Claims
- 1. A method for production of high strength structural building components, comprising preparing a moldable mixture of lime, laterite and water, the laterite comprising laterite particles containing iron oxide and silicon and aluminum, in the form of oxides and/or silicates thereof, and containing at least 8 weight percent of aluminum calculated as Al.sub.2 O.sub.3 and at least 4 weight percent of Fe.sub.2 O.sub.3, and the silicon content of the laterite including from 10 to 50 percent of quartz sand based on the weight of the laterite, the laterite comprising from 55 to 93 weight percent, the line from 5 to 15 weight percent and the water from 10 to 20 weight percent of the moldable mixture, the moldable mixture having the consistency of a free flowing mass, forming the components by pressure molding the mixture in a mold to form components which are sufficiently coherent to withstand transport, handling and stacking without damage, the pressure applied to the mixture being sufficient to provide a density in said components of 2000 to 2200 kg/m.sup.3, transporting the components to a curing station comprising an enclosure having a moisture saturated environment at atmospheric pressure and curing the pressure molded components at atmospheric pressure in said moisture saturated environment at a temperature between 70.degree. C and 100.degree. C, the curing being continued until the components attain a compressive strength of at least 140 kg/cm.sup.2 and a lime (as CaO) content of less than one or two percent.
- 2. A method for production of structural building components, comprising preparing a moldable mixture of lime, laterite and water, the laterite comprising laterite particles containing iron oxide and silicon and aluminum, in the form of oxides and/or silicates thereof, forming the building components from said mixture by applying pressure to said mixture in an amount sufficient to provide a density in said components of 2000 to 2200 kg/m.sup.3, the laterite comprising from 55 to 93 weight percent and the lime from 5 to 15 weight percent of the moldable mixture and the quantity of water being sufficient to yield pressure formed components which are sufficiently coherent and shape retaining to withstand transport, handling and stacking without damage, transporting the components to a curing station, and at said station curing the pressure formed components at atmospheric pressure in a moisture saturated environment and at a temperature of from 60.degree. C to 100.degree. C, the curing being continued until the components have a compressive strength of at least 140 kg/cm.sup.2 and a lime (as CaO) content of less than one or two percent.
- 3. A method according to claim 2 wherein the silicon content of the laterite includes from 10 to 50 percent of quartz sand based on the weight of the laterite.
- 4. A method according to claim 3 in which the moldable mixture constitutes a free flowing mass of particles and in which the pressure forming of the components is effected in a pressure mold.
- 5. A method according to claim 2 in which the laterite contains at least 8 weight percent of aluminum calculated as Al.sub.2 O.sub.3 and at least 4 weight percent of Fe.sub.2 O.sub.3.
- 6. A method according to claim 2 wherein the selected lateritic composition has a grain size distribution less than 2mm maximum size.
- 7. A method according to claim 2 wherein said mixture comprises up to 20 weight percent water.
- 8. A method according to claim 7 wherein said mixture comprises by weight about 3/4 laterite, and the balance about 1/2 lime calculated as CaO and about 1/2 water.
- 9. A method according to claim 2 wherein the curing is effected in an enclosure formed of sheet material and in which the heating of the component is effected at least in part by exposing the enclosure with the component therein to solar heat.
- 10. A method according to claim 2 wherein the curing temperature is between 70.degree. C and 100.degree. C.
- 11. A method according to claim 2 wherein surface characteristics of the component are modified by applying a surface layer of resin material to at least one surface of the component.
- 12. A method according to claim 11 wherein the resin material is applied to the component before curing thereof.
- 13. A method according to claim 11 wherein the component is formed in a pressure mold and wherein the resin material is applied to the surface of the component from the mold wall while the component is in the mold.
- 14. A method according to claim 2 wherein reinforcement fibers are distributed in the moldable mixture in the presence of a quantity of water in excess of that desired at the time of curing the component and in which such excess of water is separated before curing.
- 15. A method according to claim 2 wherein a surfactant is added to the mixture before pressure forming the components.
- 16. A method according to claim 15 wherein the surfactant is anionic.
- 17. A method according to claim 1 wherein said components are cured at a temperature of at least about 97.degree. C.
- 18. A method according to claim 2 wherein said components are cured at a temperature of at least about 97.degree. C.
- 19. A method according to claim 10 wherein said components are cured at a temperature of at least about 97.degree. C.
- 20. A method according to claim 2 wherein the components are formed by pressure molding the moldable mixture in a mold and wherein prior to curing the pressure formed components, they are separated from the mold and thereafter the separated components are transported to the curing station.
- 21. A method according to claim 20 wherein the laterite contains at least about 8 weight percent of aluminum, calculated as Al.sub.2 O.sub.3, and at least about 4 weight percent of Fe.sub.2 O.sub.3 and wherein the silicon content of the laterite includes about 10 to about 50 weight percent of quartz sand based on the weight of the laterite and wherein the moldable mixture contains about 10 to 20 weight percent of water and wherein the separated components are cured at a temperature between about 70.degree. C and 100.degree. C.
- 22. A method according to claim 21 wherein a pressure of from about 50 kg/cm.sup.2 to about 500 kg/cm.sup.2 is employed to pressure mold the moldable mixture into the pressure formed components.
- 23. A method according to claim 22 wherein the separated components are cured at a temperature of at least about 97.degree. C.
- 24. A method according to claim 1 wherein the moldable mixture comprises 70 to 85% laterite, 5 to 15% lime as CaO and 10 to 15% water.
- 25. A method according to claim 2 wherein the moldable mixture comprises 70 to 85% laterite, 5 to 15% lime as CaO and 10 to 15% water.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7517/71 |
Mar 1971 |
UK |
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Parent Case Info
This is a continuation of application Ser. No. 290,260, filed Sept. 18, 1972, now abandoned, which is a continuation-in-part of our application Ser. No. 236,205, filed Mar. 20, 1972, now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (3)
Number |
Date |
Country |
46,430 |
Jul 1966 |
DL |
1,539,249 |
Sep 1968 |
FR |
22,714 |
Jan 1899 |
UK |
Non-Patent Literature Citations (1)
Entry |
Dictionary of Ceramics by A. E. Dodd, Philosophical Library, Inc., N.Y., 1964 pp. 21 & 162 relied on. |
Continuations (1)
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Number |
Date |
Country |
Parent |
290260 |
Sep 1972 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
236205 |
Mar 1972 |
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