Abstract
The use of externally bonded Fiber Reinforced Polymer (FRP) composites as a means of upgrading the flexural capacity of Reinforced Concrete (RC) one-way slabs is experimentally and numerically investigated in this study. A total of four groups of eight slabs were tested under four-point bending. The two slabs of the first group were left unstrengthened to be used as control specimens. The two slabs of the second group were externally strengthened with adhesively bonded pultruded, pre-cured CFRP plates. The four slabs of the last two groups were externally upgraded with unidirectional carbon (or E-glass) fiber fabric impregnated with an epoxy resin. In addition to the experimental program, a numerical investigation utilizing nonlinear Finite Element (FE) analysis was conducted using LS-DYNA software. Besides the eight slabs tested in this study, another eleven slabs were collected from the literature for the purpose of finite element validation. A comparison was made between the experimental and numerical results and good agreement was achieved. Based on FE validation, the numerical analysis was extended to include additional cases to study the effect of axial FRP stiffness and FRP-to-concrete width ratio on the flexural performance of upgraded slabs. As a result of the numerical study, new stiffness and reinforcement parameters were introduced in this research. These parameters were employed in the development of two new formulas for predicting the FRP debonding strain and percent gain in flexural capacity of FRP-strengthened slabs.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
ACI Committee 318 (2011). Building code requirements for structural concrete and commentary, ACI 318-11, American Concrete Institute, Detroit, MI, USA.
ACI Committee 440 (2008). Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures, ACI 440.2R-08, American Concrete Institute, Detroit, MI, USA.
Al-Rousan, R., Issa, M., and Shabila, H. (2012). “Performance of reinforced concrete slabs strengthened with different types and configurations of CFRP.” Composites: Part B, Vol. 43, pp. 510–521, DOI: 10.1016/j.compositesb.2011.08.050.
Aprile, A. and Feo, L. (2007). “Concrete cover rip-off of R/C beams strengthened with FRP composites.” Compos. Part B: Eng, Vol. 38, Nos. 5–6, pp. 759–771, DOI: 10.1016/j.compositesb.2006.07.015.
Arduini, M., Di Tommaso, A., and Nanni, A. (1997). “Brittle failure in FRP plate and sheet bonded beams.” ACI Struct. J., Vol. 94, No. 4, pp. 363–370.
Arduini, M., Nanni, A., and Romagnolo, M. (2004). “Performance of one-way reinforced concrete slabs with externally bonded fiberreinforced polymer strengthening.” ACI Struct. J., Vol. 101, No. 2, pp. 193–201.
Belytschko, T. B. and Tsay, C. S. (1981). “Explicit algorithms for nonlinear dynamics of shells.” Journal of Applied Mechanics, Applied Mechanics Division, ASME, Vol. 48, pp. 209–231.
Buyukozturk, O. and Hearing, B. (1998). “Failure behavior of precracked concrete beams retrofitted with FRP.” J. Compos. Constr., ASCE, Vol. 2, No. 3, pp. 138–144, DOI: 10.1061/(ASCE)1090-0268(1998)2:3(138).
Chang, F. K. and Chang, K. Y. (1987). “A progressive damage model for laminated composites containing stress concentration.” J. Composite Materials, Vol. 21, pp. 834–855, DOI: 10.1177/0021998387021.0904.
Chen, G. M., Chen, J. F., and Teng, J. G. (2012). “On the finite element modelling of RC beams shear strengthened with FRP.” Constr. & Build. Mater., Vol. 32, pp. 13–26, DOI: 10.1016/j.conbuildmat.2010.11.101.
Chen, J. F. and Teng, J. G. (2001). “Anchorage strength models for FRP and steel plates bonded to concrete.” J. of Struc. Eng., ASCE, Vol. 127, No. 7, pp. 784–791, DOI: 10.1061/(ASCE)0733-9445(2001)127:7(784).
Elsanadedy, H. M, Almusallam, T. H., Alsayed, S. H., and Al-Salloum, Y. A. (2013). “Flexural strengthening of RC beams using textile reinforced mortar — Experimental and numerical study.” Compos. Struct., Vol. 97, pp. 40–55, DOI: 10.1016/j.compstruct.2012.09.053.
Elsayed, W., Ebead, U. A., and Neale, K. W. (2007). “Interfacial behavior and debonding failures in FRP-strengthened concrete slabs.” J. Compos. Constr., ASCE, Vol. 11, No. 6, pp. 619–628, DOI: 10.1061/(ASCE)1090-0268(2007)11:6(619).
Erki, M. A. and Heffernan, P. J. (1995). “Reinforced concrete slabs externally strengthened with fiber-reinforced plastic materials.” Proc. of the 2nd Int. RILEM Symposium FRPRCS-2, pp. 509–516.
Hu, H-T., Lin, F-M., and Jan, Y-Y. (2004). “Nonlinear finite element analysis of reinforced concrete beams strengthened by fibre-reinforced plastics.” Compos. Struct., Vol. 63, Nos. 3–4, pp. 271–281, DOI: 10.1016/S0263-8223(03)0.0174-0.
Issa, M. I., Islam, M. S., Lesile, M., Abdulla, H., and Valle, C. D. (2000). “Seismic retrofit of reinforced concrete members with CFRP composites.” Proc. of the 2nd Conf. on Seismic Repair and Rehabilitation of Structures (SRRS2), pp. 3–81.
Issa, M. I., Shabila, H., and Issa, M. A. (2003). “Structural behavior of reinforced concrete beams strengthened with CFRP subjected to static and fatigue loading.” Proc. of the Structural Faults and Repair Conference, UK, 15p.
Kim, Y. J., Wight, R. G., and Green, M. F. (2008). “Flexural strengthening of RC beams with prestressed CFRP sheets: Using non-metallic anchor systems.” J. Compos. Constr., ASCE, Vol. 12, No. 1, pp. 44–52, DOI: 10.1061/(ASCE)1090-0268(2008)12:1(44).
Lesmana, C. and Hu, H-T. (2014). “Parametric analyses of square reinforced concrete slabs strengthened by fiber-reinforced plastics.” Constr. & Build. Mater., Vol. 53, pp. 294–304, DOI: 10.1016/j.conbuildmat.2013.11.083.
Livermore Software Technology Corporation (LSTC) (2007). LS-DYNA user’s keyword manual (nonlinear dynamic analysis of structures in three dimensions): Volume 1, Version 971, LSTC, Livermore, California, USA.
Lu, X. Z., Teng, J. G., Ye, L. P., and Jiang, J. J. (2005). “Bond-slip models for sheets/plates bonded to concrete.” Eng. Struc., Vol. 27, No. 6, pp. 920–937, DOI: 10.1016/j.engstruct.2005.01.014.
Lu, X. Z., Teng, J. G., Ye, L. P., and Jiang, J. J. (2007). “Intermediate crack debonding in FRP-strengthened RC beams: FE analysis and strength model.” J. Compos. Constr., ASCE, Vol. 11, pp. 161–174, DOI: 10.1061/(ASCE)1090-0268(2007)11:2(161).
Lundquist, J., Nordin, H., Täljsten, B., and Olafsson, T. (2005). “Numerical analysis of concrete beams strengthened with CFRP — A study of anchorage lengths.” In: FRP in Construction, Proc. of the Int. Symp. of Bond Behaviour of FRP in Structures, pp. 247–254.
Mazzotti, C., Savoia, M., and Ferracuti, B. (2008). “An experimental study on delamination of FRP plates bonded to concrete.” Constr. & Build. Mater., Vol. 22, pp. 1409–1421, DOI: 10.1016/j.conbuildmat.2007.04.009.
Meier, U. (1992). “Carbon fiber-reinforced polymers: Modern materials in bridge engineering.” Struct. Eng. Int., Vol. 92, No. 1, pp. 7–12, DOI: 10.2749/1016866927806.7020.
Meier, U. (1995). “Strengthening of structures using carbon fibre/epoxy composites.” Constr. & Build. Mater., Vol. 9, No. 6, pp. 341–351, DOI: 10.1016/0950-0618(95)00071.2.
Mosallam, A. S. and Mosalam, K. M. (2003). “Strengthening of twoway concrete slabs with FRP composite laminates.” Constr. & Build. Mater., Vol. 17, pp. 43–54, DOI: 10.1016/S0950-0618(02)00092.2.
Murray, Y. D. (2007). User’s manual for LS-DYNA concrete material model 159, Report No. FHWA-HRT-05-062, US Department of Transportation, Federal Highway Administration National Transportation Systems Center, USA.
Murray, Y. D., Abu-Odeh, A., and Bligh, R. (2007). Evaluation of concrete material model 159, Report No. FHWA-HRT-05-063, US Department of Transportation, Federal Highway Administration National Transportation Systems Center, USA.
Norris, T., Saadatmanesh, H., and Ehsani, M. R. (1997). “Shear and flexural strengthening of R/C beams with carbon fiber sheets.” J. Struct. Eng., ASCE, Vol. 123, No. 7, pp. 903–11, DOI: 10.1061/(ASCE)0733-9445(1997)123:7(903).
Obaidat, Y. T., Heyden, S., and Dahlblom, O. (2010). “The effect of CFRP and CFRP/concrete interface models when modeling retrofitted RC beams with FEM.” Compos. Struct., Vol. 92, pp. 1391–1398, DOI: 10.1016/j.compstruct.2009.11.008.
Oehlers, D. J., Park, S. M., and Ali, M. S. M. (2003). “A structural engineering approach to adhesive bonding longitudinal plates to RC beams and slabs.” Composites Part A, Vol. 34, pp. 887–897, DOI: 10.1016/S1359-835X(03)00153.2.
Santhakumar, R., Chandrasekaran, E., and Dhanaraj, R. (2004). “Analysis of retrofitted reinforced concrete shear beams using carbon fibre composite.” Electron. J. Struct. Eng., Vol. 4, pp. 66–74.
Sebastian, W. M. (2001). “Significance of midspan debonding failure in FRP-plated concrete beams.” J. Struct. Eng., ASCE, Vol. 127, No. 7, pp. 792–798, DOI: 10.1061/(ASCE)0733-9445(2001)127:7(792).
Seim, W., Horman, M., Karbhari, V., and Seible, F. (2001). “External FRP poststrengthening of scaled concrete slabs.” J. Compos. Constr., ASCE, Vol. 5, pp. 67–75, DOI: 10.1061/(ASCE)1090-0268(2001)5:2(67).
Shahway, M., Beitelman, T., Arockiasamy, M., and Sowrirajan, R. (2001). “Flexural strengthening with carbon fiber-reinforced polymer composites of preloaded full-scale girders.” ACI Struct. J., Vol. 98, No. 5, pp. 735–742.
Smith, S.T. and Teng, J.G. (2001). “Interfacial stresses in plate beams.” Eng. Struct., Vol. 23, No. 7, pp. 857–571, DOI: 10.1016/S0141-0296(00)00090.0.
Smith, S. T., Hu, S., Kim, S. J., and Seracino, R. (2011). “FRP-strengthened RC slabs anchored with FRP anchors.” Eng. Struct., Vol. 33, No. 4, pp. 1075–1087, DOI: 10.1016/j.engstruct.2010.11.018.
Tan, K. Y. (2003). Evaluation of externally bonded CFRP systems for the strengthening of RC slabs, MSc Thesis, University of Missouri-Rolla, 141p.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Elsanadedy, H.M., Almusallam, T.H., Alsayed, S.H. et al. Experimental and FE study on RC one-way slabs upgraded with FRP composites. KSCE J Civ Eng 19, 1024–1040 (2015). https://doi.org/10.1007/s12205-013-0689-y
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12205-013-0689-y