Title: Concrete Q&A: Class F1 Exposure

Author(s):

Publication: Concrete International

Volume: 33

Issue: 5

Appears on pages(s): 71

Keywords:

DOI:

Date: 5/1/2011

Abstract:
One of our young engineers has raised a question about the strength of the concrete required in a footing. She’s pointed out that, although our standard contract documents call for 3000 psi concrete in foundation elements, Table 4.2.1 of ACI 318-08 defines Exposure Class F1 as “Concrete exposed to freezing-and-thawing cycles and occasional exposure to moisture.”1 Table 4.3.1 effectively states that normalweight concrete in Exposure Class F1 must be produced with a minimum water-cementitious material ratio (w/cm) of 0.45 and a minimum strength of 4500 psi. This requirement appears to be new. We’re in a cold climate. Does this provision apply to footings and foundation walls?