Due to their general robust behaviour and high reliability, embedded parts (EPs) as a group of headed studs welded to an anchor plate cast in concrete are heavily used in nuclear power plants. Frequently, the EPs consist of headed studs arranged in more than one anchor row. Typically, the concrete slabs in which the EPs are cast have significant amount of reinforcement. The behaviour of such anchor groups under shear, loaded perpendicular to an edge, in reinforced concrete is not well-researched to date. In this work, an optimum experimental program is carried out on anchor groups in unreinforced and reinforced concrete loaded in shear perpendicular to the edge. Anchor groups with up to four anchor rows perpendicular to the edge are tested in concrete with four different levels of shear reinforcement. A significant influence of shear reinforcement on failure loads of anchor groups was observed. The high conservatism in the approach according to draft EN 1992-4 to calculate the failure load of anchor groups under shear loading was clearly brought out. It was observed that in contrast to the current approach of assuming the failure crack at the front anchors, the real failure crack always starts from back row of anchors. Further, even a relatively small amount of reinforcement contributes to the failure load, however, beyond a certain point, adding further reinforcement does not increase the ultimate load. In these applications the peak load is limited by failure of compression strut. Both of these aspects are ignored in current model.
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