Method For Manufacturing A Cementitious Composition

Abstract

A method of expanding expandable polymeric microspheres including contacting an aqueous slurry including unexpanded, expandable polymeric microspheres with steam in-situ during manufacture of a cementitious composition or article. A method of manufacturing a cementitious composition or article includes: (i) contacting an aqueous slurry of unexpanded, expandable polymeric microspheres with steam proximate to and/or during said manufacturing of the cementitious composition to create expanded polymeric microspheres; (ii) pre-wetting the expanded polymeric microspheres; and (iii) mixing the pre-wetted, expanded polymeric microspheres with cement and water to form the cementitious composition.

What is claimed is: 
     
         1 . A method of expanding expandable polymeric microspheres comprising contacting an aqueous slurry comprising unexpanded, expandable polymeric microspheres with steam proximate to and/or during manufacture of a cementitious composition. 
     
     
         2 . The method of  claim 1 , wherein the method comprises contacting an aqueous slurry with steam in-situ during manufacture of a cementitious composition. 
     
     
         3 . The method of  claim 2 , wherein said contacting the aqueous slurry with steam in-situ during manufacture of a cementitious composition comprises contacting the aqueous slurry with steam prior to introducing the aqueous slurry into a feed water stream being fed into a cementitious composition during manufacture of the cementitious composition. 
     
     
         4 . The method of  claim 3 , wherein the flow of the aqueous slurry into the feed water stream is restricted and/or controlled. 
     
     
         5 . The method of  claim 3 , wherein the feed water stream is fed into a cementitious composition mixing truck. 
     
     
         6 . The method of  claim 1 , wherein said contacting the aqueous slurry with steam proximate to and/or during manufacture of a cementitious composition comprises contacting the aqueous slurry with steam to expand the expandable polymeric microspheres and quenching the expanded expandable polymeric microspheres into water at a cementitious composition manufacturing facility, and reserving the aqueous slurry for introduction into a cementitious composition manufactured at the facility. 
     
     
         7 . The method of  claim 6 , wherein the aqueous slurry is reserved in a reserve tank. 
     
     
         8 . The method of  claim 6 , wherein prior to said quenching the expanded expandable polymeric microspheres into water, the flow of the aqueous slurry is restricted and/or controlled. 
     
     
         9 . A method of manufacturing a cementitious composition or cementitious article comprising the composition, the method comprising: (i) contacting an aqueous slurry of unexpanded, expandable polymeric microspheres with steam proximate to and/or during said manufacturing of the cementitious composition to create expanded polymeric microspheres; (ii) optionally pre-wetting the expanded polymeric microspheres; and (iii) incorporating the expanded polymeric microspheres into the cementitious composition. 
     
     
         10 . The method of  claim 9 , wherein the method comprises contacting an aqueous slurry with steam in-situ during manufacture of a cementitious composition. 
     
     
         11 . The method of  claim 9 , wherein said pre-wetting the expanded polymeric microspheres comprises dispersing the expanded polymeric microspheres in liquid, optionally wherein the liquid comprises water. 
     
     
         12 . The method of  claim 9 , wherein said pre-wetting the expanded polymeric microspheres comprises adding the expanded polymeric microspheres and a liquid to a mixing tank, optionally wherein the liquid comprises water. 
     
     
         13 . The method of  claim 12 , wherein the expanded polymeric microspheres comprise from about 1% to about 60% of the total volume of all material in the mixing tank. 
     
     
         14 . The method of  claim 9 , wherein after said contacting the aqueous slurry with steam, the flow of the aqueous slurry is restricted and/or controlled. 
     
     
         15 . The method of  claim 14 , wherein the flow of the aqueous slurry is restricted and/or controlled by a device which generates back pressure. 
     
     
         16 . The method of  claim 15 , wherein the device which generates back pressure is a valve or an orifice nozzle. 
     
     
         17 . The method of  claim 9 , further comprising retaining a dispersion of pre-wetted, expanded polymeric microspheres or a liquid admixture containing the pre-wetted, expanded polymeric microspheres in at least one of a plurality of reservoirs prior to introduction and mixing into the cementitious composition.