The study deals with high-temperature properties ofgypsum-free Portland cement (GF cement) based on ground clinker of Portlandcement and processed with additions of Na2CO3 and ligninesulphonate. An admixture of Al(OH)3 is sufficient for eliminatingCa(OH)2 from hydrating GF cement. The admixture of Al(OH)3in hydrating GF cement results in formation of a hydrogarnet having thecomposition Ca3Al2(SiO4).(OH)8.According to the results of the standard test "Determination of Resistanceto Deformation under Load at High Temperatures" (CSN ISO 1893), thebehaviour of the modified GF cement is comparable to the properties of aluminacement with a lower content of Al2O3.
