EVALUATION OF SOME MECHANICAL PROPERTIES OF GRANITES IN PARTS OF SOUTH-WEST NIGERIA

Abstract

This work provides an estimation of some engineering properties and behaviours of some rocks in parts of South-West Nigeria for use under various applications, planning and design of construction projects. In mining operations especially drilling and blasting, the brittle fracture of rock in-situ is a very good indicator for rock fragmentation and rock strength characterization. This work determined some strength characteristics and fracture behaviour of granite rocks in four different locations in Ondo and Ekiti States, Nigeria. Granite rocks were sampled, prepared and tested in the laboratory for the Uniaxial Compressive Strength (UCS) using 1100kN compression machine, Tensile Strength (TS) using Brazilian test and Point Load Strength Index (PLSI) using point load tester. Analysis on the strength characteristics of the selected rocks show that the UCS range from 110.65-173.76MPa, TS from 11.94 to 15.46 MPa and PLSI from 5.76 to 7.03MPa. From the result of the analysis, the rocks are classified as very high and high based on their UCS and PLSI respectively. The degree and nature of deformation of the rocks indicated brittle and intergranular fracture. It was found out that the plane of fracture is simple and its nature and description is axial splitting failure in uniaxial compression. The results also show that the strength parameters are positively correlated. The rock strength and behaviour database generated will serve as useful information to granite quarry operators and investors in quarry planning, equipment selection and organization.