Fabric column and pad concrete form

Abstract

A lightweight and flexible concrete forming tube for columns and pads is disclosed, wherein the tube has a very thin wall of high strength fabric and a longitudinal fabric tab running the length of the tube. The tab is sandwiched between two vertical support members made of lumber. The vertical support members and attached fabric tube are then accurately located and braced. As the interior of the tube is filled with concrete, the hydrostatic pressure causes the tube to form a cylindrical shape, thereby accurately aligning itself across from the vertical support members. The use of fabric prevents the problems associated with using cardboard forms, which weaken when exposed to moisture.

What is claimed is:  
     
         1 . A prefabricated column or pad tube form comprising: 
 a. At least one flexible sheet form element of indefinite length and specified width such that one longitudinal edge is joined to either: 
 i. The opposing longitudinal edge, at a specific distance from the edge to create a flexible tube form element of indefinite length, specific diameter, and a longitudinal tab adjacent to the joining width;  
 ii. The adjacent longitudinal edge of a separate flexible sheet form element, at a specific distance from its edge to create at least a portion of a flexible tube form element of indefinite length, and longitudinal tab adjacent to the joining width of indefinite length, so that the multiplicity of joined flexible sheet form elements forms a specific diameter tube with a multiplicity of longitudinal tabs adjacent to each joining width.  
   
     
     
         2 . The prefabricated column or pad tube form as claimed in  claim 1 , in which the flexible sheet form element is made of a woven fabric.  
     
     
         3 . The prefabricated column or pad tube form as claimed in  claim 2 , in which the woven fabric is of such a nature that it adheres to the hardened concrete, and cannot be stripped.  
     
     
         4 . The prefabricated column or pad tube form as claimed in  claim 3 , in which the woven fabric contains certain high strength warp and or weft elements to add structural strength to the concrete column or pad.  
     
     
         5 . The prefabricated column or pad tube form as claimed in  claim 1 , in which the longitudinal edges of at least two adjacent flexible sheet form elements are longitudinally joined temporarily by a zipper or other temporary forming method.  
     
     
         6 . A method of constructing a concrete column comprising the steps of: 
 a. Cutting off a specified length of at least one flexible sheet form element and at least one longitudinal tab joined into a tube form element of specified diameter, with the specified length equal to the height of the desired concrete column;    b. Sandwiching the longitudinal tabs between pairs of vertical support members;    c. Positioning and bracing the vertical support members around the circumference of the proposed column;    d. Supplying a flowable and settable foundation material to substantially fill the space within the flexible tube element.    
     
     
         7 . A method of constructing a concrete column as claimed in  claim 6  in which the flexible tube form element is left in place on the concrete surface.  
     
     
         8 . A method of constructing a concrete pad comprising the steps of: 
 a. Cutting off a specified length of at least one flexible sheet form element and at least one longitudinal tab joined into a tube form element, of specified diameter and specified length equal to the height of the desired concrete pad;    b. Driving stakes around the perimeter at the location of the desired pad, the spacing of the stakes equal to the spacing of the longitudinal tabs around the perimeter of the tube form element;    c. Attaching the longitudinal tabs to the stakes;    d. Supplying a flowable and settable foundation material to substantially fill the space within the flexible tube form element.