TITLE:
The Impact of Aluminum- and Iron-Bearing Admixtures on the Resistance of Portland Cement Mortars to Alkali-Silica Reaction and Sulfate Attack
AUTHORS:
Alexey Brykov, Anna Anisimova, Natalya Rozenkova, Mohammed Hadi, Maxim Mokeev
KEYWORDS:
Alkali-Silica Reaction, Sulfate Attack, Mitigation, Aluminum Sulfate, Iron Sulfate, Portland Cement
JOURNAL NAME:
Materials Sciences and Applications,
Vol.6 No.6,
June
16,
2015
ABSTRACT: Study of sulfate resistance of mortars with aluminum- and iron-bearing admixtures (Al(OH)3, Al2(SO4)3, FeSO4, Fe2(SO4)3) in conditions close to those established in ASTM C 1012, and the study
of the mitigation effect of these admixtures on alkali-silica reaction in accordance with accelerated
“mortar bar” test ( GOST 8269.0, ASTM C 1260) were performed. Iron (II) and (III) sulfates show
ability for mitigation alkali-silica reaction, while also, in contrast with Al-bearing substances, do
not induce the drastic reducing of the initial setting time and do not promote the progress of sulfate
corrosion. Compared with FeSO4, iron (III) sulfate has moderate deleterious impact on the
early strength of cement paste and can be of interest alone as an inhibitor of ASR. Iron (II) sulfate
may be used together with aluminum sulfate to offset the accelerating effect of the latter on the
setting of cement paste and to reduce a risk of sulfate corrosion. During prolonged water storage,
the mortar elongation and secondary ettringite formation do not occur, even when Al2(SO4)3 is
available. Therefore, the investigated admixtures cannot act as agents of internal sulfate attack,
however, Al2(SO4)3 can enhance the outer sulfate attack.