimate Stress Increment of Externally Prestressed Tendons
- Author(s):
- LI Li-feng; LI Tie-kui
- School of Civil Engineering, Hunan University
- Keywords:
- externally prestressed beam; composite box girder with corrugated steel web; limit state; ultimate stress increment; bending experiment
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to study the mechanical properties of externally prestressed beams under bending failure process and ultimate stress increment of externally prestressed tendons, the authors comparatively analyzed the national standardized calculation methods at home and abroad on the ultimate stress increment of externally prestressed tendons, and designed two externally prestressed composite box girders with corrugated steel webs. Moreover, the flexural bearing capacity experiment of them was completed, and a nonlinear fullrangeanalysis program was developed to perform the flexural behavior analysis. The authors took the span to depth ratio as the main variable, considering the concrete strength, sectional reinforcement status, prestressing force of externally prestressed tendons, based on the plane section assumption. According to the beam section internal force equilibrium conditions in limit state, the simple calculation formulae of ultimate stress increment of externally prestressed tendons were established by increasing the compressed concrete area. 19 experiment beams were collected to verify the calculation formulae. The results show that the flexural failure in the whole process of externally prestressed composite beams is similar with the inner prestressed beams, but the externally prestressed tendons has not yielded when the beams collapse, the values of ultimate stress increment of externally prestressed tendons calculated by standardized formulae at home and abroad are much smaller than the experiment results, yet the values are equal to the results when ordinary steel yields. The ultimate stress increment of external prestressed tendons and midspan deflection are approximate linear relationship. The calculated results agree well with the experiment results, so the formula has a certain reference value.
Last Update: 2015-02-03