Petrographic analysis, rock material
A petrographic analysis provides a basis for evaluating the technical quality of a rock material.
VTI offers an analysis which involves:
- quantitative determination of the mineral contents, including the mica content.
Other parameters examined are:
- grain size
- metamorphic alterations
- weathering
- microfractures
- foliation.
Ordinarily, the investigation involves both a general appraisal and a more detailed thin-section examination of the material under a polarization microscope.
We comply with existing standards, such as:
- EN 932-3 – Test for general properties of aggregaes – Part 3: Procedure and terminology for simplified petrographic description
- EN 134 50 Aggregates for railway ballast and Swedish railway standard BVS 585.52
- RILEM recommended test method AAR-1 Detection of potential alkali-reactivity of aggregates – petrographic method (prepared by Sims and Nixon), Material and Structures, Vol. 36, 2003, pp. 480–496.
We can also carry out customized testing, such as determination of grain shapes with the aid of image analysis.
Our clients are primarily producers of rock materials and aggregate, contractors, and purchasers in the area of roads and infrastructure. Often they send materials to VTI for quality analysis, for example in connection with road and infrastructure construction. Other purposes may be ballast certification, damage investigations or disputes between parties.