Building framing beams or studs composed of a cementitious material and method of making

Abstract

A cementitious material beam for use in the building construction industry and a method of fabricating such beam.

1 . A cementitious material building construction beam comprising:
 an elongated, rectangular, tubular hollow member;   a screen material encasing the tubular member;   a plurality of rectangular, relatively rigid plates having a central opening and at least four circular openings adjacent the corners of said plates, said plates disposed within said tubular member at longitudinally spaced apart locations;   high tensile strength rods, at least one for each plate corner opening, extending through the plate corner openings along the full length of the tubular member;   a cementitious mixture filling the tubular member, comprising cement, sand, water and a low density, expanded silicon dioxide material.   
   
   
       2 . The beam of  claim 1  additionally including an exterior thin layer of cementitious mixture applied to the outside of the tubular member so as to embed screen material within the mixture. 
   
   
       3 . The beam of  claim 2  wherein said cementitious mixture forming the exterior layer has the same composition as the mixture filling the tubular member. 
   
   
       4 . The beam of  claim 3  wherein said layer is approximately 1/16 inch thick. 
   
   
       5 . The beam of  claim 1  wherein the tubular member is cardboard. 
   
   
       6 . The beam of  claim 5  wherein said rectangular plates are made of sheet metal. 
   
   
       7 . The beam of  claim 6  wherein the dimensions of the rectangular, tubular cardboard member are approximately equal to the dimensions of a standard, dimensional two by four. 
   
   
       8 . The beam of  claim 1  wherein said rod has a nominal diameter between ⅛ inch and 3/16 inch. 
   
   
       9 . The beam of  claim 8  wherein said rod diameter is 5/32 inch. 
   
   
       10 . The beam of  claim 1  wherein said cementitious mixture comprises prior to setting 30% water, 10% sand, 15% Perlite, 20% cement, 5% mortar, 10% cardboard and 10% miscellaneous. 
   
   
       11 . The beam of  claim 10  wherein said cementitious mixture contains synthetic fibers. 
   
   
       12 . The beam of  claim 11  wherein said tubular member has a thickness of about ⅛ inch. 
   
   
       13 . The beam of  claim 1  wherein said cementitious material is permitted to set for 30 days prior to use of the beam. 
   
   
       14 . The beam of  claim 1  wherein said rods are prestressed prior to embedding in said cementitious mixture and relieved after said mixture has set. 
   
   
       15 . A building construction beam of cementitious material comprising:
 an elongated, rectangular, tubular hollow member;   a plurality of rectangular plates having a central opening and at least two circular openings adjacent to the corners of said plates, said plates disposed within said tubular member at longitudinally spaced apart locations;   elongated high tensile strength wires, at least one for each plate corner opening, extending through the plate circular openings along the full length of the tubular member; and   a cementitious mixture filling the tubular hollow member comprising cement, sand, water and a low density, expanded silicon dioxide material.   
   
   
       16 . The building construction beam of  claim 15  wherein said expanded silicon dioxide material is Perlite. 
   
   
       17 . The building construction beam of  claim 16  additionally including a screen material encasing the tubular hollow member. 
   
   
       18 . The building construction beam of  claim 17  wherein said elongated, rectangular, tubular member is formed of cardboard. 
   
   
       19 . The building construction beam of  claim 17  wherein said elongated, rectangular, tubular member is cardboard. 
   
   
       20 . A method for fabricating a cementitious material building construction beam comprising the steps of:
 providing an elongated, rectangular, tubular hollow member;   wrapping a screen material so as to encase the tubular cardboard member;   providing a plurality of rectangular plates having a central opening and at least two circular openings adjacent two of the corners of the plates;   positioning the plurality of rectangular plates within the tubular cardboard member at spaced apart locations;   inserting elongated high tensile strength rods through said circular plate openings thereby positioning the rods to be adjacent the tubular cardboard member;   filling the tubular hollow member with a cementitious mixture including cement, sand, water and a low density, expanded silicon dioxide material.   
   
   
       21 . The method of  claim 20  including applying an exterior thin layer of cementitious material to the outside of the tubular member so as to encase the screen material in a relatively thin layer of cementitious mixture. 
   
   
       22 . The method of  claim 21  wherein the elongated rods are inserted into the circular openings of the plurality of plates and are secured in a spaced apart location prior to positioning the rod-plate subassembly into the rectangular tubular member. 
   
   
       23 . The method of  claim 22  wherein the cementitious mixture comprises 30% water, 10% sand, 15% Perlite, 20% cement, 5% mortar, 10% cardboard and 10% miscellaneous. 
   
   
       24 . The method of  claim 20  wherein the final step of the fabrication process is permitting the cementitious mixture to cure for a period of at least 30 days.