Micro-Deval Apparatus is a second-generation, state-of-the-art machine. A sophisticated electronic controller with an optical sensing system accurately tracks test time, total revolutions, and rpm of jars. Test duration may be controlled by either elapsed time or total revolutions. Jars stop within a fraction of one revolution at test termination. Jar revolution and speed data may also be used as a verification of machine performance. The MD-2000 meets current ASTM, AASHTO, and Canadian test methods, as well as more stringent Texas DOT requirements. This contemporary version of the Micro-Deval test should not be confused with older versions originating in Europe which use different equipment and test protocol.
The increasingly popular Micro-Deval test measures the abrasion resistance and durability of fine and coarse mineral aggregates. An aggregate sample is placed in a sealed stainless steel jar with an abrasive charge of up to 5,000g of 9.5mm diameter stainless steel balls and water, then rotated at 100rpm for two hours. Aggregate quality is determined by percentage loss in gradation results at completion. Smaller equipment size, lower sample quantities, and a simpler procedure make the method easier and less costly to perform than test methods.
The jars revolve behind closed Lexan™ doors with safety interlocks so no moving parts are exposed during operation. Other manufacturers use separate timers to control test duration, which does not permit tracking of jar revolutions or speed and allows variations up to ±6% of the optimum number of revolutions. In addition, other machines rotate the jars on unguarded open rollers, creating a potentially hazardous situation.
A Micro-Deval machine is a two-tier unit with a sturdy steel frame. Each tier carries one stainless steel 5L jar, 194mm ID, 170mm depth with locking cover. Power to the rubber-covered rollers is supplied by a 3/4hp electric motor through a gear transmission and chain drive. The unit is supplied with two jars and two sets of 5,500g abrasive charges. A magnet is included to assist in removing the abrasive charge after the test is complete. For additional sample preparation capacity and greatly reduced testing times, order additional HMA-920 jars and HMA-922 Abrasive Charges.
Read our Micro-Deval Test Method blog for more information regarding the test.
- Easiest and safest in the industry
- Multi-function electronic controller tracks time, speed, and total revolutions
- Smaller equipment size and lower sample quantities provide a simple, cost-effective operation
- Compliant with ASTM, AASHTO, Canadian and stringent Texas DOT specifications
- LexanTM doors with safety interlocks to enclose moving parts
- Micro-Deval Apparatus (115V/60Hz, 230V/50Hz, or 230V/60Hz)
- Two jars
- Two sets of 5,500g abrasive charge
- Magnet to assist in removing abrasive charge after test completion