Title:
Investigation of Air-Entraining Admixture Dosage in Fly Ash Concrete
Author(s):
M. Tyler Ley, Nathan J. Harris, Kevin J. Folliard, and Kenneth C. Hover
Publication:
Materials Journal
Volume:
105
Issue:
5
Appears on pages(s):
494-498
Keywords:
DOI:
10.14359/19979
Date:
9/1/2008
Abstract:
The amount of air-entraining admixture (AEA) needed to achieve a target air content in fresh concrete can vary significantly with differences in the fly ash used in the concrete. The work presented in this paper evaluates the ability to predict the AEA dosage on the basis of tests on the fly ash alone. All results were compared with the dosage of AEA required to produce an air content of 6% in fresh concrete. Fly ash was sampled from six separate sources. For four of these sources, samples were obtained both before and after the introduction of "low-NOx burners." Lack of definitive data about the coal itself or the specifics of the burning processes prevents the ability to draw specific conclusions about the impact of low-NOx burners on AEA demand. Nevertheless, the data suggest that modification of the burning process to meet environmental quality standards may affect the fly ash-AEA interaction.