Reforço de consolos de concreto com protensão externa

Abstract

Changes in the use of buildings cause the load to be supported by the floors to be modified. This usually occurs due to the need to create deposits, installation of heavy machinery, cranes, etc. where the structures that receive loads higher than those which have been dimensioned, need to be reinforced. In prefabricated / pre-fabricated constructions the corbels are the elements responsible for receiving the loads coming from the slabs and beams, and transmit them to the pillars, thus characterizing regions of stress concentration. Thus, this work has as objective the study of the behavior of reinforced concrete corbels reinforced with prestressed external bars. For this, non-linear analyzes of consoles were performed through the ATENA software, and analytical checks of consoles through strut and tie models. The analyzes showed that the development of stresses on short consoles, externally or non-externally protruded, can be described by compression struts and ties. The cracking of the consoles was influenced by the protension. The comparison of the load capacity of the corbels with experimental results, resulted in differences between 2% and 24%. The analytical determination of the load capacity of consoles according to NBR 6118: 2014 presented divergent results in relation to the experimental results, demonstrating that the truss model and resistance parameters proposed by the standard lead to conservative results in favor of safety