SUMMARY Take approximately 5000g sample of aggregate retained on the No. 12 (1.70 mm) sieve is placed inside a rotating steel drum containing a specified number of steel spheres or "charge". As the drum rotates, a shelf inside the drum picks up the aggregate and steel spheres. The shelf carries them around until they drop on the opposite side of the drum, subjecting the aggregate to impact and crushing. Then, the aggregate is subjected to abrasion and grinding as the drum continues to rotate until the shelf picks up the contents, and the process is repeated. The drum is rotated for a 500 number of revolutions at 30-33rpm. Afterward, the aggregate is removed from the drum and sieved on a No. 12 (1.70 mm) sieve. The aggregate retained on the sieve is weighed and the difference between this weight and the original weight is expressed as a percentage and reported as the L.A. abrasion loss value. INTRODUCTION Tests for resistance to abrasion in crushed rock, slag, crushed and uncrushed gravel can using Los Angeles testing method. Features welded structural steel frame, fabricated 1/2”-thick (913mm) abrasion-resistant steel drum, removable shelf bolted to drum and balanced drum assembly for easy
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
SUMMARY
Take approximately 5000g sample of aggregate retained on the No. 12 (1.70 mm)
sieve is placed inside a rotating steel drum containing a specified number of steel spheres
or "charge". As the drum rotates, a shelf inside the drum picks up the aggregate and steel
spheres. The shelf carries them around until they drop on the opposite side of the drum,
subjecting the aggregate to impact and crushing. Then, the aggregate is subjected to
abrasion and grinding as the drum continues to rotate until the shelf picks up the contents,
and the process is repeated. The drum is rotated for a 500 number of revolutions at 30-
33rpm. Afterward, the aggregate is removed from the drum and sieved on a No. 12 (1.70
mm) sieve. The aggregate retained on the sieve is weighed and the difference between
this weight and the original weight is expressed as a percentage and reported as the L.A.
abrasion loss value.
INTRODUCTION
Tests for resistance to abrasion in crushed rock, slag, crushed and uncrushed
gravel can using Los Angeles testing method. Features welded structural steel frame,
fabricated 1/2”-thick (913mm) abrasion-resistant steel drum, removable shelf bolted to
drum and balanced drum assembly for easy rotation by hand. Enclosed chain drive rotates