Objective

For determination of the aggregate abrasion value of coarse aggregate. 

Reference Standards

IS: 2386 (Part IV)-1963 Methods of test for aggregate for concrete Part IV Mechanical Properties.

Equipment & Apparatus 

• Los Angeles machines
• Sieves (1.70mm)
• Cylindrical metal measure
• Tamping Rod
• Balance (0-10kg)
• Oven (300⁰c)

Preparation sample

Test sample is dried in oven for a period of four hours at a       temperature of 100 to 110C.

Procedure

1. The required weight of test sample(A) is selected conforming to one of the grading mentioned in Table II of  IS : 2386 (Part IV) – 1963.
2. The test sample and the abrasive charge is to be placed in the machine and rotated at a speed of  20 to 33 rev/min.
3. For grading A, B, C & D [as per Table II of IS : 2386 (Part IV)- 1963] the machine is to be rotated for 1000 revolutions.
4. At the completion of the test, the material is discharged from the machine and separation of the sample is made on 1.70 mm. IS sieve.
5. The material coarser than 1.70 mm. IS sieve is washed, dried accurately weighed to the nearest gram (B).

Calculation

The difference between the original weight and the final weight of the test sample is expressed as a percentage of the original weight of the test sample.

Report

The mean of the two results is reported to the nearest whole number as the aggregate abrasion value of the tested material. 

Safety & Precautions

• Use hand gloves while removing containers from oven after switching off the oven.
• Use safety shoes, mask & aprons at the time of test.
• Before testing, machine should be checked.
• After test electric supply should be off.
• Thoroughly clean & dry the container before testing.
• The drum & the cover of the opening should be cleaned thoroughly before & after every test.