Coarse aggregate is the core of infrastructure for structures and transportation, and the mechanical strength of coarse aggregate has a great bearing on the life of concrete and asphalt mixtures. ASTM C131 gives consideration to examining the toughness and abrasion resistance of small-size aggregate, normally between 9.5 mm and 25 mm. The test employs the Los Angeles abrasion machine to simulate the mechanical forces aggregates undergo while being handled, transported, mixed, and in service life. Using controlled abrasion and impact, this standard enables quality control personnel and engineers to forecast the behavior of an aggregate under dynamic loading conditions. It is particularly critical for material selection in road bases, rail ballast, and heavily used concrete surfaces. The standard enables the aggregate to meet service expectations and withstand premature degradation that would negatively affect structural performance.
ASTM C131 Test Method
| Sample Mass and Size | 5000 ±10 g of oven-dried aggregate graded to a standard size group (e.g., A, B, C) selected from 9.5–25.0 mm. |
| Number of Steel Spheres | Twelve steel balls, each weighing approximately 390–445 g, are used to produce abrasion and impact. |
| Machine Rotation | The loaded drum is rotated at 30–33 revolutions per minute for 500 revolutions, creating controlled wear. |