§ 15.01.1090. Air content and consistency.

A.

Air-entrainment. Concrete that after curing will be exposed to freezing temperatures while wet shall contain entrained air within the following limits:

Normal Maximum Aggregate Size (inches)	Total Air Content Percent by Volume Per Cubic Foot
3/8	6 to 9
½	5 to 8
¾	4 to 8
1—1½	3.5 to 6.5

 

B.

Consistency. Unless otherwise specified in these specifications, unreinforced concrete flat work shall have a slump range of one to three inches, reinforced concrete shall have a slump range of two to four inches unless super plasticized and mass concrete shall have a slump range of two to six inches.

C.

Rejection of concrete due to inconsistency or air entraining. Should air-entrainment fall below the minimum value set as determined from two or more tests in a batch, the city may reject such concrete. Once the "job mix," as specified in Section 15.01.1100, has been established and the slump requirements are known, if slump measurements are inconsistent with the mix, the engineer may reject the concrete if the adequacy of the batch is in question. Inconsistency shall be based on at least two slump tests from a load with the slump falling more than two inches below the set slump for the "mix" on both tests.

The first slump test will be taken after the first yard of concrete has been placed. If this test fails a second test will be taken immediately after.

(Ord. No. 2007-07-31, §§ 12.4—12.4.3, 7-10-2007)