# US 8,323,782 B2 · Stratified cementitious composite > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,323,782 B2 - Document ID: US8323782B2 - Status: Granted - Kind: B2 - Application number: 12/520,846 - Filed: 2007-12-14 - Published: 2010-06-10 - Granted: 2012-12-04 - Earliest claimed: 2006-12-20 - Inventors: Larry Arthur Bellamy; Leonard George McSaveney; James Ronald Mackechnie - Web page: https://patentgrep.com/patent/US8323782B2 ## CPC - B28B 23/0081: {Embedding aggregates to obtain particular properties} - C04B 28/006: {containing mineral polymers, e.g. geopolymers of the Davidovits type} - C04B 28/02: containing hydraulic cements other than calcium sulfates - Y02P 40/10: Production of cement, e.g. improving or optimising the production methods; Cement grinding - Y02W 30/91: Use of waste materials as fillers for mortars or concrete - Y10T 428/2495: Thickness [relative or absolute] - Y10T 428/24992: Density or compression of components - Y10T 428/249971: Preformed hollow element-containing - Y10T 428/249973: Mineral element - Y10T 428/249974: Metal- or silicon-containing element - B28B: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER (foundry moulding B22C; working stone or stone-like material B28D; shaping of substances in a plastic state, in general B29C; making layered products not composed wholly of these substances B32B) - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention relates to a method for forming a stratified cementitious body comprising placing a cementitious slurry comprising a cementitious binder, to form the body in a single pour and curing the slurry to form a stratified cementitious body. The method may also comprise the steps of mixing a cementitious binder and at least one aggregate material with water to form a slurry, pouring the slurry into a mold, allowing the slurry to stratify into layers under the influence of gravitational forces and/or buoyancy forces, optionally applying vibrations to the slurry to encourage the slurry to stratify into layers, and curing the slurry to form a stratified cementitious body. ## Claims ### Claim 1 A stratified cementitious body formed in a single pour from a cementitious slurry comprising a cementitious binder, the slurry having: a yield shear stress of less than about 300 Pa, and a plastic viscosity of less than about 70 Pa·s, wherein the cementitious slurry comprises a more dense and a less dense aggregate material mixed with the cementitious binder and water. ### Claim 2 (depends on 1) The cementitious body as claimed in claim 1, wherein the more dense aggregate material is selected from the group consisting of slag, greywacke, basalt and steel fibers. ### Claim 3 (depends on 1) The cementitious body as claimed in claim 1, wherein the less dense aggregate material is selected from the group consisting of expanded glass, pumice, perlite, vermiculite, polystyrene, stabilised foam and plastic fibers. ### Claim 4 (depends on 1) The cementitious body as claimed in claim 1, formed from the cementitious slurry that has stratified into layers under the influence of gravitational forces and buoyancy forces. ### Claim 5 (depends on 1) The cementitious body as claimed in claim 1, formed from the cementitious slurry that has stratified into layers under the influence of gravitational forces which urged the more dense aggregate material to settle to the bottom of the slurry. ### Claim 6 (depends on 1) The cementitious body as claimed in claim 1, formed from the cementitious slurry that has stratified into layers under the influence of buoyancy forces which urged the less dense aggregate material to migrate to the top of the slurry. ### Claim 7 (depends on 1) The cementitious body as claimed in claim 1, formed from the cementitious slurry which has stratified into layers by control of the yield shear stress and plastic viscosity of the cementitious slurry. ### Claim 8 (depends on 1) The cementitious body as claimed in claim 1, wherein the composition of each of the layers of the cementitious body are formed by layers of stratified slurry, which have compositions that are substantially homogeneous. ### Claim 9 (depends on 1) The cementitious body as claimed in claim 1, wherein the more dense aggregate material has a relative density greater than 2.75. ### Claim 10 (depends on 1) The cementitious body as claimed in claim 1, wherein the more dense aggregate material forms a structural layer. ### Claim 11 (depends on 1) The cementitious body as claimed in claim 1, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is between about 12:1 to about 8:1. ### Claim 12 (depends on 1) The cementitious body as claimed in claim 1, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is between about 2:1 to about 7:1. ### Claim 13 (depends on 1) The cementitious body as claimed in claim 1, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is about 10:1. ### Claim 14 (depends on 1) The cementitious body as claimed in claim 1, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is about 4:1. ### Claim 15 (depends on 1) The cementitious body as claimed in claim 1, wherein the yield shear stress of the slurry is less than about 150 Pa. ### Claim 16 (depends on 1) The cementitious body as claimed in claim 1, wherein the yield shear stress of the slurry is less than about 100 Pa. ### Claim 17 (depends on 1) The cementitious body as claimed in claim 1, wherein the yield shear stress of the slurry is less than about 75 Pa. ### Claim 18 (depends on 1) The cementitious body as claimed in claim 1, wherein the yield shear stress of the slurry is less than about 50 Pa. ### Claim 19 (depends on 1) The cementitious body as claimed in claim 1, wherein the plastic viscosity of the slurry is between about 8 Pa·s. to about 30 Pa·s. ### Claim 20 (depends on 1) The cementitious body as claimed in claim 1, wherein the plastic viscosity of the slurry is between about 8 Pa·s. to about 25 Pa·s. ### Claim 21 (depends on 1) The cementitious body as claimed in claim 1, wherein the plastic viscosity of the slurry is between about 8 Pa·s. to about 15 Pa·s. ### Claim 22 (depends on 1) The cementitious body as claimed in claim 1, formed from a cementitious slurry that was substantially homogeneous prior to the step of allowing the mixture to stratify. ### Claim 23 (depends on 1) The cementitious body as claimed in claim 1, wherein the cementitious body is a multi-layered stratified cementitious body. ### Claim 24 (depends on 1) The cementitious body as claimed in claim 1, wherein the cementitious binder of the slurry comprises or includes an inorganic polymer binder. ### Claim 25 (depends on 1) The cementitious body as claimed in claim 1, wherein said cementitious body is a cured stratified cementitious panel comprising: a more dense aggregate material layer forming about one third of the overall thickness of the panel and a less dense aggregate material layer forming about two thirds of the overall thickness of the panel, the stratified cementitious panel having been formed from a slurry in a single pour, said slurry comprising a cementitious binder, the more dense aggregate material, the less dense aggregate material and water. ### Claim 26 (depends on 25) The cured stratified cementitious panel as claimed in claim 25, wherein the body is stratified into at least two layers, wherein the layers are substantially homogeneous. ### Claim 27 (depends on 26) The cured stratified cementitious panel as claimed in claim 26, wherein the composition of each of the at least two layers is substantially homogeneous. ### Claim 28 (depends on 25) The cured stratified cementitious panel as claimed in claim 25, wherein the aggregate material has a relative density greater than 2.75. ### Claim 29 (depends on 25) The cured stratified cementitious panel as claimed in claim 25, wherein the more dense aggregate material forms a structural layer. ### Claim 30 (depends on 25) The cured stratified cementitious panel as claimed in claim 25, wherein the less dense aggregate material forms an insulating layer. ### Claim 31 (depends on 1) A method for forming a stratified cementitious body according to claim 1 comprising placing into a mold the cementitious slurry to form the body in a single pour and curing the slurry to form a stratified cementitious body. ### Claim 32 (depends on 31) The method of claim 31 further comprising the steps of: (i) mixing the cementitious binder and aggregate materials with water to form said slurry, (ii) allowing the slurry to stratify into layers in said mold under the influence of gravitational forces and/or buoyancy forces, and (iii) optionally applying vibrations to the slurry to encourage the slurry to stratify into layers. ### Claim 33 (depends on 32) The method as claimed in claim 32, wherein the slurry is substantially homogeneous prior to the step of allowing the slurry to stratify. ### Claim 34 (depends on 32) The method as claimed in claim 32, wherein upon application of vibrations to the slurry the slurry stratifies into layers in less than 1 minute. ### Claim 35 (depends on 32) The method as claimed in claim 32, wherein vibrations are applied to the slurry for about 30 seconds at a vibrational frequency of about 2500 rpm. ### Claim 36 (depends on 31) The method as claimed in claim 31, wherein the more dense aggregate material is selected from the group consisting of slag, greywacke, basalt and steel fibers. ### Claim 37 (depends on 31) The method as claimed in claim 31, wherein the less dense aggregate material is selected from the group consisting of expanded glass, pumice, perlite, vermiculite, polystyrene, stabilized foam and plastic fibers. ### Claim 38 (depends on 31) The method as claimed in claim 31, wherein the slurry is formed so that it stratifies into layers under the influence of gravitational forces and buoyancy forces. ### Claim 39 (depends on 31) The method as claimed in claim 31, wherein the slurry is formed so that it stratifies into layers under the influence of gravitational forces urging the more dense aggregate material to settle to the bottom of the slurry. ### Claim 40 (depends on 31) The method as claimed in claim 31, wherein the slurry is formed so that it stratifies into layers under the influence of buoyancy forces urging the less dense aggregate material to migrate to the top of the slurry. ### Claim 41 (depends on 31) The method as claimed in claim 31, wherein the yield shear stress and plastic viscosity of the slurry are controlled to cause the slurry to stratify into layers. ### Claim 42 (depends on 31) The method as claimed in claim 31, wherein layers of the stratified slurry are substantially homogeneous. ### Claim 43 (depends on 31) The method as claimed in claim 31, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is between about 12:1 to about 8:1. ### Claim 44 (depends on 31) The method as claimed in claim 31, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is between about 2:1 to about 7:1. ### Claim 45 (depends on 31) The method as claimed in claim 31, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is about 10:1. ### Claim 46 (depends on 31) The method as claimed in claim 31, wherein a ratio of the relative densities of the more dense aggregate material to the less dense aggregate material is about 4:1. ### Claim 47 (depends on 31) The method as claimed in claim 31, wherein the yield shear stress of the slurry is less than about 150 Pa. ### Claim 48 (depends on 31) The method as claimed in claim 31, wherein the yield shear stress of the slurry is less than about 100 Pa. ### Claim 49 (depends on 31) The method as claimed in claim 31 wherein the yield shear stress of the slurry is less than about 75 Pa. ### Claim 50 (depends on 31) The method as claimed in claim 31, wherein the yield shear stress of the slurry is less than about 50 Pa. ### Claim 51 (depends on 31) The method as claimed in claim 31, wherein the plastic viscosity of the slurry is between about 8 Pa·s to about 30 Pa·s. ### Claim 52 (depends on 31) The method as claimed in claim 31, wherein the plastic viscosity of the slurry is between about 8 Pa·s. to about 25 Pa·s. ### Claim 53 (depends on 31) The method as claimed in claim 31, wherein the plastic viscosity of the slurry is between about 8 Pa·s. to about 15 Pa·s. ### Claim 54 (depends on 31) The method as claimed in claim 31, wherein the slurry or cementitious binder comprises or includes an inorganic polymer binder. ### Claim 55 (depends on 54) The method as claimed in claim 54, wherein the slurry is vibrated for about 60 seconds at 2500 rpm. ### Claim 56 (depends on 31) The method as claimed in claim 31, wherein the method is repeated to form a multi-layered stratified cementitious body.