| dc.description.abstract | A series of Foam Index measurements were made with 7 different AEAs (abietic
acids/resins/tall oil/tensides), 1 copolymer SuperPlaticizer, 2 different Fly Ashes, 1 blended (80/20
OPC/FA) cement, 2 different OPC and 2 inert fillers (limestone and quartz).
Foam Index = FI = required dosage of AEA to produce stable foam of a particular binder in a
w/p = 2.5 slurry where AEA is added dropwise to a container that is shaken and the foam observed
repeatedly until stable foam is obtained.
The objective was to investigate the efficiency of the different AEAs with varying Fly Ash
binders and the effect of mixing sequence of AEA and SP on the problems encounterd with air
entrainment with Fly Ash with variable carbon content.
The results show: that the ranking of the FI of the seven AEAs are the same for different
OPC/FA binders (with different carbon content); the more carbon the higher the FI, that “tensides”
are more robust than “resins”, and that FI in pure OPC binders are very low and not very different
for the 7 AEAs.
When adding SP before AEA the negative effect of carbon on foaming is reduced for most
AEAs, presumably due to adsorption of SP before AEA is introduced in the mix, whereas the FI of
some (presumably non-adsorbing) AEAs is not affected by SP addition. For those AEA/FA
combinations where the FI is affected by SP, adding SP with the AEA and adding SP after the AEA
reduces the efficiency of the AEA. Replacing blended cement with limestone filler and quartz filler
seems to affect FI in terms of the specific surface of the filler added: the more surface that is taken
away the more efficient becomes the AEA. Foaming with pure water | nb_NO |
