A better understanding of the influence of aggregate gradationon the shear resistance and volumetric properties of asphalt mixturesis needed to maximize the shear and rutting resistance in asphaltmixtures. Eighteen mixtures were prepared with different coarseaggregate (> 2.0 mm) gradations ranging from Stone Matrix Asphalt(SMA) to those corresponding to the maximum density line. TheGyratory Shear (Gs measurements indicated the gradation of thecoarse aggregate fraction (> 2.0 mm) was related to the shearresistance of the mixtures. Coarseness, shape, and position ofthe gradation curve relative to the maximum density line affectedthe shear resistance. Mixtures including both coarse and fineaggregate fractions verified the test results obtained from thecoarse-aggregate only mixtures. It was evident that coarse aggregategradations controlled the shear resistance of the mixtures eventhough fine aggregate dilated the coarse aggregate structure.Crumb rubber modified (CRM) asphalt binders were generally foundto have little effect on the air void content and shear resistance(Gs) of coarse- graded (e.g., SMA) mixtures.