Abstract: To reinforce products made from hydraulic binder agents, fibers of polymerized acrylic nitrile, which are manufactured with a molar concentration of acrylic nitrile units of at least 98%, are used. The fibers advantageously have a strength of at least 50 cN/tex and a breaking elongation of at most 15%. These fibers produce a product after setting having good bending tensile strength and excellent impact strength.

Abstract: Asbestos-free, fiber-reinforced, hydraulically setting compositions can be processed to fiber-reinforced shaped articles. The compositions are obtained by mixing fibers, hydraulic binders and water-soluble or water-emulsifiable polymers and by adding a metallic compound, particularly a metal salt or hydroxide. The composition can be processed in the equipment conventionally used in the asbestos cement industry.

Abstract: Asbestos-free fiber reinforced hydraulically setting materials, which comprise a slurry of one or more hydraulic binding agents, fibers, water and perhaps additional additives, are obtained when, as fiber, 2 to 20% by volume of filter fibers and 0,5 to 20, preferably 1 to 10% by volume reinforcing fibers are used, both of which are subjected to preliminary treatment which improves their dispersability. By means of the preliminary treatment the fibers can be uniformly distributed in the slurry. The material can be worked on apparatus common for the production of asbestos cement and used for the same purposes as asbestos cement.