Shear behavior of shallow wide beams strengthened with externally bonded CFRP strips / Ahmed Aboulela Mostafa Mohamed ; Supervised Nayer A. Elesnawy , Hatem Mostafa Mohamed , Hatem Hamdy Geith

Thesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Civil Engineering

Shallow wide beams are frequently used as transfer elements where the total structural depth must be kept to a minimum. ECP 203-2007 has considered that beams to be shallow and wide if the depth is less than the largest of three values: 250 mm, 2.5 times the thickness of the flange, or half the width of the web. In this case, the nominal shear stress in shallow wide beams is less than the concrete shear strength, and ECP 203-2007 considers that the shear strength provided by concrete for shallow wide beams to be equal to 67% of the concrete shear strength for ordinary beams. This experimental program consists of twelve specimens. All specimens are 500 mm width, 170 mm thickness, and have a clear span between supports equal to 1300 mm. All beams have the same flexural reinforcement. The beams are divided into three groups. The first group contains two beams without vertical stirrups, and one of them is strengthened in shear with externally bonded CFRP strips. The second group contains six beams with the same volumetric ratios of vertical stirrups where five of them are strengthened with different ratios of CFRP strips. The third group contains four beams with the same volumetric ratio of vertical stirrups, which is higher than the beams in group two, where three of them are strengthened with different ratios of CFRP strips. The studied parameters are as follows: stirrups volumetric ratio, CFRP strips volumetric ratio, strip-width to strip-spacing for the same CFRP strips volumetric ratio, and the removing of strip with small anchorage length. This research aims to study simultaneously, the effect of vertical stirrups on the shear behavior of shallow wide beams, as well as shear behavior of shallow wide beams strengthened in shear with externally bonded CFRP strips

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