Durability of alkali-activated concretes containing cement kiln by-pass dust

The aim of the presented work was evaluation of an effect of various conditions on the performance of two developed concretes based on alkali-activated slag and cement kiln by-pass dust (BD). BD was used as a partial replacement of natural aggregates while slag as an aluminosilicate precursor activated by a combination of waterglass and sodium hydroxide solution (resulting silicate modulus of 0.5). The concretes differed only in an activator dose which was 4 and 6% of Na2O with respect to the slag weight. The prepared specimens were sealed-cured for the first 28 days and then their resistance to freeze-thaw cycles and aggressive solutions (ammonium nitrate, acetic acid and sulphates) was tested. Evolution of dynamic modulus showed that both concretes resisted well to freeze-thaw cycles as well as to most solutions, where their dynamic modulus tended to increase in most cases or did not change significantly. Only the concrete with 4% Na2O showed poor resistance to acetic acid solution as the specimens completely disintegrated until 50 days.

Keywords

alkali-activated slag, durability, freeze-thaw, acetic acid, ammonium nitrate, sulphate, activator dose

Citation

IOP Conference Series: Materials Science and Engineering. 2021, vol. 1039, p. 1-8.
https://iopscience.iop.org/article/10.1088/1757-899X/1039/1/012012

Document type

Peer-reviewed

Document version

Published version

Language of document

en