This standard sets out the method for determining the average least dimension of aggregate particles by the use of vernier callipers or dial gauge or a slotted gauge. The method is applicable to aggregate of nominal size 5 mm and greater for sprayed bituminous surfacing.
NOTE: The first use of the term 'average least dimension' is attributed to F. M. Hanson, M M, in the paper 'Bituminous Surface Treatment of Rural Highways' published by New Zealand Society of Civil Engineers (Incorporated) in 1935.
Present practice is outlined in the NAASRA publication 'Principles and Practice of Bituminous Surfacing' 1980.
AS 1141.20:1982 history
1982AS 1141.20:1982 AS 1141.20 Directly measured average minimum size of aggregates