Abstract: In a process for the manufacture of composite material comprising a matrix of set inorganic binder (e.g. Portland cement) and reinforcing fibre (e.g. carbon fibre), by de-watering a slurry containing water-settable inorganic binder, reinforcing fibre and web-forming fibre (e.g. cellulose fibre), and subsequently setting the binder, a ball clay is included in the slurry that is de-watered, in order to reduce shrinkage of the composite material during setting of the binder.

Abstract: A board product containing glassy inorganic fibre such as mineral wool, in a matrix of a plastic clay such as ball clay. The amounts of clay and inorganic fibre are in the respective ranges 29 to 80 percent by weight and 15 to 55 percent by weight of the product, and its density is at least 500 kg/m.sup.3.The board can replace asbestos millboard and has the advantage of being asbestos-free. It can be made by the standard paper and board-making techniques, when preferred ingredients are pulp fibres e.g. cellulose pulp, and a complementary binder, particularly hydrolyzable starch, the latter enabling the product to be re-mouldable upon moistening with water.

Abstract: Glass compositions consisting essentially of an E-glass are modified by incorporation therein of zirconia or of zirconia and titania, preferably in a total amount not exceeding 12%, more preferably not exceeding 8%, by weight of the composition, whereby significant improvement in alkali resistance is achieved.

Abstract: Glass compositions, having improved chemical resistance and useful in the form of fibers for reinforcing cementitious materials, consisting essentially of:From 50 to 75 percent by weight SilicaFrom 10 to 25 percent by weight R.sub.2 Ofrom .[.1.]. .Iadd.7 .Iaddend.to 15 percent TitaniaFrom 1 to 20 percent by weight ZirconiaFrom 0.8 to 20 percent by weight Rare Earth OxideFrom 0 to 20 percent by weight Boric OxideFrom 0 to 10 percent by weight R.sup.1 Ofrom 0 to 1 percent by weight Fluorine as (fluoride)From 0 to 2 percent by weight Al.sub.2 O.sub.3from 0 to 1 percent by weight P.sub.2 O.sub.5from 0 to 1 percent by weight Chlorine (as chloride)Where R.sub.2 O is sodium oxide, potassium oxide or a mixture of both, optionally including up to 5% by weight of lithium oxide (based on the total composition) and R.sup.1 O is MgO, CaO, BaO, or SrO, or a mixture of two or more thereof.