Title:
Concrete Q & A: Was Fresh Concrete Frozen?
Author(s):
Publication:
Concrete International
Volume:
30
Issue:
4
Appears on pages(s):
91-92
Keywords:
DOI:
Date:
4/1/2008
Abstract:
A cold-weather project of mine includes normalweight concrete slabs placed on metal decking supported by structural steel framing. Test results for fieldcured cylinders were low, with the highest 28-day test result at 1700 psi (12 MPa) for what was supposed to be a 3500 psi (24 MPa) design. I believe the fresh concrete in the slab may have frozen. How can I tell if the low strength is due to freezing? What strength loss is expected when fresh concrete is frozen? Also, if the concrete didn’t freeze, could strengthtest results this low be caused by slow strength gain because of low temperatures?