Aggregates which are flaky and/or elongated will often lower the workability of a concrete mix and may also affect long term durability. In bituminous mixtures flaky aggregate makes for a harsh mix and may also crack and break up during compaction by rolling.

This method described in EN933-4 measures the ratio of length to width of individual aggregate particles using a vernier calliper and a specially designed 3:1 length gauge.

Model No. Measuring Range Desc
81-0590 0 - 200 x 0.01 mm Vernier caliper
42-0821 - 3:1 Shape Index Calliper
81-0588 0 - 200 mm x 0.02 mm Vernier caliper

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.

Model No. Desc
42-0820 Length Gauge

A series of grid sieves formed from 5 mm diameter steel parallel bars securely fixed in a metal frame.

Model No. Passing Size Retained Size Slot width, mm
42-0300 5 4 2.5
42-0302 6.3 5 3.15
42-0304 8 6.3 4
42-0306 10 8 5
42-0308 12.5 10 6.3
42-0310 16 12.5 8
42-0314 20 16 10
42-0316 25 20 12.5
42-0318 31.5 25 16
42-0320 40 31.5 20
42-0322 50 40 25
42-0324 63 50 31.5
42-0326 80 63 40