Table of Contents
Abrasion test on aggregates is carried out to find the hardness quality of the aggregate material . Hard stones can provide resistance to wear against abrasive charge. In Los Angeles test for finding abrasion value of the aggregates, the aggregates and abrasive charge are placed together in a drum. The drum is rotated to 500 revolution or 1000 revolution depending upon the gradings of aggregate.
The fines generated during this action after passed through 1.72 mm sieve. The amounts passing through is used for getting an inference about the abrasion value and the use of the aggregates.
Test Method for Los Angelis abrasion test
The grading of aggregates as given in IS 2386 is as follows:
The test shall be conducted on clean oven dried and cooled aggregates.
The aggregates shall be sieved for different fractions.
Select the sieve-based material fraction sample for which test is to be done from the above table. Let its weight be W1. Select the grading and the requirements of charge from the table below:
Add the aggregates to Abrasion testing machine.
Add the balls to the aggregates and rotates the drum at about 30 revolutions per minute for 500 or 1000 revolution as per suggestions given in code for different type of gradings
(Los Angeles abrasion testing machine drum is rotated at a speed of
20 to 33 rev/min. For gradings A, B, C and D, the drum shall be rotated for 500 revolutions; for gradings E, F and G, it shall be rotated for 1000 revolutions.)
After the abrasive action is over, take out the material and pass it through 1.7 mm sieve. Wash the material over this sieve, collect it, oven dry it, cool it and find the weight of the material. Let it be W2
Find the lossof weight due t abrasion =W1-W2
The abrasion percentage of the sample = (W1-W2)/W1 * 100
Format for Aggregate Abrasion Test
Los Angeles abrasion test
For aggregate use to resist wear, Max 30 percent; For non-wearing surface, the value is 50 percent Max.
IS : 2386 (Part 5)
Water Quality for Consumption & Construction——— (part 1)