Petrographic And Physico-Mechanical Studies On Granitic Rocks Around Bidadi, Ramanagaram Taluk, Karnataka State
The quality of dimension stones not only depends on aesthetic look and elegance, but also its petrographic
characteristics and mechanical properties. The systematic studies in the laboratory on unconfined compressive strength
(UCS) and unconfined tensile strength (UTS) are the key properties for characterization of rock materials in engineering
practices. The present study is on the determination of the quality of granite for its exploitation for dimension / ornamental
purposes by petrographic and strength studies.
The study area of the present investigation is a quarry site near Bidadi, Ramanagaram district. The petrography, index
properties, and mechanical properties were studied as per standard methods. Thin section studies reveal that granite has 30-
40% quartz, 45-65% feldspar and 5-8% accessories. Quartz is anhedral showing wavy extinction. Microcline are tabular and
exhibits typical cross hatched twinning. Biotite occurs as minute flakes and shows preferred orientation. Optically pleochoric
from yellowish brown to green. The results of UCS for all selected samples vary from 201- 218 MPa and were classified as
very high compressive strength material. Similarly TCS varies from 7.00-10.17 MPa.
Based on petrography and strength studies, the granite can be used not only as regular foundation stones, coarse aggregate,
and railway ballast but also as dimension stones and for civil engineering projects.
Keywords- Granite, petrography, index properties, UCS, TS, dimension stone.