Next Article in Journal
Application of Pyrolysis Gas Chromatography/Mass Spectrometry in Lacquer Research: A Review
Next Article in Special Issue
Retrofitting Masonry Walls with Carbon Mesh
Previous Article in Journal
Modification of a Phenolic Resin with Epoxy- and Methacrylate-Functionalized Silica Sols to Improve the Ablation Resistance of Their Glass Fiber-Reinforced Composites
Previous Article in Special Issue
Epoxy Enhanced by Recycled Milled Carbon Fibres in Adhesively-Bonded CFRP for Structural Strengthening
Open AccessArticle

Prestressed CFRP Strips with Gradient Anchorage for Structural Concrete Retrofitting: Experiments and Numerical Modeling

1
Structural Engineering Research Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf 8600, Switzerland
2
Department of Civil Engineering, University of Salerno, via Giovanni Paolo II 132, Fisciano 84084, Italy
*
Author to whom correspondence should be addressed.
Michels, J.; Czaderski, C.; Martinelli, E.; Motavalli, M. RC Beams Strengthened with Prestressed CFRP Strips with Gradient Anchorage; In 2nd conference on Smart Monitoring, Assessment and Retrofitting of Civil Structures (SMAR), Istanbul, Turkey, 2013.
Polymers 2014, 6(1), 114-131; https://doi.org/10.3390/polym6010114
Received: 29 November 2013 / Revised: 23 December 2013 / Accepted: 24 December 2013 / Published: 6 January 2014
(This article belongs to the Special Issue Selected Papers from "SMAR 2013")
This paper presents a study on the load carrying capacity of reinforced concrete (RC) beams strengthened with externally bonded (EB) carbon fiber reinforced polymer (CFRP) strips prestressed up to 0.6% in strain. At the strip ends, the innovative gradient anchorage is used instead of conventional mechanical fasteners. This method, based on the epoxy resin’s ability to rapidly cure under high temperatures, foresees a sector-wise heating followed by a gradual decrease of the initial prestress force towards the strip ends. The experimental investigation shows a promising structural behavior, resulting in high strip tensile strains, eventually almost reaching tensile failure of the composite strip. Additionally, ductility when considering deflection at steel yielding and at ultimate load is satisfying, too. From a practical point of view, it is demonstrated that premature strip grinding in the anchorage zone is not beneficial. In addition, a non-commercial 1D finite element code has been enlarged to an EB reinforcement with prestressed composite strips. A bilinear bond stress-slip relation obtained in earlier investigations is introduced as an additional failure criterion to the code. The numerical code is able to almost perfectly predict the overall structural behavior. Furthermore, the calculations are used for comparison purposes between an initially unstressed and a prestressed externally bonded composite reinforcement. The increase in cracking and yielding load, as well as differences in structural stiffness are apparent. View Full-Text
Keywords: CFRP; structural retrofitting; externally bonded reinforcement; prestressing; gradient anchorage; experimental investigation; finite element model CFRP; structural retrofitting; externally bonded reinforcement; prestressing; gradient anchorage; experimental investigation; finite element model
Show Figures

Figure 1

MDPI and ACS Style

Michels, J.; Martinelli, E.; Czaderski, C.; Motavalli, M. Prestressed CFRP Strips with Gradient Anchorage for Structural Concrete Retrofitting: Experiments and Numerical Modeling. Polymers 2014, 6, 114-131.

Show more citation formats Show less citations formats

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Back to TopTop