Laboratory Investigation on Performance of Strengthening Techniques of RCC Beam

Mir Abdul Kuddus^1, and Izharul Haque Azad¹

¹Department of Civil Engineering, Khulna University of Engineering &Technology, Khulna-9203, Bangladesh

Cite this paper:
Mir Abdul Kuddus and Izharul Haque Azad. Laboratory Investigation on Performance of Strengthening Techniques of RCC Beam. American Journal of Civil Engineering and Architecture. 2017; 5(1):25-28. doi: 10.12691/ajcea-5-1-4

Abstract

Reinforced concrete members are the most abundantly used construction elements in civil engineering. These members are normally designed to sustain various types of loads. But due to several reasons the members experience much more load beyond their capacity. Inadequate attention during design and construction of new additional RCC story in our country has raised question about the performance of existing structures. RCC beam is such an important member which sometimes needs to be strengthened. There are various methods of strengthening that have been studied by the researchers such as section enlargement, use of additional bars, use of FRP and CFRP, use of ferrocement, steel plates, etc. This thesis work aims to study and compare the effect of three distinct strengthening techniques- providing additional steel bars from underneath with U shaped shear reinforcement, use of wire mesh and providing single layer of geo-textile with adhesive. The experimental results show that the percentage increase in ultimate load carrying capacity for the steel, wire mesh and geo-textile were found to be 51.96%, 26.5% and 14.5% respectively with respect to reference beams. The value of deflection at failure were 5.63mm, 6.18mm and 5.83 mm respectively while for reference beam the value was 5.33mm. The performance of geo-textile was very poor. The use of wire mesh provides greater value of deflection at failure compared to other two methods but the increase in load carrying capacity is about half of that for steel bar. The application of additional steel is labor intensive compared to other two methods but in terms of ultimate load, it overweighs the advantages compared to other two strengthening techniques.

Keywords:
strengthening repairing additional steel wire mesh geo-textile

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]	Angelo, D., Francesco F, “Flexural Strengthening of RC Beams with Cement-Based Composite”, 10.1061/(ASCE)CC.1943-5614.0000218, American Society of Civil Engineers, J. Compos. Constr., 15(5): 707-720, 2011.
[2]	An, W., Saadatmanesh, H., and Ehsani, M. R., “RC beams strengthened with FRP plates. II: Analysis and parametric study.” J. Struct. Engrg., ASCE, 117(11), 3434-3455, 1991.
[3]	Bansal, P. P., Kumar, M. & Kaushik, S., “Effect of wire mesh orientation on strength of beams retrofitted using ferrocement jackets”, International Journal of Engineering (IJE), Vol. 2, p. 8, 2008.
[4]	Diab Y.G.,. “Strengthening of RC Beams by Using Sprayed Concrete Experimental Approach.” Engineering Structures Vol. 20, pp. 631-643, 1998.
[5]	Kamran M. N., “Evaluation and repair methods to restore structural integrity of the reinforced concrete beams at Point Shilshole Condominium Building”, Washington, 2006.
[6]	Kothandaraman S., and Vasudevan G., “Flexural Retrofitting of RC Beams Using External Bars at Soffit Level - An Experimental Study.” Construction and Building Materials Vol. 24, pp. 2208-2216, 2010.
[7]	Mohamed H., Kunieda M., and Nakamura H., “Strength and Ductility of RC Beams Strengthened with Steel-reinforced Strain Hardening Cementitious Composites.”Cement & Concrete Composites Vol. 34, pp.1061-1066, 2012.
[8]	Ong, K., Paramasivam, P. & Lim, C., “Flexural strengthening of reinforced concrete beams using ferrocement laminates”, Journal of Ferrocement, Vol. 22, pp. 331-342, 1992.
[9]	Khan S.U., Rafeeqi S.F.A., and Ayub T., “Strengthening of RCC Beams In Flexure Using Ferrocement.” IJST, Transactions of Civil Engineering, Volume 37, 2013.
[10]	Zhang Y., “Repair and Strengthening of Reinforced Concrete Beams”, Honors Thesis, The Ohio State University, 2012.