An Artificial Neural Network Model for Estimating the Shear Contribution of RC Beams Strengthened by Externally Bonded FRP

Document Type : Regular Paper


1 M.Sc. Student, Faculty of Civil Engineering, Semnan University, Semnan, Iran

2 Associate Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran

3 Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran


This paper provides an artificial neural network model for predicting the shear contribution of FRP in reinforced concrete (RC) beams strengthened in shear with externally bonded FRP. Although there are some models and equations for estimating the contribution of FRP, these models, in some cases, have a significant error in the calculation of FRP contribution. One of the reasons for these errors is neglecting the effect of shear span (a) to the effective depth of beam (d) ratio in FRP performance. In this model, mechanical and dimensional properties of RC beams strengthened and strengthening materials, and also the shear span to the effective depth of beam ratio (a/d) are taken as input parameters, and the shear contribution of FRP is the target of the network. After a comprehensive review in existing literature, 96 strengthened RC beams which all of them have FRP rupture failure mode were selected which 92 of them were used for training, validation and testing the network and four of them were used for controlling the generalization of the network. Finally, the outputs of the model have compared with ACI 440.2R, fib 14 and CIDAR guidelines, and the result indicated that the ANN model is more accurate than the existing guideline equations based on experimental result.


Main Subjects

[1] Täljsten, B., Strengthening concrete beams for shear with CFRP sheets, Construction and Building Materials, 2003, 17, 15–26.
[2] Triantafillou, T. C., COMPOSITES: A NEW POSSIBILITY FOR THE SHEAR STRENGTHENING OF CONCRETE, MASONRY AND WOOD, Composites Science and Technology 1998, 58, 1285-1295.
[3] Li, A., Diagana, C., Delmas. Y., CRFP contribution to shear capacity of strengthened RC beams, Engineering Structures 2001, 23, 1212–1220.
[4] Chen, J. F., Teng, J. G., Shear Capacity of Fiber-Reinforced Polymer-Strengthened Reinforced Concrete Beams: Fiber Reinforced Polymer Rupture, ASCE Structural Engineering. 2003, 129, 615-625.
[5] Berset, J. D., Strengthening of Reinforced Concrete Beams for Shear Using FRP Composites, M.Sc. thesis, Massachusetts Institute of Technology, Jan. 1992.
[6] Uji, K., Improving shear capacity of existing reinforced concrete members by applying carbon fiber sheets. Trans. Japan Concrete Institute, 1992, 14, 253-266.
[7] Vielhaber, J. and Limberger, E., Upgrading of Concrete Beams with a Local Lack of Shear Reinforcement, Federal Institute for Materials Research and Testing (BAM), Unpublished Report, Berlin, Germany, 1995.
[8] Chajes, M. J., Januska, T. F., Mertz, D. R., Thomson, T. A. and Finch, W. W., Shear strengthening of reinforced concrete beams using externally applied composite fab- rics. ACI Structural Journal, 1995, 92, 295-303.
[9] Sato, Y., Ueda, T., Kakuta, Y. and Tanaka, T., Shear reinforcing effect of carbon fiber sheet attached to side of reinforced concrete beams. In Advanced Composite Materials in Bridges and Structures, ed. M. M. El-Badry, 1996, 621-627.
[10] Gamino, A. L., Sousa, J. L. A. O., Manzoli, O. L., Bittencourt, T. N., Estruturas de Concreto Reforçadas com PRFC, Part II: Análise dos Modelos de Cisalhamento, Ibracon Structures and Materials Journal, 2010, 3, 24-49.
[11] Teng, J. G., Chen, G. M., Chen, J. F., Rosenboom, O. A., Lam, L., Behavior of RC Beams Shear Strengthened with Bonded or Unbonded FRP Wraps, Compos. Constr., 2009, 13, 394-404.
[12] Bousselham, A., Chaallal, O., Effect of transverse steel and shear span on the performance of RC beams strengthened in shear with CFRP, Composites: Part B 2006, 37, 37–46.
[13] Naderpour, H., Kheyroddin, A., Ghodrati Amiri, G., Prediction of FRP-confined compressive strength of concrete using artificial neural networks, Composite Structures, 2010, 92 (12), 2817-2829.
[14] ACI Committee 440 Report, Guide for the design and strengthening of externally bonded FRP systems for strengthening concrete structures. American Concrete Institute Committee; October 2001.
[15] Fib. Bulletin 14, externally bonded FRP reinforcement for RC structures. Technical report. Task Group 9.3 FRP (fibre reinforced polymer) reinforcement for concrete structures; 2001.
[16] CIDAR, Design guideline for RC structures retrofitted with FRP and metal plates: beams and slabs. Draft 3 – submitted to Standards Australia, The University of Adelaide; 2006.
[18] Triantafillou, TC., Shear strengthening of reinforced concrete beams using
[19] Epoxy-bonded FRP composites, ACI Struct. J 1998, 95, 107–15.
[20] Chaallal, O., Nollet, M.-J., and Perraton, D. 1998. “Strengthening of reinforced concrete beams with externally bonded fibre-reinforcedplastic plates: Design guidelines for shear and flexure.” Can. J. Civ. Eng., 25, 692–708.
[21] Christopher, K. Y., Leung, M., Mandy, Y. M., Herman, C. Y., Empirical Approach for Determining Ultimate FRP Strain in FRP-Strengthened Concrete Beams, composites for construction, 2006, 10, 125-138.
Volume 6, Issue 1 - Serial Number 11
February 2018
Pages 88-103
  • Receive Date: 28 January 2014
  • Revise Date: 08 May 2014
  • Accept Date: 08 June 2014
  • First Publish Date: 01 February 2018