Comparative study of iron (III) sulfate and aluminum as inhibitors of alkali-silica reactions

In this paper, a comparative study of the efficacy of aluminum and iron (III) sulfates as inhibitors of alkali-silica reactions (ASR) is described, in accordance with the accelerated method, GOST 8269.0, and their effect on sulfate resistance of cement/sand mortars in accordance with the procedure close to ASTM C 1012 . It is shown that both additives are effective ASR inhibitors, but ferrous sulfate, unlike aluminum sulfate, does not cause a sharp reduction in the initial setting time of the cement paste and does not cause sulfate corrosion. The inhibitory effect of the additives is due to Ca(OH)2 binding, colmatation of the pores due to the formation of ettringite and other products, and to the reduction in pH of the pore fluid.

Author: A.S. Brykov, A.V. Anisimova, N.S. Rozenkova, M.V. Mokeyev

Section: Science and production

Keywords: alkali-silica reactions, inhibitor, aluminum and ferrous sulphates, sulphate resistance, cement-sand mortar