Length Gauge As Per IS

Length Gauge As Per IS

Purpose:
This instrument is used to determine the elongation index of aggregates. Particle is elongated when its length (longest dimension) is more than 1.8 of the midsize of the sieve fraction.

Significance & Use:
This method classifies aggregate elongation by measuring the length of individual particles. The test is not applicable to material retained on a 63.0 mm BS test sieve.

Construction Details:
Consists of a hard wood base with vertically mounted metal studs
Eight metal studs are mounted.
Aggregate to be classified is separated into seven sieve fractions from 63 to 6.3mm, and each fraction is examined separately.
The mass of all elongated particles (failing to pass between pins) as percent of the sample is the elongation index.
The distance between nails is applied according to following table.