1.1 This test method covers the determination of the quantity of air-entraining admixture adsorbed by coal fly ash from an aqueous solution. The result is expressed as the volume of air-entraining admixture adsorbed per unit mass of coal fly ash (mL AEA/g fly ash). The quantity of air-entraining admixture adsorbed is a function of the solutions air-entraining admixture concentration. 1.2 The units in SI are to be considered as standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations to use.
Keywordscoal fly ash; air entraining admixture; direct adsorption isotherm
This test method is a modified version of ASTM C3860-98(2008). The purpose of this test method is to assess quantitatively the adsorption capacity of a specific coal fly ash for a specific air entraining admixture (AEA). Determination of the adsorption capacity is accomplished by establishing the adsorption isotherm for the combination of materials being assessed. The isotherm is a plot of AEA adsorbed versus the initial bulk concentration of AEA in the concrete mixture. The adsorption capacity is expressed in units of mL AEA/g ash. The users will be any concrete producer preparing concrete using fly ash. This test method addresses a common problem with fly ash in which the ash affects the air entrainment in concrete.
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development