Innovative mechanical device for the post-tensioning of glass fiber reinforced polymer bars for masonry type retrofit applications
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A mechanical device specially designed for the application of low-level post-tensioning forces to glass fiber reinforced polymer (GFRP) bars has been developed at the University of Missouri-Rolla. Some of the advantageous features of this device are that it is simple to assemble and the low-level post-tensioning forces can be applied manually and safely without the need for hydraulic jacks or heavy equipment. This device has been conceived with the main objective of retrofitting masonry buildings, some of which remain in service despite large, open cracks leading to considerable instability and serviceability concerns. According to the method derived in this paper, GFRP bars are installed in artificially imposed grooves and then post-tensioned with low-level stresses with the main objective to partially close these cracks, such that the serviceability and in-plane capacity of un-reinforced masonry (URM) buildings may be regained. In this paper we describe the mechanical components of this device, along with its advantageous features and potential application for the retrofit of URM walls.
Key WordsAnchorage GFRP bar masonry wall post-tensioning prestressing thermoplastics
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- 1.Dolan, C.W., Bakis, C.E., Nanni, A., and Munley, E., “Prestressed Concrete with FRP Composites,” Proceeding of the 3rd International Conference on Advanced Composite Materials in Bridges and Structures, J. Humar and A.G. Razaqpur, editors, Ottawa, Canada, 379–386 (2000).Google Scholar
- 2.Erki, M.A. andRizkalla, S.H., “Anchorages for FRP Reinforcement,”Concrete International,15 (6),54–59 (1993).Google Scholar
- 3.Al-Mayah, A., Soudki, K.A., andPlumtree, A., “Experimental and Analytical Investigation of a Stainless Steel Anchorage for CFRP Prestressing Tendons,”PCI Journal,46 (2),88–100 (2001).Google Scholar
- 4.Wolff, R. andMiesseler, H.J., “Glass Fiber Prestressing System,”Fiber-Reinforce-Plastic (FRP) for Concrete Structures: Properties and Applications, A. Nanni, editor, Elsevier Science, New York, 305–332 (1993).Google Scholar
- 5.Burgeoyne, C.J., “Parafil Ropes for Prestressing Applications, Fiber-Reinforce-Plastic (FRP) for Concrete Structures: Properties and Applications, A. Nanni, editor, Elsevier Science, New York, 333–351 (1993).Google Scholar
- 6.Nanni, A., Bakis, C.E., O'Neil, E.F., andDixon, T.O., “Performance of FRP Tendon-Anchorage Systems for Prestressed Concrete Structures,”PCI Journal,41 (1),34–44 (1996).Google Scholar
- 7.Vanderpool, D.R., Micelli, F., and Nanni, A., “Thermoplastic Rebar: Performance and Applications,” Proceedings of CCC 2001, Composites in Construction, Porto, Portugal, J. Figuerias, L. Juvandes and R. Furia, editors, 153–157 (2001).Google Scholar
- 8.Casareto, M., Oliveri, A., and Romelli, A., “Strengthening of Masonry: Opportunities and Challenges in the Use of Composites—Rinforzo della Muratura: Campi di Applicazione e Prospettive nell'Utilizzo dei Materiali Compositi,” Thesis, Department of Structural and Geotechnical Engineering, University of Genoa, 205–233 (2002).Google Scholar
- 9.Lorenzis, L.D., Nanni, A., and Tegola, A.L., “Bond of Near Surface Mounted FRP rods in Concrete Masonry Units,” Proceedings of the 7th Annual International Conference on Composites Engineering (ICCE/7), Denver, CO, 3–4 (2000).Google Scholar
- 10.Tumialan, J.G., Huang, P-C, Nanni, A., and Silva, P., “Strengthening of Masonry Walls by FRP Structural Repointing,” Proceedings of the 5th International Conference on FRP Reinforced Concrete Structures (FRPRCS-5), Cambridge, UK, 1033–1042 (2001).Google Scholar
- 11.ACI Committee 440, “Guide for the Design and Construction of Concrete Reinforced with FRP Bars (ACI 440, 1R-01),” American Concrete Institute, 22–23 (2001).Google Scholar