Abstract:
Sulphate resistance of cement suspensions made from ordinary Portland cement (reference PC) and
bentonite, and those where bentonite was completely replaced by zeolite and silica fume in the
weight ratio of 1:3 and 3:1 is reported in this paper. The suspension mixture composition was
modified by fine iron powder addition. The mortars were made from reference PC and Portland -
pozzolan cement with 35 wt. % of zeolite addition (ZBC). Suspensions (to 20 wt. % of zeolite -
silica fume addition, W/C = 1.0) and mortars (cement to sand weight ratio of 1:3 and W/C = 0.6)
were prepared and tested in water and sodium sulphate solution for 180 days (suspension) and 720
days (mortar) using 20 x 20 x 120 mm and 40 x 40 x 160 mm specimens. The results show that
zeolite addition markedly increased the sulphate resistance of cement suspension and mortar.
