Gravel
Revision as of 13:45, 11 October 2017 by Muwaffaq Al-Awad (talk | contribs)
For advice on decorative surface aggregates see Stone
- Granular material for underdrains should be clear crushed 20 or 50 mm diameter stone graded in accordance with ASTM D 2940,
- The 20 mm clear crushed aggregate permits the use of an overlaid layer of high performance bedding (HPB) as a choker layer,
- The void space ratio should be > 0.35 (or > 35%)
All gravel should meet the following criteria:
- Maximum wash loss of 0.5%
- Minimum durability index of 35
- Maximum abrasion of 10% for 100 revolutions and maximum of 50% for 500 revolutions