Volume 5, Issue 7 (July 2008)
The Use of the Foam Index Test to Predict Air-Entraining Admixture Dosage in Concrete Containing Fly Ash: Part II—Development of a Standard Test Method: Apparatus and Procedure
The foam index test can be useful for predicting air-entraining admixture (AEA) dosage in concrete or for evaluating AEA interaction with other mixture ingredients. The test is sensitive to several factors including container type and fullness, volume of materials, agitation, pipette precision, and others. This study isolates several key factors such as container dimensions and fullness, mixing procedure, time permitted for AEA-cm-water interaction, and time permitted for drainage of unstable foam; and examines their influence on foam index test results. Recommendations for a standard test are proposed.