Ceramics-Silikáty 39, (3) 105 - 111 (1995)

This paper deals with the properties of mortars containing the mixtures of Portland cement clinker, zeolite tuff and gypsum. The mortars consisting of mixtures with 87.42 to 87.99 % of Portland cement clinker, 9.62 to 9.99 % zeolite tuff and 2.02 to 5.63 % of gypsum were prepared and compared to zeolite-free control mortar with 95.2 % of Portland cement clinker and 4.98 % of gypsum. The 1 095 day compressive strength of zeolite-modified mortars is comparable to that in the control one. Contemporarily a portion of micropores with radius less than 100 nm in the pore structure of zeolite-modified mortars is larger than in the control one. The presence of zeolite tuff in the mortars has not negative effect on steel corrosion.