INTERFACIAL SHEAR BEHAVIOR OF COMPOSITE FLANGED CONCRETE BEAMS

Abstract

Composite concrete decks are commonly used in the construction of highway bridges due to their rapid constructability. The interfacial shear transfer between the top slab and the supporting beams is of great significance to the overall deck load carrying capacity and performance. Interfacial shear capacity is directly influenced by the distribution and the percentage of shear connectors. Previous research and design guidelines suggest the use of two different approaches to quantify the required interfacial shear strength, namely based on the maximum compressive forces in the flange at mid-span or the maximum shear flow at the supports. This study investigates the performance of flanged reinforced concrete composite beams with different shear connectors’ distribution and reinforcing ratios. Furthermore, the work tackles the performance of flanged reinforced concrete composite beams strengthened with two strengthening techniques against interfacial shear deficiency. The present study incorporated both experimental and analytical programs for simply supported RC beams. The experimental phase of the present study includes testing a group of composite RC T-beams with 2.10 m span under six point loading up to the appearance of the first crack between web and flange with different shear connectors’ ratio and distribution along the beam span. The tested beams were retested up to failure after strengthening using two different strengthening schemes either by using steel angles 60x5mm along the span of the beam connecting the web and the flange or by using steel angles and steel anchors with 6-mm diameter forming U-shape connecting the web and the flange.