Study on Strengthening of RC Beam Column Joint Using Hybrid FRP Composites
- 1 Department of Civil Engineering, SSM Institute of Engineering and Technology, Dindigul, India
- 2 Department of Civil Engineering, Thiagarajar College of Engineering, Madurai, India
- 3 Department of Civil Engineering, SSM Institute of Engineering and Technology, Dindigul, India
Abstract
Beam-Column joints are critical zones in reinforced concrete structures which are most vulnerable to earthquake forces. Hence strengthening beam-column joint is vital to save the structure and its inhabitants in case of seismic forces. Numerous retrofitting works using fibre reinforced polymer (FRP) composites are being undertaken worldwide. This work aims to investigate the effectiveness of strengthening beam-column joints using natural and artificial fibres. In this study, basalt (natural fibres) as monolithic composite (BFRP) and as hybrid composite along with glass (artificial fibres) were used for strengthening of beam-column joints. Totally six specimens were prepared and tested under monotonic loading. Specimen details used were: two control specimen, two specimens for monolithic wrapping and remaining two specimens for hybrid wrapping. The test results were compared with control and rehabilitated specimens. The performance of the treated joints was studied using the following parameters: initial and ultimate cracking loads, energy absorption, deflection ductility and stiffness at ultimate . From the test results, it was found that the hybrid combination of Basalt and Glass FRPs were found to be more effective in the treatment of beam-column joints. The strong column weak beam concept was achieved by failure in beam portion which helped in preventing the catastrophic failure of the entire structure.
- Robert Ravi, S. and Prince Arulraj, G. (2010) Experimental Investigation on the Behavior of R.C.C. Beam-Column Joints Retrofitted with GFRP-AFRP Hybrid Wrapping Subjected to Load Reversal. International Journal of Mechanics and Solids, 5, 61-69.
- El-Amoury, T. and Ghobarah, A. (2002) Seismic Rehabilitation of Beam-Column Joint Using GFRP Sheets. Engineering Structures, 24, 1397-1407. http://dx.doi.org/10.1016/S0141-0296(02)00081-0
- Tsonos, A.G. (2008) Effectiveness of CFRP-Jackets and RC-Jackets in Post-Earthquake and Pre-Earthquake Retrofitting of Beam-Column Sub Assemblages. Engineering Structures, 30, 777-793. http://dx.doi.org/10.1016/j.engstruct.2007.05.008
- Mahini, S.S. and Ronagh, H.R. (2010) Strength and Ductility of FRP Web-Bonded RC Beams for the Assessment of Retrofitted Beam-Column Joints of Retrofitted Beam-Column Joints. Composite Structures, 92, 1325-1332. http://dx.doi.org/10.1016/j.compstruct.2009.09.006
- Senthil Kumar, E. and Thirugnanam, G.S. (2010) Experimental Study on Behavior of Retrofitted with FRP Wrapped RC Beam Column Exterior Joints Subjected to Cyclic Loading. International Journal of Civil and Structural Engineering, 135-149.
- Balasubramanian, K., Lakshmanan, N., Antony Jeyasehar, C., Krishnamoorthy, T.S. and Bharatkumar, B.H. (2011) Experimental Investigations on FRP Retrofitted RC Beam-Column Specimens. Journal of Structural Engineering, 38, 405-416.
- Agarwal, P., Gupta, A. and Angadi, R.G. (2014) Effect of FRP Wrapping on Axial Behavior of Concrete and Cyclic Behaviour of External RC Beam Column Joints. KSCE Journal of Civil Engineering, 18, 566-573. http://dx.doi.org/10.1007/s12205-014-0259-y
- Ahmed Ghobarah, A.S. (2002) Shear Strengthening of Beam-Column Joints. Engineering Structures, 24, 881-888. http://dx.doi.org/10.1016/S0141-0296(02)00026-3
- Niroomandi, A., Maheri, A., Maheri, M.R. and Mahini, S.S. (2010) Seismic Performance of Ordinary RC Frames Retrofitted at Joints by FRP Sheets. Engineering Structures, 32, 2326-2336. http://dx.doi.org/10.1016/j.engstruct.2010.04.008
- Vijayalakshmi, N., Kalaivani, M., Murugesan, A. and Thirugnanam, G.S. (2010) Experimental Investigation of RC Beam Column Joint Strengthening by FRP Wrapping. International Journal of Civil and Structural Engineering, 1, 35- 49.