What is the Micro Deval test?
1.1 Use this test procedure to determine the Micro-Deval abrasion loss of coarse, intermediate, and fine aggregates. This loss is an indication of an aggregate’s resistance to abrasion, weathering, and degradation using the Micro-Deval testing equipment with abrasive stainless steel balls and water.
Why was Micro Deval test developed?
The basis for this method was developed in France during the 1960s and provides a measure of toughness, abrasion resistance, and durability of mineral aggregates as they are ground with steel balls in the presence of water.
What is Dorry abrasion test?
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 The Dorry Abrasion Test was superseded in 1951 by the current AAV test.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.
What is the difference between LA abrasion test and Micro Deval test?
LA Abrasion and Micro Deval tests are both drum tests where degradation occurs by rotating the aggregates together with steel balls. The LA Abrasion tests dry aggregates, while the Micro Deval tests wet or soaked aggregates.
What is Los Angeles abrasion value?
What is abrasion value test? Abrasion Test is the measure of aggregate toughness and abrasion resistance such as crushing, degradation and disintegration. The percentage wear of the sample aggregates due to rubbing with steel balls is determined and is known as Los Angeles Abrasion Value.
What is Los Angeles abrasion?
The Los Angeles (L.A.) Abrasion Test is widely used as an indicator of the relative quality of aggregates. It measures the degradation of standard gradings of aggregates when subjected to abrasion and impact in a rotating steel drum with an abrasive charge of steel balls.
Which equipment is used for abrasion test?
Apparatus Used for Abrasion Test Abrasive ball: which is made from cast iron or steel ball. It has a diameter of about 48 mm and each ball weighs between 390 and 445 grams. At the time of the test, six to twelve balls are placed in the drum along with the material at the time of the test.
What is abrasion value?
The abrasion value of an aggregate is the value that determines aggregate toughness and abrasion resistance. It includes properties of aggregate such as crushing value, degradation, and disintegration.
Which apparatus is used for aggregate abrasion test?
This test helps to determine the abrasion value of coarse aggregates as per IS: 2386 (Part IV) – 1963. The apparatus used in this test are Los Angles abrasion testing machine, IS Sieve of size – 1.7mm, Abrasive charge – 12 nos. cast iron or steel spheres approximately 48mm dia.
What is the normal range for sand equivalent value?
Typical Values Typical sand equivalent values range from less than 30 to more than 90.
What is the micro Deval testing machine?
The Micro Deval Testing Machine used to determine the resistance of wear for 25-50mm size aggregates. The machine consists of a steel frame, four stainless steel cylinders, and 25kg of 10 mm diameter stainless steel spheres. Fitted with an automatic digital counter that allows the machine to stop automatically at preset number of revolutions.
What is the micro-Deval test?
The Micro-Deval test was investigated to determine if it provided a better means of establishing aggregate quality for use in pavements. During the summer of 1999, ODOT purchased a Micro-Deval abrasion tester to evaluate aggregate durability of known and new sources.
What is the difference between the MTO and Deval tests?
With the low loss natural sand, the MTO attrition test has the widest var iation, but this is mainly because of the low mean loss of 4. 1 percent obtained in this test with this material, which distorts variability when using coefficient of variation. The micro Deval test had the lowest within-laboratory variation of about 1 to 2 percent.
What is the difference between La abrasion test and micro-Deval test?
The LA abrasion test may not adequately represent the aggregate durability. The Micro-Deval test was investigated to determine if it provided a better means of establishing aggregate quality for use in pavements. During the summer of 1999, ODOT purchased a Micro-Deval abrasion tester to evaluate aggregate durability of known and new sources.