Estudo de propriedades reológicas e físico-mecânicas de concreto autoadensável com adição de resíduo de vermiculita.

Abstract

With the advancement of research in the field of concrete technology, self-compacting concrete appeared, a material capable of molding itself into forms without the need for vibration. The large amount of fines and the use of superplasticizer additive in its composition, provides greater workability, fluidity and stability to its fresh state. Several researchers seek to incorporate fine waste into the composition of the SCC, with the aim of improving its main properties, as well as providing greater sustainability. Paraíba is the second largest producer of vermiculite in Brazil and the processing of this mineral generates large volumes of fine waste that has no use, causing environmental damage that can be irreversible. Therefore, it was decided to study the rheological, physical and mechanical properties of SCCs with the incorporation of vermiculite residue. For this, a reference trace (without the residue) was dosed, whose composition was Portland Cement CP II F as a binder, fine and medium sand as fine aggregate, the coarse aggregate was gravel 0 and the superplasticizer additive was supplied by the company Sika Brazil. After measuring the reference trace, 3 traces were produced with partial replacement of fine sand for vermiculite residue in ratios of 10%, 15% and 20%. In general, in the fresh state, the traces with the incorporation of the residue showed a high capacity for resistance to segregation and excellent passing ability, considering that there was no flow block during the V funnel and L box tests. The concrete with the 20% ratio replacement showed a reduction in water absorption and the voids content in the order of 6.24% and 5%, respectively. There was a decrease in compressive strength, with the exception of the concrete with the 15% ratio replacement, which obtained a strength of 31.87 MPa, with the best results both in the hardened and the fresh states of the concrete. It is possible to conclude that the use of vermiculite residue allowed good results both in the fresh and hardened state of the concrete.