Title:
Flexural Strengthening of RC Beams with GFRP Grid Reinforced Polymer
Author(s):
Piyong Yu, Pedro F. Silva and Antonio Nanni
Publication:
Symposium Paper
Volume:
327
Issue:
Appears on pages(s):
53.1-53.12
Keywords:
GFRP, grids, polyurea, reinforced concrete, retrofit, strengthening.
DOI:
10.14359/51713374
Date:
11/1/2018
Abstract:
Flexural strengthening of reinforced concrete (RC) beams with fiber reinforced polymer (FRP) composites and two different bonding agents were investigated in this research. The bonding agents used in this research consisted of an epoxy paste and a sprayed polyurea. When polyurea was used as the bonding agent, it was sprayed to specific regions on the RC beams. Three RC beams were flexural strengthened with FRP composites according to the following techniques: (a) sprayed polyurea with and without glass FRP (GFRP) grid reinforcement, and (b) manual layup using one GFRP grid. Experimental results clearly indicate that flexural strengthening with the un-reinforced or reinforced polyurea technique is an effective strengthening scheme. Advantages of using polyurea over other epoxy based methods are that the application process requires significantly less time and the polyurea cures within minutes. Furthermore, no debonding of the un-reinforced or reinforced polyurea system was observed, suggesting a further benefit of this technique. Application of the polyurea system and key experimental results are presented and discussed herein.
Related References:
ACI 400K (2005), Guide for the Design and Construction of externally Bonded FRP Systems for Strengthening Concrete Structures (ACI 440.2R-05), American Concrete Institute, Farmington Hill, Michigan.
ACI Committee 318 (2002), “Building Code Requirements for Structural Concrete (ACI 318-02) and Commentary (318R-02)”, American Concrete Institute, Farmington Hills, Michigan.
Agarwal, B.D., and Broutman, L.J. (1990), Analysis and Performance of Fiber Composites, John Wiley and Sons, New York, pp. 59-72.
Alkhrdaji, T., and Nanni, A. (2001), “Design, Construction, and Field-Testing of a Concrete Box Culvert Bridge Reinforced with Glass FRP Bars,” Non-Metallic Reinforcement for Concrete Structures FRPRCS-5, Cambridge, July 16th-18th, 2001, pp. 1055-1064.
Alkhrdaji, T., Nanni, A., Chen, G., and Barker, M. (1999), “Upgrading the Transportation Infrastructure: Solid RC Decks Strengthened with FRP,” Concrete International: Design and Construction, Vol. 21, No. 10, Oct., pp. 37-41.
American Concrete Institute, ACI, (2014), Guide to Concrete Repair, ACI 546R-14, Farmington Hills, Mich., 70 pp.
American Concrete Institute, ACI, (2017), Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures, ACI 440.2R-17, Farmington Hills, Mich., 116 pp.
Bakis, C.E., Bank, L.C., Brown, V.L., and Cosenza, E. (2002), “Fiber-Reinforced Polymer Composites for Construction—State-of-the-Art Review,” ASCE Journal of Composites for Construction, Vol. 6, No. 2, pp. 73-87
Cheng, F. (2001), Matrix Analysis of Structural Dynamics–Applications and Earthquake Engineering, Marcel Dekker, Inc., New York, NY, 997 pp.
Chris, G. (2000), Polyurea: a market overview, European Coatings Journal, October, pp. 54.
International Concrete Repair Institute, ICRI, (2013),—Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair, ICRI 310.2R-2013, St. Paul, Minnesota, 48 pp.,
Miller, B.D. (1999), Bond between Carbon Fiber Reinforced Polymer Sheets and Concrete, MS thesis, University of Missouri – Rolla, MO
Teng, J.G., Chen, J.F., Smith, S.T., and Lan, L. (2002), FRP-strengthened RC structures, New York: Wiley, pp 45-60.
Zeng, Y., Caspeele, R., and Taerwe, L. (2015), “Compressive membrane action in FRP-strengthened concrete beams,” Elegance in Structures IABSE Conference, Nara 2015, 5pp.