Hydraulic binder based on calcium sulphate hemi:hydrate - contg. cement plus aluminium nitrate or calcium formate, for mfg. building components or panels with high bend strength

摘要

Binder mixt. consists of (i) CaSO4.1/2H2O(CSHH) contg. by wt. 2.5-3.5% portland cement PZ-55 or PZ-60 with a C3S content of min. 60% and a Blaine specific surface (OBL) of min. 5800 cm2/g; and (ii) 0.3-0.8% Al nitrate or Ca formate. The pref. mixt. consists of (i) CSHH contg. 3-3.5% PZ-55 with C3S content 65% and OBL min. 6000 cm2/g; and (ii) 0.5% Al nitrate or Ca formate. The mixt. may also contain 0.2% KNO2 and the Al(NO3)2 may be replaced by Al sulphate. Binder is pref. used in mfg. gypsum bricks or panels or sandwich type plaster boards. Building components can be made with high bend strength, suitable for internal or external walls, ceilings, moulded bricks or panels, with low sensitivity to water.