EXPERIMENTAL AND NUMERICAL ANALYSIS OF REINFORCED CONCRETE BEAM STRENGTHENED USING CARBON FIBER REINFORCED PLASTIC SHEETS AND BOLTED STEEL PLATE

Yıl 2018, Cilt: 36 Sayı: 1, 231 - 248, 01.03.2018

Emre Ercan Bengi Arısoy Aybike Özyüksel Çiftçioğlu

Öz

This paper presents experimental and numerical study on reinforced concrete (RC) beams with flexural strengthening by carbon fiber reinforced polymer (CFRP) sheets and steel plates. In the study, effect of strengthening on flexural of RC beams is examined. Also, the differences between CFRP sheet and steel plate retrofitting regarding flexural strength of the RC beams are indicated.
For experimental study, seven RC beams were produced. One of the beams is regarded as “control sample”, three of samples were strengthened using CFRP sheets and the other three samples strengthened using steel plates. Four points bending test was conducted, vertical displacements of the beams were measured. Tests results indicated that the beams were strengthened for flexure became vulnerable shear failure and CFRP application was better strength values in flexure than steel plates application. For numerical analysis, three-dimensional finite element modeling of strengthened and non-strengthened reinforced concrete beams is prepared. Reinforced concrete beam is modeled by using hexahedral, steel plate and CFRP sheets are modeled by using tetrahedral elements. Finite element analysis is performed by using ATENA non-linear analysis program. The results of experiments and finite element analysis are compared. Results indicated that the strengthened reinforced concrete beams have larger moment capacity, yet exhibit shear failure. Although, strengthened samples exhibit shear failure, failure is not brittle. Experimental results are also validated by finite element analysis.

Anahtar Kelimeler

Reinforced concrete beams, strengthening, carbon fiber polymers, steel plates

Kaynakça

• [1] Adhikary, B.B., Mutsuyoshi, H. and Sano, M. Shear strengthening of reinforced concrete beams using steel plates bonded on beam web: experiments and analysis, Construction and Building Materials, 2000;14:237-244.
• [2] Ali, M.S.M., Oehlers, D.J. and Park, S.M. Comparision between FRP and steel plating of reinforced concrete beams, Composites, Part A, 2001;32:1319-1328.
• [3] Baglin, P.S., Barnes, R.A., Mays, G.C. and Subedi, N.K. External steel plate systems for the shear strengthening of reinforced concrete beams, Engineering Structures, 2001;23:1162-1176.
• [4] Khalifa, A. and Nanni, A. Rehabilitation Of Rectangular Simply Supported RC Beams With Shear Deficiencies Using CFRP Composites, Construction and Building Materials, 2002;16:135-146.
• [5] Diagana, C., Li, A., Gedalia, B. and Dlemas, Y. Shear strengthening effectiveness with CFF strips, Engineering Structures, 2003;25:507-516.
• [6] Altin, S., Anil, O. and Kara M.E. Improving shear capacity of existing RC beams using external bonding of steel plates, Engineering Structures, 2005;27:781-791.
• [7] M. Maalej, K.S. Leong, Effect of beam size and FRP thickness on interfacial shear stress concentration and failure mode of FRP-strengthened beams, Compos. Sci. Technol. 65 (7–8) (2005) 1148–1158.
• [8] Barnes, R.C. and Mays, G.C. Strengthening of reinforced concrete beams in shear by the use of externally bonded steel plates: Part 1-Experimental programme, Construction and Building Materials, 2006;20:396-402.
• [9] Riyadh, A. and Riyah, A. "Coupled flexural – shear retrofitting of RC beams using CFRP straps", Composite Structures, 2006;75:457-464 pp.
• [10] H. Toutanji, L. Zhao, Y. Zhang, Flexural behavior of reinforced concrete beams externally strengthened with CFRP sheets bonded with an inorganic matrix, Eng. Struct. 2006; 28 (4) 557-566.
• [11] Arslan, G., Sevuk, F. and Ekiz, I. Steel plate contribution to load-carrying capacity of retrofitted RC beams, Construction and Building Materials, 2008;22:43-153.
• [12] Mitolidis G., Salonikios T., Kappos A. Test results and strength estimation of R/C beams strengthened against flexural or shear failure by the use of SRP and CFRP. Composites: Part B, 2012;43:1117-129.
• [13] Biscaia HC, Chastre C, Silva MAG. Double shear tests to evaluate the bond strength between GFRP/concrete elements. Compos Struct 2012;94(2): 681–94.
• [14] Yang Y, Sneed L, Saiidi MS, Belarbi A, Ehsani M, He R. Emergency repair of an RC bridge column with fractured bars using externally bonded prefabricated thin CFRP laminates and CFRP strip. Compos Struct 2015;133:727–38.
• [15] Zheng, Y.Z., Wang ,W.W., Brigham,J.C. Flexural behaviour of reinforced concrete beams strengthened with a composite reinforcement layer: BFRP grid and ECC, Construction and Building Materials, 2016;115:424-437.
• [16] ISIS Design Manual No.4: Strengthening reinforcing concrete structures with externally-bonded fiber reinforced polymers. Intelligent Sensing for Innovative Structures, Winnipeg, Canada, 2001.
• [17] ACI440.2R-02. Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures, Reported by ACI Committee 440, 2002.
• [18] Dong, Y. Zhao, M. Ansari, F. Failure Characteristics of Rein-forced Concrete Beams Repaired with CFRP Composites, in: Proceedings of the Third International Conference on Composites in Infrastructure (ICCI’02), June10–12, 2002, San Francisco, California, pp.51–65.
• [19] Ozyuksel, A. Flexural behavior of reinforced concrete beams strengthened by FRP sheets and steel plates, Master Thesis, Ege University, Department of Civil Engineering, Bornova, Izmir, 2012.
• [20] ATENA v5 nonlinear analysis software documentation, Cervenka Consulting, Prague, Czech Republic.
• [21] F. Buyle-Bodin, E. David, E. Ragneau, Finite element model- ling of flexural behaviour of exernally bonded CFRP rein- forced concrete structures, Engineering Structures 24 (2002) 1423–1429.
• [22] Q.S. Yang, X.R. Peng, A.K.H. Kwan, Finite element analysis of interfacial stresses in FRP-RC hybrid beams Mechanics Research Communications 31, Elsevier Science Ltd., 2004 331–340.
• [23] Aykac, S., Kalkan,I., Aykac, B., Karahan, S., Kayar, S. Strengthening and Repair of Reinforced Concrete Beams Using External Steel Plates, J. Struct. Eng., 2013, 139(6): 929-939.