Specific Assessment of Coarse Aggregate ( gravels ) From Selected Quarries in Salahaddin , Middle Iraq

Abstract

Six gravely samples are studied in laboratory for specific assessment, according to Iraqi & American standards. Grain distribution results indicaete , all samples are uniform graded , some particles diameter are absence . Uniformity and Concavity coefficient values are (less than 4, less than 1) respectevly , Samples (1 , 4 , 5) are suitable, while (2 ,3 ,6) are not suitable , total dissolved salts% ,gypsum cotent% , organic materials% are acceptable . most gravel shapes are rounded , subronded , anguler , subanguler with percentage ( 76% - 81% ) , and flattening shapes about (19% - 24%) . Gravels uncoated with (salts , gypsum , organic materials , clays) , soft materials , noncrystallized silica minerals and mica , schist , gneiss minerals are absent. Sedimentary gravels forming about (77%), igneous gravels (7%) ,metamorphic gravels (l6%) . From XRD the following minerals identified Quartz mineral very dominate –dominate ,calcite ,dominate ,orthoclase moderate ,plagioclase moderate-trace , ( aragonite ,gypsum. ,dolomite ,halite ,chlorite ,kaolinite , talc )very trace .