Entrained air too low
Entrained air 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 a surface treatment that can help?
What would you do?
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 a surface treatment that can help?
What would you do?
Eric McDonald, PE
McDonald Structural Engineering, PLLC






RE: Entrained air too low
RE: Entrained air too low
RE: Entrained air too low
Don't know if that will work, but might be worth finding out.
RE: Entrained air too low
I will have the GC research and propose a surface sealant.
Eric McDonald, PE
McDonald Structural Engineering, PLLC