Digital Foam Index Test for Air Entrainment Interactions

Abstract The digital foam index test (D-FIT) has been developed to quantify air-entraining agent (AEA) interaction with cement-fly ash-water mixtures and improve the repeatability of the traditional foam index test. The D-FIT acquires and analyzes videos of the evolving foam layer in a cementfly ash-water mixture as sequentially higher amounts of AEA are added. The proposed computer vision technique and deep-learning algorithm quantify the empty area on the surface and then calculates the percentage of the surface covered with foam. As part of the D-FIT, two new parameters have been defined. The AEA dosage required to produce a metastable foam is called the foam stability, whereas the incremental AEA dosage beyond the foam stability to achieve a foam layer covering the entire container surface is called the foam efficiency dosage. The summation of the foam stability and foam efficiency dosage is the traditional foam index value. Based on five ashes tested, the foam efficiency from vinsol resin-based AEA was higher than the sulfonate–based AEA, but the foam stability dosage was greater for the sulfonate–based AEA. Finally, the ratio of foam index to foam stability was not linked to the loss on ignition of ashes but more related to the interaction of the AEA type with the cement-fly ash mixture.