Concrete air entrainment too low
Concrete air entrainment too low
(OP)
Hi Everyone,
Today the first segments of many site retaining walls were poured. The air content of the concrete of the wall was tested at 2%.
Specified are:
4,000 psi concrete,
6% air +/- 1.5%,
W/C ratio of 0.4.
The mix has 2.85 cu ft of cement,
1 cu ft of type F fly ash,
10.6 cu ft of 1” coarse aggregate, and
6.4 cu ft of fine aggregate.
The wall in question will be exposed (no veneer), it will not be exposed to de-icing salts.
I consider the particular wall location to be an exposure category F1 (moderate: exposed to freeze thawing with occasional exposure to moisture.) That would require an air entrainment per ACI of 4.5% +/-1.5%, so a low end of 3%.
Is there supplemental testing on air entrainment that can be done on hardened concrete?
Is there a surface treatment that can help?
What would you do?
Thanks!
Today the first segments of many site retaining walls were poured. The air content of the concrete of the wall was tested at 2%.
Specified are:
4,000 psi concrete,
6% air +/- 1.5%,
W/C ratio of 0.4.
The mix has 2.85 cu ft of cement,
1 cu ft of type F fly ash,
10.6 cu ft of 1” coarse aggregate, and
6.4 cu ft of fine aggregate.
The wall in question will be exposed (no veneer), it will not be exposed to de-icing salts.
I consider the particular wall location to be an exposure category F1 (moderate: exposed to freeze thawing with occasional exposure to moisture.) That would require an air entrainment per ACI of 4.5% +/-1.5%, so a low end of 3%.
Is there supplemental testing on air entrainment that can be done on hardened concrete?
Is there a surface treatment that can help?
What would you do?
Thanks!
Eric McDonald, PE
McDonald Structural Engineering, PLLC





RE: Concrete air entrainment too low
RE: Concrete air entrainment too low
RE: Concrete air entrainment too low
waterproofing materials help freeze/thaw by reducing water penetration. If the breaks come well high and ripping it out is not prudent to the owner, a surface application of thoroseal may be in order. it also produces a nice surface.