ASTM C535-12 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 test method covers testing sizes of coarse aggregate larger than 19 mm (¾ in.) for resistance to degradation using the Los Angeles testing machine (Note I).
7. Sampling
7.1 Obtain the field sample in accordance with Practice D75 and reduce to an adequate sample size in accordance with Practice C702.
8. Test Sample Preparation
8.1 Wash the reduced sample and oven dry at 110 ± 5°C(230 ± 9°F) to substantially constant mass, separate into
individual size fractions, and recombine to the grading of TableI most nearly corresponding to the range of sizes in the aggregate as furnished for the work. Record the mass of the sample prior to test to the nearest 1 g.
9. Procedure
9.1 Place the test sample and charge in the Los Angeles testing machine and rotate the machine at 30 to 33 r/min for 1000 revolutions (Note 3). After the prescribed number of revolutions, discharge the material from the machine and make a preliminary separation of the sample on a sieve coarser than the 1.70-mm (No. 12) sieve. Sieve the finer portion on a 1.70-mm sieve in a manner conforming to Test Method C 136. Wash the material coarser than the 1 .70-mm sieve and oven dry at 110 ± 5°C (230 ± 9°F) to substantially constant mass, and determine the mass to the nearest I g
9.1.1 If the aggregate is essentially free of adherent coatings and dust, the requirement for washing after the test is optional. However, in the case of referee testing. the washing procedure shall be performed. Elimination of washing after test will seldom reduce the measured loss by more than about 0.2 % of the original sample mass.
11. Report
11.1 Report the following information:
11.2 Identification of the aggregate as to source, type. and nominal size, and
11.3 Grading designation from Table 1 used for the test, and
11.4 Loss by abrasion and impact of the sample expressed to the nearest 1 % by mass.
12. Precision and Bias
1 2. 1 Precision
12.1.1 Single Operator Precision—The single-operator coefficient of variation has been found to be 2.7 %. Therefore, results of two properly conducted tests by the same operator on the same material are not expected to differ by more than 7.6 % of their average.ASTM C535 pdf download.