Digital image correlation-based experimental stress analysis of reinforced concrete beams, strengthened using carbon composites
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Abstract
- The strengthening of reinforced concrete beams through the use of epoxy-bonded carbon composites has been widely researched in the United States since 1991. Despite the widespread attention of researchers, however, there are no reliable methods of predicting the failure of the repaired and strengthened beams by peeling of the fiber reinforced polymer (FRP) material from the parent concrete. To better understand peeling failure, several investigators have presented analytical work to predict the distribution of stresses along the interface between the FRP and the concrete. Several closed-form solutions can be found in the literature to predict the levels of shear stress present between the bonded composite plate and the parent concrete beam. However, there has been very little experimental verification of these analytical predictions because few experiments on large-scale beams have had sufficient instrumentation to facilitate the comparison. Some experiments have been presented(1) in which electrical resistance strain gages were placed along the length of the carbon plate in order to deduce the interfacial shear stress using first differences. This method, though very crude, demonstrated that there are substantial differences between the distributions of interfacial shear stresses in actual repaired beams versus the analytical predictions.
This paper presents a new test program in which large-scale carbon-fiber-strengthened reinforced concrete beams are load-tested to failure, while employing digital image correlation (DIC) to record the strains in the carbon fiber plate. Relying on the linear elasticity of carbon fiber, the interfacial shear can be determined and compared with the analytical predictions of the literature.
The focus of this paper is the presentation of the experimental shear stress distributions and comparisons of these distributions with previous results available in the literature.
| Title | Digital image correlation-based experimental stress analysis of reinforced concrete beams, strengthened using carbon composites |
|---|---|
| Creator | Helm, Jeffrey D. |
| Kurtz, Stephen J. | |
| Publisher | Proceedings of the SPIE |
| Academic Department | Mechanical Engineering |
| Division | Engineering |
| Organization | Lafayette College |
| Date Issued | 2005 |
| Date Available | 2015-10-01T19:51:56Z |
| Type | Article |
| Language | English |
| Keyword | reinforced concrete |
| fiber reinforced polymers | |
| digital image correlation | |
| stress analysis | |
| Bibliographic Citation | Helm, J. D. and S. J. Kurtz. (2005) "Digital image correlation-based experimental stress analysis of reinforced concrete beams, strengthened using carbon composites." Proceedings of the SPIE 5665: 40-50. |
| Standard Identifier | DOI 10.1117/12.586863 |
| Handle 10385/2038 | |
| Permalink | http://hdl.handle.net/10385/2038 |
| Rights Statement |
In Copyright
|
| Rights Holders | IS&T |
| SPIE |
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| File | Helm-ProceedingsoftheSPIE-vol5665-2005.pdf | Uploaded 2019-10-20 | Public | Download |
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