Tensile behaviour of cast-in-place headed anchors with different embedment depths

The equipment of French nuclear power plants is fixed on reinforced concrete structures with base plate with headed fasteners. Electricity of France decided to carry out an experimental research program in partnership with Laboratory of Civil and Environmental Engineering in order to optimise the design of the headed fasteners and identify safety margins. This article introduces the results of static tension tests on an anchorage composed of an anchor plate welded to four headed rods. The anchors are cast in place in a reinforced concrete block. The experimental campaign is carried out on anchors and anchor groups with reduced embedment depths. Tests on single headed rods are also carried out in order to analyse the group effects. The sliding of the anchor groups, the strain of the head rods, the strain of the stirrups and the surface concrete block displacements are measured. The collapse of the anchorages is caused by a failure of the steel rods or a concrete breakout failure for a loading ranging between 600 and 300 kN. The experimental ultimate strength is compared with ultimate load obtained from the technical specifications of Eurocode. This experimental campaign will provide a data base enabling the development of numerical models in order to improve the design.