Reologia do concreto com agregados reciclados

Abstract

Civil construction is a sector that grows exponentially worldwide and, consequently, it generates large quantities of construction residue that end up increasing the degradation of the environment. Therefore, it’s highly needed to find alternatives that control the reinless generation of said residues and decrease the impacts that are caused. Besides the environmental factor, it’s important to study concrete innovations, such as the self-compacting concrete, which aims to optimize concrete production, giving the concrete better flowability and better workability. The first step towards understanding the behavior of a fluid is by studying its rheology. The rheological study has great importance since it evaluates the flow and the viscosity of a mixture on its fresh state and it can also predict and understand the behavior of the mixture when in its hardened state. Thus, the present paper intents to study the rheological properties of a self-compacting concrete that uses, in its composition, 100% of recycled aggregates. In order to carry out the present paper two concretes were produced, one with only natural aggregates in its composition and another one with only recycled aggregates with the objective of evaluating and comparing its performances at both fresh and hardened states. The fresh concrete was evaluated by using slump flow, t500 time, L box and V funnel tests; the hardened concrete was evaluated by the compressive strength test. For the rheological study, it was made use of the equations proposed by Sedran and De Larrard to estimate the rheological parameters of the selfcompacting concrete. With the results of the tests, it was found that the presence of recycled aggregates in the concrete decreased the plastic viscosity and brought up a loss of workability in the mixture, in addition to not reaching the self-compacting criteria. The recycled aggregates also significantly decreased the compressive strength of. Concrete.