Used to determine the percentages of flat particles, elongated particles,or flat and elongated particles in coarse aggregates. Individual particles of aggregate of speciﬁc sieve sizes are measured to determine the ratios of width to thickness, length to width, or length to thickness. The axis position can be adjusted to provide the desired ratio of 1:2, 1:3, 1:4 and 1:5.
According to ASTM, both Method A and Method B can be performed using R037, while:
Method A is a reflection of the original procedure as developed prior to Superpave and is intended for all non-Superpave applications.
Method B is a comparison of the maximum particle dimension to the minimum particle dimension and is intended for use with Superpave specifications.