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Evaluation of the workability and rheology parameters of self-compacting concrete

ABSTRACT

The design of self-compacting concrete is complex, so it requires a thorough study of the mixture and their behavior in the fresh state. According to workability requirements required by the Brazilian standard NBR 15823-1, we decided to get workability parameters and rheology through studies in mortars, and later studies in concrete. The parameters resulting from the evaluation of the mortars were obtained by means of the following tests: mini-slump, mini funnel and rheological characterization using the rheometer of Rheotest N4.1 brand. The parameters resulting from the evaluation of concrete were obtained through the tests and mathematical models: slump flow, T500, V funnel, J ring, L box, U box, segregation tube, rheological parameters estimated by mathematical equations proposed by Sedran and De Larrard. From these parameters, it was possible to parameterize or map the self-compacting concrete according NBR 15823-1, and an assessment was made of the use of this classification standard for self-compacting concrete. It was found, for example, that the T500 test results showed no apparent consistent plastic viscosity compared to plastic apparent viscosity results obtained by testing funnel V. It was found that the bolt assays that evaluate the ability such, as box L and J ring, did not show a good match between their results, so may compromise the classification as self-compacting concrete. Finally, in general, an important relation of the workability parameters and rheology of mortars and concretes was observed and, in addition, it was awakened in order to better evaluate the workability of the concrete in the face of some inconsistencies in the results of some tests.

Keywords:
self compacting concrete; mortar; passing ability; passing ability and segregation resistance

Laboratório de Hidrogênio, Coppe - Universidade Federal do Rio de Janeiro, em cooperação com a Associação Brasileira do Hidrogênio, ABH2 Av. Moniz Aragão, 207, 21941-594, Rio de Janeiro, RJ, Brasil, Tel: +55 (21) 3938-8791 - Rio de Janeiro - RJ - Brazil
E-mail: revmateria@gmail.com