The Coarse Aggregate Angularity Apparatus utilizes a scaled-up apparatus and procedure similar to that used for evaluation of fine aggregate. Gradation and void content data provide an indication of angularity, sphericity, and surface texture. As concluded by NCAT's work, test results relate to permanent deformation and fatigue cracking of asphalt. The test has therefore been recommended to evaluate aggregates for HMA pavement.
Aggregate is allowed to free fall from the funnel of a cylindrical hopper into a cylindrical measure. Excess heaped aggregate is struck off using the included bar, the mass is measured, and void content is computed.
The hopper, stand, and measure, are stainless steel. The apparatus also includes glass plate for calibration of the measure. A locator pin and circle on the bottom plate of the stand assure centering the measure below the hopper.
The apparatus measures 10x10x27in (254x254x686mm), WxDxH.
Meets Test Method: