Pullout Behavior of Anchored Steel Bars and Grouted Headed Bars

Abstract

This paper aims to study the tensile behavior of several types of anchored steel bars used in the cast-in-place connections considering the bonding condition between steel bars and concrete and in the precast concrete connections based on the bond behavior of the headed steel bars grouted in ducts. The pullout tested bars have been experimentally conducted using a static tensile loading in order to evaluate the pullout behavior, the failure mode, and the required development length. Nine pullout tests have been conducted for the cast-in-place straight and 90-degree hooked steel bars, and the grouted headed bars. In addition, a comparison of the calculated development length has been introduced considering different building codes. Results have showed that the peak pullout load has been observed in the cast-in-place 90-degree hooked end bars. Furthermore, the pullout load and the required development length of the cast-in-place straight end and the grouted headed bars have been similar, and they have been higher than 97% of the cast-in-place 90-degree hooked end bar. For the grouted-headed bars and the cast-in-place 90-degree hooked, ACI 318-19 and ECP 203-2020 have showed more rational results compared to experiments while it has been very conservative for cast-in-place straight end bars.