Estudo da aderência do concreto com fibras de aço utilizando o metacaulim.

Abstract

With the increasing development of the technology, it was possible to look for alternatives that could improve the properties of the materials. One of the most important properties for the characterization of the concrete is its compressive strength. In addition, the concrete stands out because of its properties, such as tensile strength in the weather and ease of molding. The adhesion between the concrete with fibers and bars of steel, in which the bars act increasing the load capacity of the concrete and the fibers in the control of the cracking. The adhesion is influenced by several factors such as: bar roughness, bar position during concreting, bar diameter, concrete strength, retraction, densification, porosity of concrete, etc. The present work aims at the analysis of the behavior of the adhesion between steel bars and fiberreinforced concrete together with metakaolin through the pushout test. In this research, prisms were used to evaluate the adhesion and CA50 ribbed steel bars with diameters of 8; 10; 12.5 and 16 mm, obeying the anchoring length of 5Ø. The concrete had addition of the metakaolin and the compressive strength of 40 MPa. The results of the adhesion stress presented by ABNT NBR 6118/2014 are much lower than the results presented in the experiments, showing that the standard is not confident about the calculated values. The use of metakaolin has benefits such as: it reduces the risk of corrosion of the reinforcement, reduces the total cost of maintenance to reconstruction in inverse proportion to the useful life, prevents the emergence of concrete pathologies, among others.