Abstract In a building material comprising an inorganic binder selected from the group consisting of Portland cement, alumina cement, calcium silicate, lime and gypsum, structurally reinforced with glass fibers, the improvement which comprises employing as said glass fibers alkali-resistant calcium silicate glass fibers consisting essentially of approximately ______________________________________ CaO 26 - 50 % by weight
SiO 2 40 - 65
Al 2 O 3 1 - 8
ZnO+ZrO 2 +Cr 2 O 3 0.1 - 10
Fe 2 O 3 and Na 2 O
< 2.
______________________________________
In a building material comprising an inorganic binder selected from the group consisting of Portland cement, alumina cement, calcium silicate, lime and gypsum, structurally reinforced with glass fibers, the improvement which comprises employing as said glass fibers alkali-resistant calcium silicate glass fibers containing at least one modifying oxide selected from the group consisting of ZnO, ZrO 2 and Cr 2 O 3 said fibers consisting essentially of approximately ______________________________________
CaO 26 - 50 % by weight
SiO.sub.2 40 - 65 %
Al.sub.2 O.sub.3 1 - 8
ZnO+ZrO.sub.2 +CrO.sub.3
0.1 - 10
Fe.sub.2 O.sub.3 and Na.sub.2 O
< 2
______________________________________
Claim 2
Dependent Claim
99 words
In a building material comprising an inorganic binder selected from the group consisting of Portland cement, alumina cement, calcium silicate, lime and gypsum, structurally reinforced with glass fibers, the improvement which comprises employing as said glass fibers alkali-resistant calcium silicate glass fibers containing at least one modifying oxide selected from the group consisting of ZnO, ZrO 2 and Cr 2 O 3 said fibers consisting essentially of approximately ______________________________________
CaO 26 - 50 % by weight
SiO.sub.2 40 - 65 %
Al.sub.2 O.sub.3 1 - 8
ZnO+ZrO.sub.2 +CrO.sub.3
0.1 - 10
Fe.sub.2 O.sub.3 and Na.sub.2 O
< 2
______________________________________
Claim 3
Dependent Claim
31 words
A building material according to claim 1, wherein the content of ZnO + ZrO 2 + Cr 2 O 3 in the fiber is from about 2 to 7% by weight.
Claim 4
Dependent Claim
32 words
A building material according to claim 1, wherein an aqueous extract of the inorganic binder has a pH value approximately equal to that of an aqueous extract of the calcium silicate fiber.