Rheology of viscous materials from the CNR-IGG Tectonic Modelling Laboratory at the University of Florence (Italy)

Abstract

This dataset provides rheometric data of three viscous materials used for centrifuge experiments at the Tectonic Modelling Laboratory of CNR-IGG at the Earth Sciences Department of the University of Florence (Italy). The first material, PP45, is a mixture of a silicone (Polydimethylsiloxane or PDMS SGM36) and plasticine (Giotto Pongo). The PDMS is produced by Dow Corning and its characteristics are described by e.g. Rudolf et al. 2016a,b). Giotto Pongo is produced by FILA (Italy). Both components are mixed following a weight ratio of 100:45, and the final mixture has a density of 1520 kg m3.

The second material, SCA705 is a mixture of Dow Corning 3179 putty, mixed with fine corundum sand and oleic acid with a weight ratio of 100:70:05 and a resulting density of 1660 kg m3. The final material, SCA7020 consists of the same components as SCA705, but with a slightly higher oleic acid content reflected in the weight ratio of 100:70:20. The mixture’s density is 1620 kg m3. The material samples have been analyzed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (20˚C). Rotational (controlled shear rate) tests with shear rates varying from 10-4 to 1 s-1 were performed. Additional temperature tests were run with shear rates between 10-2 to 10-1 s-1 for a temperature range between 15 and 30˚C.

According to our rheometric analysis, the materials all exhibit shear thinning behavior, with high power law exponents (n-number) for strain rates below 10-2s-1, while power law exponents are lower above that threshold.For PP45, the respective n-numbers are 4.8 and 2.6, for SCA705 6.7 and 1.5, and for SCA7020 9.1 and 2.0. The temperature tests show decreasing viscosities with increasing temperatures with rates of -3.8, -1.4 and -1.9% per ˚K for PP45, SCA705 and SCA7020, respectively. An application of the materials tested can be found in Zwaan et al. (2020).

Authors

• Zwaan, Frank;University of Florence, Florence, Italy;University of Bern, Bern, Switzerland
• Rudolf, Michael;GFZ German Research Centre for Geosciences, Potsdam, Germany
• Corti, Giacomo;CNR Italian National Research Council, Italy
• Keir, Derek;University of Southampton, Southampton, UK;University of Florence, Florence, Italy
• Sani, Federico;University of Florence, Florence, Italy

Contact

• Zwaan, Frank (Postdoc Researcher) ; University of Bern, Bern, Switzerland; ➦

Contributors

Tectonics Modelling Laboratory (IGG-CNR, Italy); HelTec - Helmholtz Laboratory for Tectonic Modelling (GFZ German Research Centre for Geosciences, Germany)

Keywords

EPOS, analogue models of geologic processes, multi-scale laboratories, property data of analogue modelling materials, European Plate Observing System, software tools, Force sensor, Temperature measurement, Plasticine, Sand > Corundum Sand, Silicon/Silly putty/PDMS, Python, Rheometer, Stress exponent, Viscosity, Force sensor, Plasticine, Python, Rheometer, Sand > Corundum Sand, Silicon/Silly putty/PDMS, Stress exponent, Temperature measurement, Viscosity