The objective of this investigation was comparing the penetration of
chloride ions in ordinary and air-entrained concretes containing a waste
material Fluidized Bed Combustion Fly Ash (FBCFA). All concretes were
tested with 15% and 30% cement replacement by FBCFA, with the same
water-binder ratio of 0.45. Two kinds of fly ash coming from fluid bed
combustion in two power plants in Poland have been used.
In this study the rapid chloride permeability test – Nordtest Method
BUILD 492 method – was used. The microstructure of the concrete was
analyzed on thin polished sections and the measurement of air voids
sizes and their distribution, using digital image analysis, was carried
on according to PN-EN 480-11:2008.
Obtained results have shown a significant influence of partial cement
replacement by FBCFA on the chloride ions movements in concrete. It has
been found that this kind of addition reduced considerably the chloride
ion penetration. The influence of air entrainment on the chloride
diffusion coefficients was also measured and it was shown that
application of air-entraining admixture for concretes with FBCFA reduce
the chloride diffusion coefficient but it should be used with caution.