The Effect of Mineral Composition, Microstructure on Physical Properties of Aggregate from River Punjkora and Kunai, Dir (Lower), Khyber Pakhtunkhwa, Pakistan

Abstract

Aggregate is a worldwide raw material used for various construction purposes which are obtained from geological material through drilling, blasting, mining, and river derived. This study has been focused on river Panjkora and Kunai-derived aggregates which are natural sources of aggregate used for various construction purposes in Dir (Lower). Field observation and detailed petrographic studies of representative samples reveal that rivers Panjkora and Kunai pass from different lithological units of granite, gabbroic, and amphibolite. Petrographically, the granitic rocks of the study area are consisting of alkali feldspar, quartz, and plagioclase feldspar. Minor accessory minerals in granite were hornblende, biotite, epidote, rutile, zircon, and ore minerals. The gabbroic rocks are consisting of pyroxene, plagioclase, and minor to accessory minerals including biotite, sphene, rutile, epidote, and ore minerals. The main mineral phases in amphibolites are hornblende, plagioclase, and a minor amount of quartz, sphene, and ore minerals. Gneissose fabric has developed in amphibolite refers to its banded nature. The minor mineral phases of amphibolite include epidote, ore minerals, and garnet. The feldspar alteration in granite is in the form of sericitization and normal zoning. The physical properties of river Panjkora and Kunai float i.e., water absorption, specific gravity, fine modulus, loss Angeles and soundness were within the range. Both petrographic and geotechnical properties suggested that these aggregates are suitable to be used as coarse aggregate in concrete. These must be present in the recommendation section at the end.