Los Angeles Abrasion Test

Test Method(ASTM C131)

This test is a measure of degradation of mineral aggregates of standard grading’s resulting from a combination of actions including abrasion or attrition, impact, and grinding in a rotating steel drum containing a specified number of steel spheres, the number depending upon the grading of the test sample. As the drum rotates, a shelf plate picks up the sample and the steel spheres, carrying them around until they are dropped to the opposite side of the drum, creating an impact crushing effect. The contents then roll within the drum with an abrading and grinding action until the shelf plate picks up the sample and the steel spheres, and the cycle is repeated. After the prescribed number of revolutions, the contents are removed from the drum and the aggregate portion is sieved to measure the degradation as percent loss.

Scope

This test method covers a procedure for testing sizes of coarse aggregate smaller than 37.5 mm (11⁄2 in.) for resistance to degradation using the Los Angeles testing machine. A procedure for testing coarse aggregate larger than 19.0 mm (3⁄4 in.) is covered in Test Method C 535.

Significance and Use

This test has been widely used as an indicator of the relative quality or competence of various sources of aggregate having similar mineral compositions.

Nasir Abbasi
http://labksa.blogspot.com/