Mechanical behavior analysis of concrete with recycled aggregate and addition of steel and AR glass fiber

ABSTRACT

The extensive use of concrete in the world causes the generation of large amounts of waste, linked to its production and use. At present, this waste is little used, however in some countries its use as a recycled aggregate is allowed in the production of new concrete. Studies indicate that the use of the recycled aggregate may reduce some mechanical characteristics of the concrete. In order to mitigate this problem, it is proposed the study of the behavior of this composite with fibers. The objective of this work was to analyze the mechanical behavior of concrete produced with recycled aggregate and steel and AR glass fibers. For the development of the research, two proportions of mixtures were executed, the reference with natural aggregate and the mixture with 30% of natural aggregate replacement by the recycled aggregate. From these, two mixtures were produced with percentages by volume addition of 0.25%, 0.38% and 0.50% of fiber, both of steel fiber and AR glass fiber, totaling 14 concretes. The axial compressive strength, tensile strength, modulus of elasticity, water absorption capacity and specific mass were determined. The results were analyzed with the aid of analysis of variance (ANOVA). With this, it was possible to verify that the compressive strength, at 28 days, tends to increase with the increase of the fiber content, mainly with the use of recycled aggregate. When the steel fiber content increases, there is an increase in the modulus of elasticity, and this behavior is not observed for the concrete with AR glass fiber. For absorption and specific mass tests, the type of aggregate does not significantly influence the behavior of the concretes of this research.

Keywords
Concrete; Recycled aggregate; Steel fiber; Glass fiber; Sustainability