4103.01 DESCRIPTION.
Liquid admixtures for PCC shall be approved by the Engineer. Evidence for the Engineer's evaluation, based on tests made in a recognized laboratory, shall be submitted to show the material meets requirements of AASHTO M 154 for air entraining admixtures and AASHTO M 194 for other liquid admixtures. A recognized laboratory is any laboratory regularly inspected by the Cement and Concrete Reference Laboratory of the National Institute of Standards & Technology. Tests may be made on samples taken from a quantity submitted by the Contractor for use on the project or on samples submitted and certified by the manufacturer as representative of the admixture to be supplied. Unless approved by the Engineer, admixtures containing more than 1.0% chloride ions shall not be used.

Inspection and acceptance of liquid admixtures for PCC will be in accordance with Materials I.M. 403.

A. Air Entraining Admixtures.
Provisions shall be made to stir, agitate, or circulate air entraining admixtures prior to use to insure a uniform and homogeneous mixture.

B. Retarding and Water Reducing Admixtures.
The retarding and water reducing admixtures used shall be compatible with the air entraining agent used. The admixtures shall be used in amounts recommended by the manufacturer for conditions which prevail on the project or in accordance with Materials I.M. 403 and as approved by the Engineer. When used, they shall be introduced into the mixer after all other ingredients are in the mixer. Other procedures may be approved by the Engineer. Retarding and water reducing admixtures shall be agitated prior to and during their use in accordance with Materials I.M. 403. When fly ash is used in the concrete, the liquid admixture dosage rate shall be applied to both the cement and fly ash weight (mass) combined.

C. Other Admixtures.
Other admixtures may be used with the approval of the Engineer in accordance with the manufacturer's recommendations.