ASTM C535-16 pdf free download.Standard Test Method for Resistance to Degradation of Large-Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine.
1.1 This Lest method covers testing sizes of coarse aggregate larger than 19 mm (¾ in.) for resistance to degradation using the Los Angeles testing machine (Note 1).
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound values given in parentheses are tbr information only.
4. Summary of Test Niethod
4.1 This test is a measure of degradation of mineral aggregates of standard gradings resulting from a combination of actions including abrasion or attrition. impact, and grinding in a rotating steel drum containing 12 steel spheres. 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 poilion is sieved to measure the degradation as percent loss.
5. Significance and Use
5.1 The test has been widely used as an indicator of the relative quality or competence of various sources of aggregate having similar mineral compositions. The results do not automatically permit valid comparisons to he made between sources distinctly different in origin. composition. or structure. Assign specification limits with extreme care in consideration of available aggregate types and their performance history in specific end uses.
6. Apparatus
6. 1 The Los Angeles Machine shall conform to the requ iremcnts of Test Method C131/C131M.
6.1.1 The operation and maintenance of the machine shall he as prescribed in Test Method C 131/C131 M.
6.2 Sieves, conforming to Specification E11.
6.3 Balance—A balance or scale accurate within 0.1 % of test load over the range required for this test
6.4 Charge—The charge (Note 2) shall consist of 12 steel spheres averaging approximately 47 mm (127/2 in.)ASTM C535 pdf download.