PSI - Issue 64

Annalisa Napoli et al. / Procedia Structural Integrity 64 (2024) 975–982 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

981

7

110 125

EB plate - Rectangular section EB plate - T section MF plate

5 20 35 50 65 80 95

Bending moment increase [%]

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2

 r /  s

Fig. 6. Relationship between the relationship between the bending moment increase and the ration  r /  s .

3. Conclusions This paper presented a preliminary study on the flexural behavior of RC beams externally strengthened with steel plates. More specifically, a wide and comprehensive experimental database was compiled from the literature which, to the authors’ knowledge is the largest one ever collected. The database serves as a valuable tool for providing an overview of the experimental research available so far, including strengthening layouts, geometry of tested beams and exhibited failure mode. The typological analysis of the database was also useful for making preliminary considerations about the parameters that may affect the occurrence of premature failure of the beams due to debonding of the steel plate. Among these parameters, the ratio between the mechanical percentage of the external strengthening plate with respect to the mechanical percentage of the internal steel reinforcement (  r /  s ) plays a key role. Specifically, a higher ratio corresponds to a greater increase in bending moment for the strengthened members compared to the unstrengthened ones. However, an upper limit for this ratio should be established to prevent premature debonding failure of the steel plate. It is worth highlighting that the study presented here is the basis for a more in-depth theoretical investigation aimed at predicting the bending moment capacity of plated-strengthened beams. Also, this research activity is essential for formulating clear design indications for the flexural strengthening of RC beams with steel plates. More specifically, this research activity is fundamental to the formulation of clear design indications for the flexural strengthening of RC beams with steel plates, which is part of an ongoing research activities and will be reported in future publications. References Adhikary, B.B., Mutsuyoshi, H., 2002. Numerical simulation of steel-plate strengthened concrete beam by a nonlinear finite element method model. Construction and Building Materials 16, 291 – 301. Ajeel, A.E., Hashim Ghedan, R., Mukheef Hamza, D., 2011. Replacing of internal tension bars by external bonded plate. Journal of Engineering and Development 15(3), 90 – 103. Aykac, S., Kalkan, I., Aykac, B., Karahan, S., Kayars, S., 2013. Strengthening and repair of reinforced concrete beams using external steel plates. Journal of Structural Engineering 139(6), 929-939. Hussain, M., Sharif, A., Basunbul, I.A., Baluch, M.H., Al-Sulaimani, G.J., 1995. Flexural behavior of pre-cracked reinforced concrete beams strengthened externally by steel plates. ACI Structural Journal 92(1), 14 – 22. Jansze, W., 1997. Strengthening of reinforced concrete members in bending by externally bonded steel plates. PhD Thesis, Delft University of Technology, The Netherlands.