ABRASION VALUE OF AGGREGATE
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 (1.70 mm)
§ Cylindrical metal measure
§ Tamping Rod
§ Balance (0-10 kg)
§ Oven (300 0c)
fig:-Showing Los Angeles machine
PREPARATION SAMPLE
Test sample is dried in oven for a
period of four hours at a temperature of 100 to 110 C.
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.
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