Title:
Concrete Q & A: Correcting a Frost-Heave Problem
Author(s):
Publication:
Concrete International
Volume:
25
Issue:
6
Appears on pages(s):
104
Keywords:
DOI:
Date:
6/1/2003
Abstract:
Last fall, we placed a 36,000 ft2 (3300 m2), 4-in.-thick (100 mm) concrete floor slab for a commercial building. The subgrade was silty soil, and the slab was placed directly on a polyethylene vapor barrier that rested on a 6-in.-thick (150 mm) layer of open-graded stone placed on thecompacted subgrade. The building is in a cold climate and it wasn’t heated when winter set in. The ground froze to a depth of 16 in. (400 mm) and frost heave caused the slab to rise from 1/2 in. (13 mm) in some spots to 1-1/4 in. (32 mm) in others. This was most noticeable at the building perimeter; in some places there was no frost heave. Now that the ground is thawing, is it possible that the slab will settle back to its original elevation under its own weight? Or is there a way to push the slab back to its original elevation?