Influence of Soffit Bonded CFRP Strips on Shear Capacity and Failure Type of RC Beams without Stirrups
Presented herein is an experimental investigation on the efficacy of soffit-bonded longitudinal CFRP strips in upgrading the load-carrying capacities of RC beams without steel stirrups, a necessary disposal when the wrapped or the side transverse CFRP strips bonding is impossible due to the inaccessibility of the beam sides. The program deals with testing eight RC beams destitute of web reinforcement and strengthened by various CFRP strips combinations of soffit-bonded strips frequently accompanied by longitudinal top-bonded ones, in addition to three unstrengthened beams one of which is provided by the minimum amount of steel stirrups. The purpose is to evaluate their prime performances (shear resistance and concrete fracture mechanism with CFRP failure modes) and complementary properties (stiffness, ductility and energy absorbability). Effects of the fiber orientation in the CFRP strips and the shear span-to-depth ratio are specially attended. Test results demonstrate the profitable role of the flat soffit-bonded CFRP strips in delaying shear failure, admitting additional deflection and elevating the energy absorbability by 22 %. They also manifest the effective role of the longitudinal full-length top CFRP strips in contributing the resistance to shear failure announced by its transverse rupture. The advantageous effect of the two narrow side “crooks” along the soffit-bonded CFRP strips appears in the substantial increase in the energy absorbability and ultimate resistance attributed to magnifications in the concrete fracture pattern and CFRP debonding.
Norris, T., Saadatmanesh H., Ehsani M.R.,"Shear and Flexural Strengthening of R/C Beams with Carbon Fiber Sheets" Journal of Structural Engineering, Vol. 123, pp. 903-911, 1997.
Khalifa, A., Tumialan, G., Nanni, A., Belarbi, A., "Shear Strengthening of Continuous RC Beams Using Externally Bonded CFRP Sheets", American Concrete Institute, Proc. 1999, pp. 995-1008
Khalifa, A., Belarbi, A., Nanni, A., "Shear Performance of RC Members Strengthened with Externally Bonded FRP Wraps", Proceedings of Twelfth World Conference on Earthquake, 2000.
Li, A., Assih, J., Delmas, Y., "Shear Strengthening of RC Beams with Externally Bonded CFRP Sheets", Journal of Structural Engineering, Vol. 127, pp. 374-380, 2001.
Imam, M., Tahwia, Elagamy, Yousef, "Behavior of Reinforced Concrete Beams Strengthened With Carbon Fiber Strips", Mansoura Engineering Journal, Vol. 29, pp. 22-40, 2004.
Sim, J., Kim, G., Park, C., Ju, M., "Shear Strengthening Effects with Varying Types of FRP Materials and Strengthening Methods", International Symposium on Fiber-Reinforced Polymer, 2005.
Barros, J.A., Dias, S.J., Lima, J.L., "Efficacy of CFRP-Based Techniques for the Flexural and Shear Strengthening of Concrete Beams", Cement and Concrete Composites, Vol. 29, pp. 203-217, 2007.
Abdul-Muttalib I.S., Al-Modhafer, A.H., "Behavior of Concrete Beams Reinforced in Shear with Carbon Fiber Reinforced Polymer", Journal of Engineering, Vol. 17, pp. 46-61, Feb. 2011.
Yousif Z.M., "R.C. Beams Strengthening by Carbon Fiber Reinforced Polymer Against Two Points Load Divergence", Journal of Engineering and Development, Vol. 16, pp. 266-280, Jun. 2012.
Hawileh, R.A., Nawaz, W., Abdalla, J.A., Saqan, E.I., "Effect of Flexural CFRP Sheets on Shear Resistance of Reinforced Concrete Beams", Composite Structures, Vol. 122, pp. 468-476, 2014.
Nitereka, C. and K. Neale, "Analysis of Reinforced Concrete Beams Strengthened in Flexure with Composite Laminates", Canadian Journal of Civil Engineering, Vol. 26, pp. 646-654, 1999.
Kachlakev, D.I., "Finite Element Analysis and Model Validation of Shear Deficient Reinforced Concrete Beams Strengthened with GFRP Laminates", California Polytechnic State, 2002.
Hu, H.-T., Lin, F.M., Jan, Y.Y., "Nonlinear Finite Element Analysis of Reinforced Concrete Beams Strengthened by Fiber-Reinforced Plastics", Composite Structures, Vol. 63, pp. 271-281, 2004.
Al-Ta'ie, Y.M., "Nonlinear Finite Element Analysis of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer", M.Sc. Thesis, Al-Mustansiriya University, Iraq, 2006.
Farhan O.S., "Shear Behavior of RC Beams Strengthened with Carbon Fiber Polymers Using Finite Element Analysis", M.Sc. Thesis, AL- Nahrain University, Iraq, 2009.
Al-Jurmaa, M.A., "Non Linear Three Dimensional Finite Elements Analyses of Reinforced Concrete Beams Strengthened by CFRP", University of Mosul- College of Engineering, 2010, pp. 62-71.
Ibrahim, A., and Mahmood, M., "Investigations to the Parameters Effect Shear Strength of RC Beams Strengthened with CFRP Laminations", Modern Methods and Advances in Structural Engineering and Construction, pp. 21-26, Jun. 2011.
Jayalin, D., Arulraj, P.G., Karthika, V., "Analysis of Composite Beam Using ANSYS", College of Technology, Vol. 4, pp. 11-15, Aug. 2015.
ACI Committee 318, "Building Code Requirements for Structural Concrete (ACI 318M-14) and Commentary (ACI 318RM-14) ", American Concrete Institute, Farmington Hill, MI, 2014.
ACI Committee 440.2R, "Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures", 2008.
- There are currently no refbacks.