Author(s)

Alexey Brykov^1*, Anna Anisimova¹, Natalya Rozenkova¹, Mohammed Hadi², Maxim Mokeev³

¹Department of Chemistry of Substances and Materials, Saint-Petersburg State Institute of Technology, St. Petersburg, Russia.
²Thi-Qar University, Nasiriyah, Iraq.
³Institute of Macromolecular Compounds, St. Petersburg, Russia.

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.

Alkali-Silica Reaction, Sulfate Attack, Mitigation, Aluminum Sulfate, Iron Sulfate, Portland Cement

Brykov, A. , Anisimova, A. , Rozenkova, N. , Hadi, M. and Mokeev, M. (2015) The Impact of Aluminum- and Iron-Bearing Admixtures on the Resistance of Portland Cement Mortars to Alkali-Silica Reaction and Sulfate Attack. Materials Sciences and Applications, 6, 539-548. doi: 10.4236/msa.2015.66058.