Tension tests on cast-in-place inserts: The influence of reinforcement and prestress

Tension tests were conducted on four different types of cast-in-place inserts, including both wire-formed and bolt-type inserts, to investigate their behavior under conditions present in prestressed concrete bridge girders. The effects of parameters such as the level of axial compression, reinforcement details, limited edge distance, and interaction of double inserts on the behavior of the inserts were studied. Concrete breakout failures occurred in the majority of the specimens. Concrete breakout capacities measured for the unreinforced specimens corresponded closely to the breakout capacities predicted by ACI 318-05 equations for cracked concrete. Specimens with loop inserts exhibited stable and ductile behavior as a result of extensive plastic deformation of the insert. The other three types of inserts exhibited larger tensile load capacities than the loop inserts in the reinforced specimen. However, they did not have as much ductility. The behavior of the loop inserts was not significantly influenced by the test variables studied; the behavior of specimens with the other three types of inserts varied depending mainly on the reinforcement details.