Young's modulus of railway ballast stones measured via nano-indentation

This data set contains measurements of the Young’s modulus of railway ballast stones.
Two types of railway ballast were tested: “Calcite” (stems from Croatia) and “Kieselkalk”,
also known as Helvetic Siliceous Limestone, (stems from Switzerland).
It is planned to publish a journal paper, where more details on the tested ballast and evaluations of the test results will be presented.
This dataset’s metadata will be updated to include the paper’s citation details.

For each type of ballast, the Young’s modulus was measured on three separate stones via nano-indentation.
The machine used was the Hysitron TI Premier. Rock samples were ground and polished before 40 indentations were made into each sample. For the indentations, the following load function was used: 5 seconds of ramping up to 10,000 µN (1000 µN for the first pair of rock samples), 5 second dwell time, then 5 second force unloading. The outputted force-displacement curve was then analysed according to the Oliver-Pharr Method, [1], which involved the calculation of a reduced modulus and an assumption that v=0.3 to calculate the Young’s modulus.

The data set contains the following files:
C1.csv: measurements stone 1 for Calcite ballast (35 measurement points)
C2.csv: measurements stone 2 for Calcite ballast (31 measurement points)
C3.csv: measurements stone 3 for Calcite ballast (33 measurement points)
KK1.csv: measurements stone 1 for Kieselkalk ballast (20 measurement points)
KK2.csv: measurements stone 2 for Kieselkalk ballast (25 measurement points)
KK3.csv: measurements stone 3 for Kieselkalk ballast (17 measurement points)

Check the README.txt file for detailed information on the file content and technical aspects.

Note that for the same types of railway ballast several types of measurements are openly available:
[2]: friction coefficient in stone-stone contact
[3]: shape analysis based on 3D scans
[4]: uniaxial compression test and direct shear test

References:
[1]: Oliver, W., Pharr, G.: An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. Journal of Materials Research 7(6), 1564–1583 (1992). DOI 10.1557/JMR.1992.1564
[2]: Suhr, B., Butcher, T.A., Lewis, R., Six, K.: Cyclic friction tests of ballast stones interfaces under varying vertical load. Zenodo (2020). DOI http://doi.org/10.5281/zenodo.3893842. www.zenodo.org
[3]: Suhr, B., Six, K., Skipper, W., Lewis, R.: 3d scans of two types of railway ballast including shape analysis information. Zenodo (2020). DOI http://doi.org/10.5281/zenodo.3689592. www.zenodo.org
[4]: Suhr, B., Six, K.: Compression tests and direct shear test of two types of railway ballast [data set]. Zenodo (2018). DOI http://doi.org/10.5281/zenodo.1423742. www.zenodo.org