Title: Resistance of Hybrid Cement after 5 Years of Exposure to 5% Na2SO4
Author(s): Ivan Janotka, Pavel Martauz, and Michal Bacuvcik
Publication: Symposium Paper
Appears on pages(s): 77-92
Keywords: hybrid cement; properties; microstructure; sulfate resistance; durability
Hybrid cement (H-CEMENT) is an innovative cement of the producer from Slovakia. H-CEMENT is suitable for the production of ready-mixed concrete of compressive strength classes up to C 30/37 (4350/5370 psi) along with shrinkage-reducing and alkali-aggregate reaction-mitigating properties. The results of 5-years of exposure of H-CEMENT mortar in an aggressive sulfate solution are compared with two reference cement mortars made either with CEM I or sulfate-resistant CEM I SR 0. Sulfate resistance of H-CEMENT was evaluated in the regularly-renewed aggressive 5% solution by none-destructive tests (dynamic modulus of elasticity and length changes), destructive tests (flexural and compressive strength), microstructure studies (XRD, TG-DTA and SEM), wet chemical analyses (mainly the estimation of SO3 content), and pore structure technique (MIP). The results give evidence of the same high sulfate resistance for H-CEMENT as that for CEM I SR 0 with C3A = 0.