Estudo da incorporação de resíduos de scheelita no concreto autoadensável.

Abstract

With technological advances, special concretes have emerged, such as self-compacting concrete (SCC), characterized by filling forms without vibration. To provide the workability, fluidity and cohesion necessary for SCC, a superplasticizer additive and a large amount of fines are used in its composition. With this, several studies have been developed for the incorporation of residues that can be used in this function, or also as aggregates. In this work, scheelite residues were used, the fine one being used as an addition and the coarse one in place of the fine aggregate. A percentage of 20% of the fine was used in all the traces, because with its use an improvement in the properties of the fresh state was noticed. Thus, three traces were made, one of reference composed of: Portland cement CP II F, gravel 0, fine residue, sand, water and superplasticizer additive, and two others with the replacement of 50% and 25% of the sand by the coarse residue of the scheelite The concretes were evaluated in their fresh state through the tests: slump flow test, J ring, V funnel and L box, generating satisfactory results, except in the mix with 50% of residue for the L box test. the three mixes presented similar specific masses, different from the absorption and voids index, in which the concrete without coarse residue presented better results. However, these results did not influence the strength, since the traces in which the coarse residue was used showed higher values ​​for the compressive strength test performed after 7 and 28 days of curing. Thus, the incorporation of scheelite residues in self-compacting concrete is considered a good alternative for their reuse, since they presented favorable results in the fresh and hardened state, highlighting the good performance of TRS25 in the fresh state and of TRS50 in the fresh state. hardened.