Análise da influência do uso de barra e fibras de aço no concreto submetido à tração

Abstract

This research aims is to study the change in conventional concrete behavior subjected to tensile when steel bars or fibers are added. For this purpose were tested specimens with the concrete matrix, concrete reinforced with steel bar with different diameters and different rate of steel fiber, and finally with concrete reinforcing by fiber and steel bar. The tests were realized in FDMS GR048 machine with a capacity of 200 kN and the test speed was 0.2 mm/s. Was obtained as a result of the tests an average strength of 1.57 MPa for the concrete matrix and 2.68, 6.04 and 6.59 MPa, for concrete reinforced with diameter bar of ɸ5 mm bar, ɸ8 mm and ɸ 10 mm, respectively. For the fiber reinforced concrete, there was a decrease in tensile strength with increasing fiber content, which was not expected. But it was not found a theoretical explanation for these results. It was concluded that the concrete reinforced with ɸ8 mm bar showed the best performance to tension, compared to reinforced concrete with others diameters of bar, to the case of the specimen under study. The strain, in the case of fiber reinforced concrete, was concentrated in only one crack, causing a decrease of the load less abruptly compared to other types of reinforcement.