Influence of edge proximity on concrete breakout failure in post-installed RC columns foundation joints

Abstract

This paper discusses findings from an experimental program aimed at investigation of concrete breakout failure within the rebar end anchorage zone of reinforced concrete column-to-foundation joints, with columns located in proximity of foundation edge/s. A total of four tests on full scale column foundation joints are presented. In all specimens the column main reinforcement is anchored in the foundation using post-installed rebar technology. All connections are designed with the objective to trigger concrete breakout failure mode within the rebar end anchorage zone. Finite element analyses were used as a tool to design the specimens. The paper presents discussion of the test results within the framework of expectations outlaid during design of the test specimens. The effects of bending compression from column on the concrete breakout capacity under influence of foundation edges is the specific focus of the present investigation. It is shown that the direction of application of load on the column largely determines the effect of bending compression from column on concrete breakout capacity. The test data presented in this paper offers the necessary benchmark data on concrete breakout behavior in the case of reinforced concrete column foundation joints under influence of foundation edges. This test data along with insights from finite element analyses is employed to explore and possibly identify necessary modifications to the current state-of-the-art consideration of concrete breakout capacity for reinforced concrete connections.