One or more layers of material placed immediately above the formation.
Good quality crushed and graded aggregate used as the top layer of road construction, immediately below the bitumen- or cement- bound surfacing. A valuable product, much of which is provided by primary crushed rock aggregates like granite or limestone. Crushed concrete can be processed to provide a completely satisfactory alternative.
Found on http://www.encyclo.co.uk/local/20710
Sub'-base` noun (Architecture)
The lowest member of a base when divided horizontally, or of a baseboard, pedestal, or the like. Found on http://www.encyclo.co.uk/webster/S/220
• (n.) The lowest member of a base when divided horizontally, or of a baseboard, pedestal, or the like.Found on http://thinkexist.com/dictionary/meaning/sub-base/
No exact match found