Influence of Geological Characteristics on Mechanical Properties of Crushed Stone Aggregates Produced from Meta-Volcanic Rocks in Finland

Abstract

We have tested mechanical properties of crushed stone aggregates produced from meta-volcanic rocks in Finland, and compared the test results to their geological characteristics. The study indicates that although mineral composition is generally a key parameter, textural features, especially the mineral fabric and grain-size distribution play sometimes even more important roles. For this work, we selected a total of nine samples, with three representatives for felsic, intermediate, and mafic meta-volcanic rocks. The selection was carried out so that the samples within each rock-type show enough textural variations for qualitative comparison between the geological characteristics and mechanical properties. The results emphasize, in an order of increasing importance, the roles of (1) textural features, (2) grain-size distribution, and (3) mineral composition. As only meta-volcanic rocks were tested, however, more data are needed to extrapolate the results to other lithologies like plutonic or sedimentary rocks. As a general outcome, the study underlines the importance of geological material knowledge, when selecting aggregates for different construction purposes, since the mechanical tests do not unambiguously describe the quality of any single rock type.