Gypsum building material with improved high-temperature resistance

5-6. (canceled)

The gypsum building material according to claim 6, wherein the gypsum building material comprises 1 to 2.5 wt.-% of the H-siloxane and 1 to 5 wt.-% of the amorphous silicon dioxide.

A method for producing a gypsum building board, wherein at least one slurry is produced in that at least stucco and water are mixed with one another, the slurry is formed into an endless strand of gypsum building board, which is then separated into the gypsum building boards and the gypsum building boards are dried, the method comprising producing the slurry, wherein H-siloxane and/or amorphous silicon dioxide are/is additionally used, and/or applying H-siloxane is applied to at least one surface of the endless strand of the gypsum building board or of the separated gypsum building boards, such that the gypsum building board under an effect of temperature of at least 80° C. has a longer expansion phase than another gypsum building board without the H-siloxane and/or the amorphous silicon dioxide, wherein the other gypsum building board is otherwise of an identical composition.

A method to reduce the degree of shrinkage of a gypsum building material under an effect of temperature, the method comprising the step of adding an H-siloxane and/or an amorphous silicon dioxide to said gypsum building material, wherein the gypsum building material in accordance with a temperature/time curve according to DIN EN 1363-1:

• 2012-10 is heated from 0 to 60 min to 950° C. and is treated from 60 to 120 min with a constant temperature application of 950° C., and wherein the gypsum building material has a longer expansion phase and/or a smaller degree of shrinkage as compared to another gypsum building material without the H-siloxane and/or the amorphous silicon dioxide but of otherwise identical composition.