Contribution to the rheological study of cementitious pastes with addition of residues from the processing of ornamental rocks

V Y Sato,A P L Galina,J E S L Teixeira

doi:10.1590/s1983-41952018000600007

V Y Sato, A P L Galina + Show 1 more

Open Access

https://doi.org/10.1590/s1983-41952018000600007

Copy DOI

Abstract

Abstract Brazil is one of the world's largest producers and exporters in the field of ornamental stones. On the other hand, the production and processing of ornamental stones result in a large volume of unused material in the form of sludge, usually discarded inappropriately in sedimentation ponds or landfills. Several researches have been carried out aiming the reuse of this material in cementitious matrixes. In the field of rheology, there are still incipient national studies that use the rheological parameters obtained experimentally to determine the behavior of cement matrix based on Portland cement. Thus, the objective of this work is to characterize rheologically the behavior of cementitious pastes with and without addition of ornamental rock processing residue (RBRO) in its natural condition. Cement pastes were prepared with three a/c ratios (0.45, 0.55, 0.65) and four residue addition contents (0%, 5%, 10%, 15%) and submitted to the flow test. In tests for characterization of the residue, the RBRO presented as a material of specific fineness and mass near the cement, having low reactive activity, indicating that the residue can be used as an inert mineral addition in the cementitious matrix. In the rheological characterization tests of the pulps studied, it was observed in the flow tests that the samples behaved as a non-Newtonian, pseudoplastic and thixotropic fluid.

Highlights

The preliminary questions of this research revolve around the characterization and use of the ornamental stone residue (OSR) generated during the production and processing of ornamental rocks, named by the State Institute of the Environment and Water Resources (IEMA) as sludge from the processing of ornamental rocks, as alternative material in the production of concrete
In tests for characterization of the residue, the resíduo do beneficiamento de rochas ornamentais (RBRO) presented as a material of specific fineness and mass near the cement, having low reactive activity, indicating that the residue can be used as an inert mineral addition in the cementitious matrix
The present work aims to use rheology concepts to investigate the influence of the incorporation of ornamental stone residues on the rheological properties of cement pastes, analyzing the interactions that occur between this waste and the other constituents of the pastes

Summary

Introduction

Some studies have pointed out the reuse of OSR as an alternative material in several areas and applications, such as mortar [3], ceramic coating [2], interlocking floor [4], among others Since much of this waste is recycled in the form of an industrial by-product, one way of contributing to the use of OSR is in concrete fabrication [5,6,7,8,9,10,11,12]. Through the Brazilian Association of Technical Standards (ABNT) we obtain the standard NBR 7212 [13], which determines the time limit to transport and pour concrete, which is 150 minutes between the start of mixing. The higher the yield stress of a cementitious matrix, the lower the slump obtained by the traditional slump test of Property

Objectives

Results

Conclusion