On the intrinsic behaviour of decomposed volcanic rocks

Abstract

The intrinsic behaviour of soils is very essential and the mechanical behaviour of reconstituted soils depends mainly on its intrinsic properties. The separate role played by particle shape, particle mineralogy and grading on the mechanical behaviour of soils resulting from weathered igneous rocks have not been extensively studied. The effects of particle shape, particle mineralogy and grading on the mechanics of decomposed volcanics have been systematically investigated through one-dimensional compression and triaxial tests. This was achieved by using samples of different weathering degrees. The results indicate that the influence of particle mineralogy on the one-dimensional compression behaviour is relatively small compared to grading. There is effect of grading on the shearing behaviour, and it is less pronounced than in compression. There is slight effect of grading at a small strain level. Generally, grading has a notable influence on the mechanical behaviour of volcanic saprolites, and it is more important than particle mineralogy for volcanic saprolites.