Tensile strength of the grout-filled head-splice-sleeve

• A new type of splice sleeve to connect bars, head-splice sleeve (HSS) is proposed.
• Tensile test result of HSS presents that the HSS has enough tensile strength to deliver stress of bars.
• A proper design process for HSS is proposed on the base of test result.

This paper presents an experimental result to identify the bond behavior of head-splice-sleeve (HSS) with the consideration of several design factors as variables. In addition, it attempts to investigate strength evaluation method in consideration of the bearing effect caused by head attached to the bar and the bond strength between the embedded bar and grout mortar.As a result, the HSS specimen without head underwent a brittle mortar failure before yielding while the HSS specimens with suitable head size showed sufficient ductile behavior and rebar failure at the end. It was contributed to the bearing action of the head inside sleeve. From the analysis on the effect of head size, it was recommended that a suitable diameter ratio between head and bar is 1.3 for the design purpose. In addition, a proper design process was proposed for the HSS based on the test result and it was found that the ratio of test result and calculation result obtained by the equation ranged from 0.99 to 1.10 and the average ratio was 1.01. From this, it can be said that the strength of HSS with standard head size is suitably predicted by using the proposed equation.