Cementitious flooring composition containing mixture of intermeshing particles of substantially spherical quartz sand

• US 4,108,813 A
• Filed: 12/17/1973
• Issued: 08/22/1978
• Est. Priority Date: 12/17/1973
• Status: Expired due to Term

• Current Assignee: Albert Lee Roberts
• Original Assignee: Albert Lee Roberts
• Inventors: Roberts, Albert Lee
• Primary Examiner(s): Anderson, Harold D.
• Application Number:
  US05/425,274
• Time in Patent Office: 1,709 Days
• Field of Search: 260/29.6 S
• US Class Current: 524/5
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 16/04 Macromolecular compounds C04B16/02 takes precedence
• CPC Class Codes: C04B 20/0076 characterised by the grain distribution
• CPC Class Codes: C04B 2111/00482 Coating or impregnation materials
• CPC Class Codes: C04B 2111/62 Self-levelling compositions
• CPC Class Codes: C04B 24/24 Macromolecular compounds C04B24/14 takes precedence; macromolecular compounds comprising sulfonate or sulfate groups C04B24/16
• CPC Class Codes: C04B 24/28 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds C04B24/243 takes precedence
• CPC Class Codes: C04B 28/04 Portland cements

Abstract

A cementitious composition suitable for spray application in formation of a dense floor structure. The composition has a Brookfield viscosity of about 2,000 to about 5,000 centipoises (cps) as measured at 20 rpm with a number 3 spindle and contains about 58 to about 70 percent by weight of a mixture of intermeshing particles of substantially spherical quartz sand. The intermeshing particles of substantially spherical quartz sand are composed of a weight fraction of relatively large size particles and a weight fraction of relatively small size particles with the weight ratio of the larger particles to the smaller particles ranging from about 3:1 to about 1:1 and an average diameter ratio of the larger particles with respect to the smaller particles ranging from about 2:1 to about 3:1. Additionally, the composition has a low water-to-cement ratio of about 0.4 to about 0.5 and contains a plastic-in-water emulsion composed of minute spherical plastic particles which intermesh with the particles of substantially spherical quartz to provide a dense floor structure having a low content of voids. The emulsion has a solids content of about 20 percent to about 50 percent by weight and, in addition, the composition contains a flow control material such as a high molecular weight poly(ethylene oxide) and optionally a gel retarder. The flow control material is present in an amount sufficient to provide the composition with laminar flow properties during spraying while the gel retarder may be present in an amount sufficient to provide a gel time between about 1 hour and about 6 hours.

A method for forming a relatively dense cementitious floor structure which has a relatively low percentage of voids and very little shrinkage during curing, which comprises spraying the above described composition through a nozzle onto a generally horizontal supporting surface.

Claims

1. A cementitious composition suitable for spray application in the formation of a dense floor structure, said composition consisting essentially of:

about 58 to about 70 percent by weight of a mixture of intermeshing particles of substantially spherical quartz sand;

said mixture including a weight fraction of relatively large size particles and a weight fraction of relatively small size particles;

the weight ratio of the relatively large size particles with respect to the relatively small size particles ranging from about 3;

1 to about 1;

1 and the ratio of the average diameter of the relatively large size particles with respect to the average diameter of the relatively small size particles ranging from about 2;

1 to about 3;

1;

a finely ground Portland cement;

a plastic-in-water emulsion having a solids content of about 20 to about 50 percent by weight of the emulsion;

the plastic in sand emulsion being an acrylic plastic which is present in the form of minute spherical particles having a particle size of about 0.05 to about 50 microns and said plastic being capable of forming a tacky film at ambient temperatures and bonding to the substantially spherical quartz sand;

a flow control material in an amount sufficient to provide the composition with laminar flow properties during spray application;

said composition having a low water-to-cement ratio in the range of about 0.4 to about 0.5, with the water being furnished by said emulsion and

said composition having a Brookfield viscosity of about 2,000 to about 5,000 centipoisers as measured at 20 rpm with a Brookfield Synchroelectric Viscometer, Model LVF, using a number 3 spindle,

whereby said composition may be sprayed onto a generally horizontal support surface in the formation of a dense floor structure having a low void content and being substantially free from surface cracking or crazing and with the composition being sufficiently fluid to provide flow and leveling after application to the support surface.

2. The composition of claim 1 wherein

the quartz sand in the weight fraction of relatively large size particles has an average particle size which does not exceed about 20 mesh, and

the quartz sand in the weight fraction of relatively small size particles has an average particle size which is not less than about 87 mesh.

3. The cementitious composition of claim 2 wherein said water-to-cement ratio is about 0.45 to about 0.47.

4. The composition of claim 2 including a small quantity of gel retarder in an amount sufficient to provide a gel time for said composition of about 1 to about 6 hours while decreasing the gel size of said composition.

5. The composition of claim 2 wherein

the quartz sand in the weight fraction of relatively large size particles has an average particle size of about 27 mesh, and

the quartz sand in the weight fraction of relatively small size particles has an average particle size of about 87 mesh.

6. The composition of claim 2 wherein said flow control material is a high molecular weight poly(ethylene oxide) resin.

7. The composition of claim 2 wherein

said Portland cement is a general purpose Portland cement, and

the content of said Portland cement is about 20 to about 23 percent by weight of the composition.

8. The composition of claim 1 wherein the acrylic plastic in said emulsion is present in the form of minute spherical particles having a particle size of about 0.1 to about 10 microns.

9. The composition of claim 8 wherein the solids content of said emulsion is about 32 to about 40 percent by weight of said emulsion.

10. The composition of claim 8 wherein the viscosity of said composition is about 2,000 to about 3,000 centipoises as measured at 20 rpm with a Brookfield Synchroelectric Viscometer, Model LVF, using a number 3 spindle.

11. The composition of claim 2 wherein said mixture of substantially spherical quartz sand is present in an amount of about 63 to about 65 percent by weight of the composition.

12. The composition of claim 5 wherein said mixture of substantially spherical quartz sand is present in an amount of about 63 to about 65 percent by weight of the composition.

13. The composition of claim 12 wherein

the quartz sand in the weight fraction of relatively large size particles is present in an amount of about 45 to about 48 percent, and

the quartz sand in the weight fraction of relatively small size particles is present in an amount of about 15 to about 19 percent by weight.

14. A cementitious composition suitable for spray application in the formation of a dense floor structure, said composition consisting essentially of:

about 63 to about 65 percent by weight of a mixture of intermeshing particles of substantially spherical quartz sand;

said mixture including a weight fraction of relatively large size particles and a weight fraction of relatively small size particles;

the quartz sand in the weight fraction of relatively large size particles having an average particle size of about 27 mesh and being present in an amount of about 45 to about 48 percent;

the quartz sand in the weight fraction of relatively small size particles having an average particle size of about 87 mesh and being present in an amount of about 15 to about 19 percent;

a finely divided Portland cement;

a plastic-in-water emulsion having a solids content of about 32 to about 40 percent by weight;

said plastic being present in the emulsion in the form of minute spheres having a particle size of about 0.1 to about 10 microns;

said plastic being an acrylic plastic which is capable of forming a tacky film at ambient temperatures in bonding to the intermeshing particles of substantially spherical quartz sand through coalescence of the minute plastic spherical particles;

a poly(ethylene oxide) flow control material at a concentration of about 0.001 to about 0.002 percent by weight sufficient to provide the composition with laminar flow characteristics during spray application;

said composition having a water-to-cement ratio in the range of about 0.45 to about 0.47, with the water being furnished by said emulsion and

said composition having a Brookfield viscosity of about 2,000 to about 3,000 centipoises as measured at 20 rpm with a Brookfield Synchroelectric Viscometer, Model LVF, using a number 3 spindle,

whereby said composition may be sprayed onto a generally horizontal support surface in the formation of a dense floor structure having a low void content and being substantially free from surface cracking or crazing and with the composition being sufficiently fluid to provide flow and leveling after application to the support surface.

15. The composition of claim 14 including a gel retarder in an amount sufficient to provide a gel time of about 1 to about 6 hours while decreasing the gel size of the composition.

16. The composition of claim 15 wherein said gel retarder is present at a concentration of about 0.02 to about 0.06 percent by weight.

17. The composition of claim 15 wherein said gel retarder is present at a concentration of about 0.03 to about 0.05 percent by weight.

18. The composition of claim 14 wherein

said Portland cement is a general purpose Portland cement, and

the content of said Portland cement is about 20 to about 23 percent by weight of the composition.

19. The composition of claim 17 wherein

said Portland cement is a general purpose Portland cement, and

the content of said Portland cement is about 20 to about 23 percent by weight of the composition.

20. The composition of claim 19 wherein the solids content of said plastic-in-water emulsion is about 35 percent by weight of the emulsion.