ANÁLISE EXPERIMENTAL E TEÓRICA EM VIGAS DE CONCRETO ARMADO COM FUROS NA ALMA

Abstract

Holes in beam are common in engineering works, for the passage of electrical, hydraulic pipes, among others. This study aims to verify if the presence of holes in different locations and quantities decreases the mechanical strength of reinforced concrete beams and to analyze the normative recommendations imposed by the Brazilian Standard of Design of Concrete Structures - NBR 6118 (2014). As it guides the same, the hole must be molded before concreting. It happens that in many cases the hole is drilled after the beam is made, having to be opened with the aid of drilling equipment, with the beam being vibrated at the time of drilling and still being able to cut the reinforcement, which may compromise the strength of the piece. For this study five beams were tested. Based on these tests, it was concluded that the presence of holes in different locations and quantities influences the mechanical strength and the breaking mode of beams. In addition, it could be seen that NBR 6118 (2014) is satisfactory for the design of holes in beams. However, the norm generalizes the conditions for all beam regions, making it conservative in relation to the distance between the hole faces and the sectioning of the reinforcement in pure flexion region.