Apparatus and method for forming cavities of complex configuration within concrete

Abstract

A form for creating cavities within large concrete structures, wherein the formed is created by interconnecting a plurality of section members, the section members having flexible mold skeleton members retaining polymer-aggregate panel members, and wherein the form may be internally pressurized to increase its rigidity and weight-bearing capability. The mold skeleton members have annular and longitudinal flanges that are used as planning guides to form the external surface of the polymer-aggregate panel members. Preferably, spacer members are inserted between the annular and longitudinal flanges and the spacer members are used as planning guides. The adjacent section members are mechanically joined to each other, such that the form may be disassembled and re-used.

1 . A form for creating smooth-walled tubular cavities within concrete structures, said form comprising: 
 a plurality of interconnected section members, each said section member comprising a mold skeleton member and a polymer-aggregate concrete panel member bonded to said mold skeleton member, the combination of said interconnected section members defining a smooth tubular exterior surface.    
   
   
       2 . The form of  claim 1 , wherein said mold skeleton members are lightweight and flexible.  
   
   
       3 . The form of  claim 2 , wherein said mold skeleton members are composed of glass fiber reinforced resin.  
   
   
       4 . The form of  claim 1 , wherein said mold skeleton members each comprises an interior tubular wall portion, annular flanges and longitudinal flanges.  
   
   
       5 . The form of  claim 4 , wherein said annular flanges and longitudinal flanges extend internally and externally to said interior tubular wall portion to define flange internal portions and flange external portions.  
   
   
       6 . The form of  claim 5 , wherein said external flange portions retain said polymer-aggregate concrete panel member.  
   
   
       7 . The form of  claim 6 , wherein said external flange portions each comprise a peripheral edge and said polymer-aggregate concrete panel member comprises a form surface, wherein said peripheral edges define the parameters of said form surface.  
   
   
       8 . The form of  claim 4 , further comprising mechanical fasteners joining said internal flange portions of adjacent section members.  
   
   
       9 . The form of  claim 4 , further comprising spacer members disposed between adjacent annular flanges and between adjacent longitudinal flanges.  
   
   
       10 . The form of  claim 9 , wherein each said spacer member comprises a spacer peripheral edge, wherein each said annular flange and each said longitudinal flange comprises a peripheral edge, and wherein said spacer peripheral edges extend beyond said peripheral edges of said annular and longitudinal flanges.  
   
   
       11 . The form of  claim 10 , wherein each said polymer-aggregate concrete panel member comprises a form surface, and wherein said spacer peripheral edges define said form surface  
   
   
       12 . The form of  claim 1 , wherein said interconnected section members define an access bore, and further comprising pressurizing means to pressurize said access bore.  
   
   
       13 . The form of  claim 12 , further comprising pneumatic sealing means to seal said access bore.  
   
   
       14 . The form of  claim 1 , further comprising an external glaze layer applied to said polymer-aggregate concrete panel member.  
   
   
       15 . The form of  claim 1 , wherein said polymer-aggregate concrete panel member has a density of approximately 500 grams per liter.  
   
   
       16 . A tubular form for creating smooth-walled tubular cavities within concrete structures, said form comprising: 
 a plurality of interconnected rigid section members, each said section member comprising a lightweight, flexible mold skeleton member and a polymer-aggregate concrete panel member bonded to said mold skeleton member, the combination of said interconnected section members defining a smooth tubular exterior surface;    wherein said mold skeleton members each comprises an interior tubular wall portion, annular flanges and longitudinal flanges; said annular flanges and longitudinal flanges extending internally and externally to said interior tubular wall portion to define flange internal portions and flange external portions;    wherein said polymer-aggregate concrete panel member completely fills the area between said externally extending flange external portions; and    wherein said section members are interconnected by joining said flange internal portions of adjacent said section members.    
   
   
       17 . The form of  claim 16 , wherein said interconnected section members define an access bore, and further comprising pressurizing means to pressurize said access bore.  
   
   
       18 . The form of  claim 16 , further comprising spacer members disposed between adjacent said annular flanges and between adjacent said longitudinal flanges, said spacer members extending externally beyond said annular flanges and said longitudinal flanges, wherein said polymer-aggregate concrete panel completely fills the area between said spacer members.  
   
   
       19 . A tubular form comprising a plurality of interconnected rigid section members having a smooth-walled exterior surface for forming a curvilinear, tubular, smooth-walled cavity within a concrete structure, said tubular form produced by: 
 providing a plurality of section members each comprising a flexible mold skeleton member comprising a tubular wall portion, a pair of annular flanges and a pair of longitudinal flanges, with said annular flanges and said longitudinal flanges extending internally and externally to said tubular wall portion;    joining said section members to each other to create a three-dimensional tubular form;    applying polymer-aggregate concrete onto the exterior of said section members to completely fill the space between said annular flanges and said longitudinal flanges, planing said sprayed polymer-aggregate concrete using said annular flanges and said longitudinal flanges as planing guides to produce a smooth-walled, curvilinear exterior surface on said three-dimensional tubular form, and allowing said polymer-aggregate concrete to cure to rigidify said section members.    
   
   
       20 . A tubular form comprising a plurality of interconnected rigid section members having a smooth-walled exterior surface for forming a curvilinear, tubular, smooth-walled cavity within a concrete structure, said tubular form produced by: 
 providing a plurality of section members each comprising a flexible mold skeleton member comprising a tubular wall portion, a pair of annular flanges and a pair of longitudinal flanges, with said annular flanges and said longitudinal flanges extending internally and externally to said tubular wall portion;    inserting spacer members between said annular flanges and said longitudinal flanges of adjoining said section members, said spacer members extending externally beyond said annular flanges and said longitudinal flanges;    joining said section members to each other to create a three-dimensional tubular form;    applying polymer-aggregate concrete onto the exterior of said section members to completely fill the space between said annular flanges, said longitudinal flanges and said spacer members, planing said sprayed polymer-aggregate concrete using said spacer members as planing guides to produce a smooth-walled, curvilinear exterior surface on said three-dimensional tubular form, and allowing said polymer-aggregate concrete to cure to rigidify said section members.