Determination of Aggregate Abrasion Value
The test gives a measure of the resistance of aggregate to surface wear by abrasion. The Dorry Abrasion Test was superseded in 1951 by the current AAV test.
Inadequate abrasion resistance of road-surfacing aggregates means an early loss of the texture depth required to maintain high-speed skidding resistance.
Two specimens are pressed against the surface of a steel disc rotating in a horizontal plane, with a force of 0.365 newtons per sq. centimetre. Sand, fed by hoppers, is used as an abrasive. After 500 disc revolutions the amount of material abraded is measured by calculation of the weight loss of the aggregate.
The percentage loss in mass of chippings as known as the 'Aggregate Abrasion Value' (AAV), and ranges from about 1 for hard flints to over 16 for aggregates normally considered too soft for use in road surfaces.
- Heavy duty mainframe on adjustable anti-vibration pads
- Steel lap wheel 610 mm diameter
- Precision machined steel shaft and sealed bearings
- Resilient mounted electric motor
- Totally enclosed, grease filled gear box
- Scraper blades for sand removal
- Predetermined revolution counter
Two specimen moulds
Two flat plates
||0.79 cubic metres
| Electrical Supply
||230V 50Hz 1ph
Click to view a PDF file of the User Guide
A user guide is available to download from the Impact web site www.impact-test.co.uk