Proceedings of CICE 2012 6th International Conference on FRP Composites in Civil Engineering - Rome, Italy, 13-15 June 2012
An experimental investigation of the cyclic response of hollow box bridge columns that comprise substandard construction details is presented. Two techniques were used to increase their insufficient shear strength: 1) wrapping with CFRP strips and 2) concrete jacketing. Relatively small amount of CFRP strips and concrete jacketing efficiently increased the shear strength. In both cases the ductility capacity was not substantially improved, since the minimum amount of jacketing was not able to prevent other unfavourable failure mechanisms induced by other substandard construction details. Particularly critical was buckling and rupture of the longitudinal bars as well as the bar slip at the column base. Different analytical methods were used to estimate the shear strength of as-built and strengthened columns. Based on the large differences between the methods it can be concluded that the problem of shear strength and deformability is, in general, not adequately solved. It may be appropriate to reconsider this problem in the future developments of the EC standards.
Keywords: CFRP jacketing; Cyclic response; experiment; hollow box bridge columns; RC jacketing; seismic response; shear strengthening
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