AASHTO - American Association of State Highway and Transportation Officials
Scope
This specification covers porous nonreinforced concrete pipe for use in underdrains. This specification is applicable for orders in either SI units (M 176M) or in inch-pound units (M 176). SI units and inch-pound units are not necessarily equivalent. Inch-pound units are shown in brackets in the text for clarity@ but they are the applicable values when the material is ordered to M 176.