Aggregate Suitability of the Late Permian Wargal Limestone at Kafar Kot Chashma Area, Khisor Range, Pakistan

Abstract

This study was carried out for the investigation of the Late Permian Wargal limestone at Kafar Kot Chashma area, Khisor Range to determine its suitability as an aggregate that is used in road construction and civil structures with the help of geological engineering testing. The results of geological engineering testing of Wargal limestone samples show the tolerable values of all standard engineering parameters including the Loss Angles Abrasion value (23.37%), Aggregate impact (16.8%), Crushing value 13.1%, Unit weight 1.67, Soundness (1.007%), Specific gravity (2.70), Water Absorption (0.48%), Flakiness Index (6.5%), Elongation value (7.1%), Coating of bitumen (> 95%), stripping of bitumen (<5%), California Bearing Ratio (CBR) value (93.6%), Maximum Dry Density 2.307g/c and Optimum Moisture Content (5.79%). As per different International and National Standards like AASHTO, ASTM, BS and NHA, the mentioned results of various engineering tests were within the tolerable limits. The petrography of the selected samples of the Late Permian Wargal limestone revealed very minor value of quartz (0.5%), hematite/limonite (0.6%) and clay content 1.0% showing the insignificant threat of ASR. The values of dolomite are limited to (1%) which shows that there is no ACR reaction with ordinary Portland cement. The results of geological and engineering parameters of the study area strongly suggest its suitability as a potential aggregate (i.e. for the base course, subbase course, cement concrete and asphalt) in the road construction.