Hillhead 2012
19 - 21 June 2012
International live demonstration show for the quarrying, recycling and heavy construction industries at Hillhead Quarry, Buxton, UK.
penetration grade
[img_assist|nid=11988|title=|desc=|link=none|align=right|width=149|height=214]The degree of hardness of a binder as determined by the standard penetration test.
The monthly journal for the quarry products industry.