Post-tension anchor seal cap

Abstract

An apparatus and method for reducing corrosion in post-tension construction is described. An anchor is engagable with a post-tension tendon and comprises an anchor base and sheath engaged with the anchor base, and a cap for sealing the portion of the tendon within the anchor. The sheath includes a cylindrical extension having a contact end distal from the anchor base for contacting the tendon as the tendon is inserted through the cylindrical extension and the anchor base aperture. The cap can include a detachable extension for supporting a pocketformer having an aperture therethrough.

What is claimed is:  
     
         1 . An anchor for engagement with a post-tension tendon, comprising: 
 an anchor base having an aperture oriented along a centerline for permitting insertion of the tendon therethrough, wherein said aperture has first and second surfaces each having a different shape relative to said aperture centerline, and wherein said first and second surfaces continuously enlarge the size of said aperture from one side of said anchor base to another side of said anchor base;    a sheath engaged with said anchor base, wherein said sheath includes a cylindrical extension having a contact end distal from said anchor base for contacting the tendon as the tendon is inserted through said cylindrical extension and said anchor base aperture; and    a cap for sealing the tendon within said anchor base aperture.    
     
     
         2 . An anchor as recited in  claim 1 , further comprising a corrosion resistant material positioned within said cylindrical extension.  
     
     
         3 . An anchor as recited in  claim 1 , wherein said sheath substantially encapsulates all of said anchor base.  
     
     
         4 . An anchor as recited in  claim 1 , further comprising a threadform between said cap and said sheath for providing detachable engagement of said cap to said sheath.  
     
     
         5 . An anchor as recited in  claim 1 , wherein said cap has a selected exterior shape adapted to a tool for facilitating engagement of said cap with said sheath.  
     
     
         6 . An anchor as recited in  claim 1 , wherein said cap includes a cavity for retaining corrosion resistant material.  
     
     
         7 . An anchor as recited in  claim 1 , wherein said cap further includes a cap extension having an exterior surface and having a hollow interior for permitting passage of the tendon therethrough.  
     
     
         8 . An anchor system as recited in  claim 7 , wherein said cap extension is selectively attachable to and detachable from said cap.  
     
     
         9 . An anchor system as recited in  claim 7 , wherein said cap has a hollow interior for permitting passage of the tendon therethrough and has an end extendible through said anchor base aperture and attachable to said anchor base.  
     
     
         10 . An anchor system as recited in  claim 9 , wherein said cap end is extendible through said anchor base aperture and is attachable to said sheath.  
     
     
         11 . An anchor system as recited in  claim 9 , further comprising a hollow sheath extension engaged with said sheath and extending to a position distal from said anchor base, and wherein said cap end is extendible through said anchor base aperture and is attachable to said sheath extension to provide a continuous path for insertion of the tendon through said sheath extension and through said cap.  
     
     
         12 . An anchor system as recited in  claim 1 , wherein said cap comprises a substantially cylindrical tube having a first end for threadable engagement with said sheath and having a second end extending to a point distal from said sheath.  
     
     
         13 . An anchor as recited in  claim 1 , wherein said cap comprises a pocketformer.  
     
     
         14 . An anchor as recited in  claim 1 , wherein said cap is sealed to prevent intrusion of fluids into said anchor base aperture.  
     
     
         15 . A post-tension anchor system, comprising: 
 a post-tension tendon having a sheath and inner wire strands;    an anchor base having a shaped aperture for permitting insertion of said tendon therethrough;    a sheath engaged with said anchor base, wherein said sheath includes a cylindrical extension having a contact end distal from said anchor base for contacting the tendon as the tendon is inserted through said cylindrical extension and said anchor base aperture; and    a cap for sealing the tendon within said said anchor base aperture.    
     
     
         16 . An anchor system as recited in  claim 15 , wherein said cap includes a cap extension having an exterior surface and having a hollow interior for permitting passage of the tendon therethrough.  
     
     
         17 . An anchor system as recited in  claim 15 , further comprising a pocketformer engagable with said cap extension exterior surface.  
     
     
         18 . An anchor system as recited in  claim 17 , further comprising a lock for retaining said pocketformer in a selected position relative to said cap extension exterior surface.  
     
     
         19 . An anchor system as recited in  claim 18 , wherein said lock comprises a threadform between said pocketformer and said cap extension.  
     
     
         20 . An anchor system as recited in  claim 15 , further comprising a wedge for engagement with said tendon and with said anchor base shaped aperture.