Influence of the vertical grouting in the interface between corbel and beam in beam-to-column connections of precast concrete structures - An experimental analysis

The study of the connection between the elements in precast concrete structures is especially important since the performance of a structural system is directly related to such connections. In this context, an experimental study is presented to investigate structural behavior of a type of semi-rigid interior beam-to-column connection. The type of investigated connection is formed by a precast concrete beam supported on a precast concrete column corbel with the use of grout filling and bending continuity reinforcement bars crossing the column. The main purpose of this paper is to analyze the influence of vertical interface grout filling between the corbel and the beam on the behavior of this type of connection, when it is subjected to negative bending moment. Tests on four specimens were performed: two ones with vertical interface grout filling between the corbel and the beam and two ones without grout filling. The experimental results shown resistance adequate flexural strength capacity of the connections, which exhibited ultimate loads higher than the estimated by usual design of reinforced concrete sections. It was noticed that the vertical interface grout filling contributed to increase in rotational flexural stiffness and flexural strength capacity of the connections, around 5.05 times and 1.4 times, respectively, when compared to the connections without grout filling.