A new test specimen to investigate the bond behavior of post-installed reinforcing bars

摘要

Recent developments in the field of adhesives have led to the availability of post-installed reinforcing bar (rebar) systems with high strength mortar. The bond strength of these mortar-rebar systems can reach significantly higher values than the bond strength of cast-in rebar systems in normal strength concrete. However, based on the boundary conditions of concrete cover, concrete strength, transverse reinforcement, etc., the usable bond strength of post-installed rebar system could be limited by concrete splitting prior to attainment of the bond strength. In order to study the influence of above-stated boundary conditions on the usable bond strength of post-installed rebar, a new test specimen is designed on the basis of the beam-end specimen. The specimen allows for testing of the post-installed rebar system under realistic boundary conditions and clearly defined bonded zone while measuring unloaded-end slip and the width of splitting cracks.