Considerations on the design of indirect supports in reinforced concrete beams

Considerações sobre o projeto de apoios indiretos em vigas de concreto armado

abstract:

Indirect supports consist of beams being supported by others beams, demanding the presence of a hanger reinforcement, required by ABNT NBR 6118, that will act as a tie hanging the applied load from the supported beam to the upper chord of the supporting beam. Therefore, the present work, through the study of experimental results in the literature, aims to present recommendations for the design of indirect supports and hanger reinforcements in reinforced concrete beams. Through a parametric analysis, was obtained an equation that calculates the load to be suspended as a function of the dimensions of the beams. It was observed that in some cases the reinforcement can be dispensed. The hanger reinforcement must be added to the shear reinforcement and in the case of regions where there is a torsional moment acting on the support beam, it was noticed that only the inner legs of the support beam stirrups collaborate to hang the load.

Keywords:
indirect support; hanger reinforcement; design recommendations