Monday, September 1, 2008

aggregate size in elevated structural slab

I have another contractor requesting to use small rock (3/8" pump) mix for an elevated slab (3" concrete with WWM reinforcing over 0.6C 28 ga. decking over joists 24" o/c) mearly so it can be pumped. I've always been of the opinion 3/4" rock mix shall be used as pump mixes tend to present more shrinkage cracks and it's a "structural" slab. I know it's a durability issue for a slab on grade, but what about an elevated slab (walking traffic only)? I'm not finding any reference that helps one way or the other. After another round of research I'm thinking it shouldn't be a problem with WWM being used. Any thoughts?
 
Thank you.
 
David Schonacher Jr., P.E.
AvantiGroup
consulting engineers
1095 E. Brandon Blvd.
Brandon, FL 33511
Phone 813-655-2884, Ext. 301
Fax 813-655-2886