High strength pourable gypsum floor underlayments and methods of providing same

Claim 3

The method of claim 1 wherein said hydraulic cement is Portland cement.

Claim 6

The method of claim 1 wherein said defoamer is selected from the group consisting of tributyl phosphate, silicones, borate esters, petroleum derivatives, and tert-butyl phthalates.

Claim 7

The method of claim 1 wherein said gypsum-based cementitious composition comprises about 12% to 15% of said hydraulic cement; about 84% to 86% of said calcium sulfate α-hemihydrate; about 0.6% to 0.65% of said superplasticizer; about 0.25% to 0.4% of said defoamer; and about 0.003% to 0.006% of said alkylcellulose.

Claim 8

A gypsum-based cementitious sub-floor having a dust-free surface and a compressive strength in the range of about 2500 to 6000 psi, made by a method comprising the steps of a) providing a gypsum-based cementitious composition consisting essentially of 1) from about 10% to 20%, by total weight of said gypsum-based cementitious composition, hydraulic cement; 2) from about 70% to 86%, by total weight of said gypsum-based cementitious composition, calcium sulfate α-hemihydrate; 3) from about 0.5% to 0.75%, by total weight of said gypsum-based cementitious composition, of a superplasticizer; 4) from about 0.2% to 0.5%, by total weight of said gypsum-based cementitious composition, of a defoamer; and 5) from about 0.002% to 0.01. %, by total weight of said gypsum-based cementitious composition, of an alkylcellulose; b) mixing said gypsum-based cementitious composition with sand, in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and sufficient water to provide a pumpable, self-leveling wet gypsum-based cementitious composition having a flowability such that when 600 ml of said wet gypsum-based cementitious composition is poured into a 15.2 cm×20.3 cm×1.9 cm tray at a height of 12.7 cm in one smooth motion, the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, and c) hardening said wet gypsum-based cementitious composition to provide a sub-floor resistant to dimensional changes caused during hardening and having a dust-free surface and a compressive strength in the range of about 2500 to 6000 psi.

Claim 9

A gypsum-based cementitious sub-floor having a dust-free surface and a compressive strength in the range of about 2500 to 6000 psi, made by a method comprising the steps of a) providing a gypsum-based cementitious composition consisting essentially of 1) from about 10% to 20%, by total weight of said gypsum-based cementitious composition, hydraulic cement; 2) from about 70% to 86%, by total weight of said gypsum-based cementitious composition, calcium sulfate α-hemihydrate; 3) from about 0.5% to 0.75%, by total weight of said gypsum-based cementitious composition, of a superplasticizer; 4) from about 0.2% to 0.5%, by total weight of said gypsum-based cementitious composition, of a defoamer; and 5) from about 0.002% to 0.01. %, by total weight of said gypsum-based cementitious composition, of an alkylcellulose; b) mixing said gypsum-based cementitious composition with sand, in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and sufficient water to provide a pumpable, self-leveling wet gypsum-based cementitious composition having a flowability such that when 600 ml of said wet gypsum-based cementitious composition is poured into a 15.2 cm×20.3 cm×1.9 cm tray at a height of 12.7 cm in one smooth motion, the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, and c) hardening said wet gypsum-based cementitious composition to provide a sub-floor resistant to dimensional changes caused during hardening and having a dust-free surface and a compressive strength in the range of about 2500 to 6000 psi.

Claim 10

A gypsum-based cementitious composition capable of, upon mixing with sand in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and sufficient water to provide a pumpable, self-leveling wet gypsum-based cementitious composition having a flowability such that when 600 ml of said wet gypsum-based cementitious composition is poured into a 15.2 cm×20.3 cm×1.9 cm tray at a height of 12.7 cm in one smooth motion, the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, providing, upon hardening, a sub-floor resistant to dimensional changes caused during hardening and having a dust-free surface and compressive strength in the range of about 2500 to 6000 psi, said gypsum-based cementitious composition consisting essentially of a) from about 10% to 20%, by total weight of said gypsum-based cementitious composition, hydraulic cement; b) from about 70% to 90%, by total weight of said gypsum-based cementitious composition, calcium sulfate α-hemihydrate; c) from about 0.5% to 0.75%, by total weight of said gypsum-based cementitious composition, of a superplasticizer; d) from about 0.2% to 0.5%, by total weight of said gypsum-based cementitious composition, of a defoamer, and; e) from about 0.002% to 0.01%, by total weight of said gypsum-based cementitious composition, of an alkylcellulose.

Claim 11

A gypsum-based cementitious composition capable of, upon mixing with sand in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and sufficient water to provide a pumpable, self-leveling wet gypsum-based cementitious composition having a flowability such that when 600 ml of said wet gypsum-based cementitious composition is poured into a 15.2 cm×20.3 cm×1.9 cm tray at a height of 12.7 cm in one smooth motion, the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, providing, upon hardening, a sub-floor resistant to dimensional changes caused during hardening and having a dust-free surface and compressive strength in the range of about 2500 to 6000 psi, said gypsum-based cementitious composition consisting essentially of a) from about 10% to 20%, by total weight of said gypsum-based cementitious composition, hydraulic cement; b) from about 70% to 90%, by total weight of said gypsum-based cementitious composition, calcium sulfate α-hemihydrate; c) from about 0.5% to 0.75%, by total weight of said gypsum-based cementitious composition, of a superplasticizer; d) from about 0.2% to 0.5%, by total weight of said gypsum-based cementitious composition, of a defoamer, and; e) from about 0.002% to 0.01%, by total weight of said gypsum-based cementitious composition, of an alkylcellulose.

Claim 12

The composition of claim 8 wherein said hydraulic cement is Portland cement.

Claim 13

The composition of claim 8 wherein said hydraulic cement is a Type V Portland cement.

Claim 14

The composition of claim 8 wherein said superplasticizer is selected from the group consisting of naphthalene sulfonates; naphthalene sulfonate-formaldehyde condensates; calcium lignosulfonate; melamine sulfonate-formaldehyde condensates; and polycarboxylic acids.

Claim 15

The composition of claim 8 wherein said defoamer is selected from the group consisting of tributyl phosphate, silicones, borate esters, petroleum derivatives, and tert-butyl phthalates.

Claim 16

The composition of claim 8 wherein said gypsum-based cementitious composition comprises about 12% to 15% of said hydraulic cement; about 84% to 86% of said calcium sulfate a-hemihydrate; about 0.6% to 0.65% of said superplasticizer; about 0.25% to 0.4% of said defoamer; and about 0.003% to 0.006% of said alkylcellulose.

Claim 17

A wet gypsum-based cementitious composition having a flowability such that when 600 ml of said wet gypsum-based cementitious composition is poured into a 15.2 cm×20.3 cm×1.9 cm tray at a height of 2.7 cm in one smooth motion, the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, providing, upon hardening, a sub-floor resistant to dimensional changes caused during hardening and having a dust-free surface and compressive strength in the range of about 2500 to 6000 psi, said wet gypsum-based cementitious composition consisting essentially of a) from about 10% to 20%, by total weight of said gypsum-based cementitious composition, hydraulic cement; b) from about 70% to 86%, by total weight of said gypsum-based cementitious composition, calcium sulfate α-hemihydrate; c) from about 0.5% to 0.75%, by total weight of said gypsum-based cementitious composition, of a superplasticizer; d) from about 0.2% to 0.5%, by total weight of said gypsum-based cementitious composition, of a defoamer; and e) from about 0.002% to 0.01%, by total weight of said gypsum-based cementitious composition, of an alkylcellulose; f) sand, in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and g) sufficient water to provide said flowability.

Claim 18

A wet gypsum-based cementitious composition having a flowability such that when 600 ml of said wet gypsum-based cementitious composition is poured into a 15.2 cm×20.3 cm×1.9 cm tray at a height of 2.7 cm in one smooth motion, the wet gypsum-based cementitious composition completely self-levels to produce a topographically smooth surface without floating or finishing, providing, upon hardening, a sub-floor resistant to dimensional changes caused during hardening and having a dust-free surface and compressive strength in the range of about 2500 to 6000 psi, said wet gypsum-based cementitious composition consisting essentially of a) from about 10% to 20%, by total weight of said gypsum-based cementitious composition, hydraulic cement; b) from about 70% to 86%, by total weight of said gypsum-based cementitious composition, calcium sulfate α-hemihydrate; c) from about 0.5% to 0.75%, by total weight of said gypsum-based cementitious composition, of a superplasticizer; d) from about 0.2% to 0.5%, by total weight of said gypsum-based cementitious composition, of a defoamer; and e) from about 0.002% to 0.01%, by total weight of said gypsum-based cementitious composition, of an alkylcellulose; f) sand, in a weight ratio to said gypsum-based cementitious composition of from about 1.25:1 to 2.5:1; and g) sufficient water to provide said flowability.