# US 2019/0169071 A1 · Low-density high-strength concrete and related methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169071 A1 - Document ID: US20190169071A1 - Status: Published application - Kind: A1 - Application number: 16/268,584 - Filed: 2019-02-06 - Published: 2019-06-06 - Earliest claimed: 2014-03-09 - Assignees: Sebastos Technologies Inc. - Applicants: Sebastos Technologies Inc. - Inventors: Randall L. Byrd; Matthew D'ambrosia - Web page: https://patentgrep.com/patent/US20190169071A1 ## CPC - C04B 28/04: Portland cements - B28C 7/022: {by measuring the consistency or composition of the mixture, e.g. with supply of a missing component} - B28C 7/024: {by measuring properties of the mixture, e.g. moisture, electrical resistivity, density} - C04B 14/24: porous, e.g. foamed glass - C04B 18/027: {Lightweight materials} - C04B 28/02: containing hydraulic cements other than calcium sulfates - C04B 2103/44: Thickening, gelling or viscosity increasing agents - C04B 2103/58: {Shrinkage reducing agents} - C04B 2111/00103: {Self-compacting mixtures} - C04B 2111/40: Porous or lightweight materials - Y02W 30/91: Use of waste materials as fillers for mortars or concrete - 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 - B28C: PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER (preparing material for foundry moulds B22C5/00) - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract A low-density, high-strength concrete composition that is both self-compacting and lightweight, with a low weight-fraction of aggregate to total dry raw materials, and a highly-homogenous distribution of a non-absorptive and closed-cell lightweight aggregate such as glass microspheres or copolymer polymer beads or a combination thereof, and the steps of providing the composition or components. Lightweight concretes formed therefrom have low density, high strength-to-weight ratios, and high R-value. The concrete has strength similar to that ordinarily found in structural lightweight concrete but at an oven-dried density as low as 40 lbs./cu.ft. The concrete, at the density ordinarily found in structural lightweight concrete, has a higher strength and, at the strength ordinarily found in structural lightweight concrete, a lower density. Such strength-to-density ratios range approximately from above 30 cu.ft/sq.in. to above 110 cu.ft/sq.in., with a 28-day compressive strength ranging from about 3400 to 8000 psi. ## Claims ### Claim 1 A lightweight concrete composition comprising: one or more cementitious materials; an aggregate mix composed of individual particles that are substantially volumetrically stable and non-absorbent; said aggregate mix comprising hollow glass microspheres; a de-air entrainer; a shrinkage reducer; and a viscosity modifier; wherein the lightweight concrete composition has a compressive strength after 28 days as measured by ASTM C39 of at least about 1750 psi. ### Claim 2 (depends on 1) The lightweight concrete composition of claim 1, wherein the shrinkage reducer comprises calcium oxide, calcium sulfo-aluminate, or any combination of any of the foregoing. ### Claim 3 (depends on 1) The lightweight concrete composition of claim 1, wherein the de-air entrainer is present in an amount of about 8.5 to 14.2 oz. per 100 lbs. of cementitious materials. ### Claim 4 (depends on 1) The lightweight concrete composition of claim 1, wherein the concrete composition has an oven-dried density of about 36 to about 55 lb/ft3, and a compressive strength after 28 days as measured by ASTM C39 of at least about 2500 psi. ### Claim 5 (depends on 1) The lightweight concrete composition of claim 1, wherein said glass microspheres have a specific gravity of about 0.15, and said glass microspheres have a 90% survival rate at a pressure of about 300 psi. ### Claim 6 The lightweight concrete composition of claim i, wherein the concrete composition has a compressive strength-to-density ratio of about 71.2 to about 97.1, where the compressive strength is measured in psi according to ASTM C39 after 28 days and the density is measured in lb/ft3 according to ASTM C567. ### Claim 7 A lightweight concrete composition comprising: one or more cementitious materials; an aggregate mix composed of individual particles that are substantially volumetrically stable and non-absorbent; said aggregate mix comprising hollow glass microspheres; a de-air entrainer; and a viscosity modifier; wherein the lightweight concrete composition has a compressive strength after 28 days as measured by ASTM C39 of at least about 2500 psi. ### Claim 8 (depends on 7) The lightweight concrete composition of claim 7, further comprising a shrinkage reducer. ### Claim 9 (depends on 8) The lightweight concrete composition of claim 8, wherein the shrinkage reducer comprises calcium oxide, calcium sulfo-aluminate, or any combination of any of the foregoing. ### Claim 10 (depends on 7) The lightweight concrete composition of claim 7, wherein the concrete has a ring test score, as measured by ASTM C1581, of about 10.1 to 16.2. ### Claim 11 (depends on 7) The lightweight concrete composition of claim 7, wherein the compressive strength after 28 days as measured by ASTM C39 of at least about 3800 psi. ### Claim 12 (depends on 7) The lightweight concrete composition of claim 7, wherein the concrete composition has a compressive strength-to-density ratio of about 29.8 to about 62.5, where the compressive strength is measured in psi according to ASTM C39 after 7 days and the density is measured in lb/ft3 according to ASTM C567. ### Claim 13 (depends on 12) The lightweight concrete composition of claim 12, further comprising gravel. ### Claim 14 (depends on 7) The lightweight concrete composition of claim 7, wherein the concrete composition has (i) a compressive strength-to-density ratio of about 48.5 to about 97.1, where the compressive strength is measured in psi according, to ASTM C39 after 28 days and the density is measured in lb/ft3 according to ASTM C567, and (ii) an oven-dried density of about 36 to about 55 lb/ft3. ### Claim 15 (depends on 7) The lightweight concrete composition of claim 7, wherein the concrete composition has an oven-dried density of about 36 to about 55 lb/ft3. ### Claim 16 (depends on 7) The lightweight concrete composition of claim 7, wherein the concrete composition has a compressive strength-to-density ratio of about 40.3 to about 62.5, where the compressive strength is measured in psi according to ASTM C39 after 7 days and the density is measured in lb/ft3 according to ASTM C567. ### Claim 17 (depends on 7) The lightweight concrete composition of claim 7, wherein the concrete composition has a compressive strength-to-density ratio of about 71.2 to about 97.1, where the compressive strength is measured in psi according to ASTM C39 after 28 days and the density is measured in lb/ft3 according to ASTM C567. ### Claim 18 (depends on 7) The lightweight concrete composition of claim 7, wherein the de-air entrainer is present in an amount of about 6 to 10 oz. per 100 lbs. of cementitious materials. ### Claim 19 (depends on 7) The lightweight concrete composition of claim 7, wherein the de-air entrainer is present in an amount of about 8.5 to 14.2 oz. per 100 lbs. of cementitious materials. ### Claim 20 A method for preparing a lightweight concrete composition comprising the steps of: (a) obtaining a cementitious mixture comprising (i) one or more cementitious materials, (ii) water, (iii) an aggregate mix composed of individual particles that are substantially volumetrically stable and non-absorbent to the mixer, said aggregate mix comprising hollow glass microspheres, and (iv) a viscosity modifier to inhibit segregation of the glass microspheres within the mixture; (b) reducing the amount of air entrained within the cementitious mixture by adding a de-air entrainer; and (c) curing the cementitious mixture. ### Claim 21 (depends on 20) The method of claim 20, wherein said hollow glass microspheres remain largely unsegregated in said cementitious mixture prior to curing. ### Claim 22 (depends on 20) The method of claim 20, wherein step (b) comprises adding a sufficient amount of de-air entrainer to achieve a plastic air content within the cementitious mixture of between about 2% and 7%. ### Claim 23 (depends on 20) The method of claim 20, wherein, prior to curing, the cementitious mixture has a target plastic density of not more than about 100 lb./ft3. ### Claim 24 (depends on 20) The method of claim 20, further comprising the step of increasing the resistance of the cementitious mixture to cracking during curing by adding a shrinkage reducer to the cementitious material prior to curing. ### Claim 25 (depends on 20) The method of claim 20, wherein said cured lightweight concrete has a compressive strength after 28 days as measured by ASTM C39 of at least about 2500 psi.