Weathering has several effects on the physical, strength and material behaviour characteristics of rocks. Various researchers have attempted to obtain weathering classifications using qualitative and/or quantitative approaches. In this study, material behaviour under uniaxial loading conditions, mechanical and physical properties are investigated for reliable estimation of weathering degree of granodiorites. For this purpose, representative rock samples with different degrees of weathering from Havran (Balikesir/Turkey) were collected and the necessary investigations and tests were performed. Weathering grades ranging from unweathered (W0) to highly weathered rock (W3) were used for classification purposes. Core samples were tested in the laboratory to determine various physical and mechanical properties for each weathering class. Also, mineralogical properties of granodiorites were investigated and described for each weathering degree. Test results were used for analyzing and constructing prediction models with the aim of indirect determination of the weathering degree of granodiorites. Finally, a monogram was proposed to distinguish different weathering degrees under uniaxial loading conditions for rock engineering purposes.
Rocks, being conformed to technical specifications, are generally used as aggregates (cement aggregates, ballast aggregates etc.), filling materials (road embankment, joint filling material etc.), cover slab, brick and stone wall joints aimed to decoratively purposes in industry. Thus it is expected to increase production quality with detailed geological and geotechnical studies. A clear understanding of the weathering degree of rocks provides a great convenience in engineering applications.
Various researchers have attempted to obtain weathering classifications using qualitative and/or quantitative approaches. Qualitative classification schemes are based on field observations and some simple index properties. Quantitative classification schemes are tightly coupled with mineralogical and physico-mechanical properties, strength and defor-mability characteristics of rocks.
The progressive weathering in rocks lowers directly the quality of the rock materials and masses (Noble 1977, Fookes et al. 1988, Oyama et. al 1998, Yohta 1999, Wyllie 1999, Topal 2002, Arikan et. al. 2007, Marques et al. 2010).