Reusable wedge for post-tensioning concrete

Abstract

The present disclosure provides a wedge assembly for an anchor of a tendon for use in post tensioning concrete. The wedge assembly includes three circumferential wedge segments adapted to be placed on an exterior surface of a tendon and form a wedge assembly to be inserted into a receiving bore of an anchor assembly. Each wedge segment is threaded on the inside and each wedge segment is tapered from the first end to the second end at a taper angle. Finally, each wedge segment has an exterior surface configured to be inserted into an anchor assembly and has an annular groove around the exterior surface of each wedge segment and located at the first end and being configured to receive a ring.

What is claimed is: 
     
         1 . A wedge assembly for an anchor of a tendon for use in post tensioning concrete, comprising:
 three circumferential wedge segments adapted to be placed on an exterior surface of a tendon and form a wedge assembly to be inserted into a receiving bore of an anchor assembly, the wedge assembly having a first end and a second with each of the first end and the second end having a circular opening therein such that the tendon is surrounded by the wedge assembly and runs through the wedge assembly on a longitudinal axis of the wedge assembly;   each wedge segment being tapered from the first end to the second end at a taper angle, the taper angle being selected such that compressive force exerted by the wedge assembly against the tendon is substantially evenly longitudinally distributed when the wedge assembly is fully engaged in the receiving bore with the tendon under tension;   each wedge segment having an exterior surface configured to be inserted into an anchor assembly and having an annular groove, running circumferentially around the exterior surface of each wedge segment and located at the first end being configured to receive a ring; and   each wedge segment having an interior surface comprising a threaded segment.   
     
     
         2 . The wedge assembly of  claim 1 , wherein the threaded segment of each wedge segment comprises a buttress type thread. 
     
     
         3 . The wedge assembly of  claim 1 , wherein the wedge has a 10 degree taper at the first end. 
     
     
         4 . The wedge assembly of  claim 1 , wherein cut edges of each wedge segment are sanded. 
     
     
         5 . The wedge assembly of  claim 1 , wherein each wedge segment is heat treated to a case depth of 0.025 to 0.035 inches. 
     
     
         6 . The wedge assembly of  claim 5 , wherein each wedge segment is heat treated to a case hardness of 79-84 Rockwell Hardness A (HRA) and a core hardness of 36-46 Rockwell Hardness C (HRC). 
     
     
         7 . The wedge assembly of  claim 1 , wherein an angle at an edge of the circular opening at the second end of each wedge segment is 6 degrees. 
     
     
         8 . The wedge assembly of  claim 1 , wherein the wedge assembly is reusable. 
     
     
         9 . The wedge assembly of  claim 1 , wherein the tendon is epoxy coated. 
     
     
         10 . The wedge assembly of  claim 1 , wherein the tendon is mono-strand. 
     
     
         11 . The wedge assembly of  claim 1 , wherein the tendon is multi-strand. 
     
     
         12 . A wedge assembly for an anchor of a tendon for use in post tensioning concrete, comprising:
 three circumferential wedge segments adapted to be placed on an exterior surface of an epoxy coated tendon and form a wedge assembly to be inserted into a receiving bore of an anchor assembly and this is configured to be reusable, the wedge assembly having a first end and a second with each of the first end and the second end having a circular opening therein such that the tendon is surrounded by the wedge assembly and runs through the wedge assembly on a longitudinal axis of the wedge assembly, the first end having a first end angle of 10 degrees around a first end perimeter and the second end having a second end angle of 6 degrees around the second end perimeter;   each wedge segment being tapered from the first end to the second end at a taper angle of 7.5 degrees;
 each wedge segment having an exterior surface configured to be inserted into an anchor assembly and having an annular groove, running circumferentially around the exterior surface of each wedge segment and located at the first end and being configured to receive a ring; and 
   each wedge segment having an interior surface comprising a threaded segment running from proximate the first end to proximate the second end and comprising buttress type threads;   wherein further the wedge assembly is configured to be reusable.   
     
     
         13 . The wedge assembly of  claim 12 , wherein cut edges of each wedge segment are sanded. 
     
     
         14 . The wedge assembly of  claim 12 , wherein each wedge segment is heat treated to a case depth of 0.025 to 0.035 inches. 
     
     
         15 . The wedge assembly of  claim 14 , wherein each wedge segment is heat treated to a case hardness of 79-84 Rockwell Hardness A (HRA) and a core hardness of 36-46 Rockwell Hardness C (HRC). 
     
     
         16 . The wedge assembly of  claim 12 , wherein the tendon is mono-strand. 
     
     
         17 . The wedge assembly of  claim 12 , wherein the tendon is multi-strand. 
     
     
         18 . A wedge assembly for an anchor of a tendon for use in post tensioning concrete, comprising:
 three circumferential wedge segments adapted to be placed on an exterior surface of an epoxy coated tendon and form a wedge assembly to be inserted into a receiving bore of an anchor assembly and this is configured to be reusable, the wedge assembly having a first end and a second with each of the first end and the second end having a circular opening therein such that the tendon is surrounded by the wedge assembly and runs through the wedge assembly on a longitudinal axis of the wedge assembly, the first end having a first end angle of 10 degrees around a first end perimeter and the second end having a second end angle of 6 degrees around the second end perimeter;   each wedge segment being tapered from the first end to the second end at a taper angle of 7.5 degrees;   each wedge segment is heat treated to a case depth of 0.025 to 0.035 inches and to a case hardness of 79-84 Rockwell Hardness A (HRA) and a core hardness of 36-46 Rockwell Hardness C (HRC);   each wedge segment having an exterior surface configured to be inserted into an anchor assembly and having an annular groove, running circumferentially around the exterior surface of each wedge segment and located at the first end and being configured to receive a ring; and   each wedge segment having an interior surface comprising a threaded segment running from proximate the first end to proximate the second end and comprising buttress type threads;   wherein further the wedge assembly is configured to be reusable.   
     
     
         19 . The wedge assembly of  claim 18 , wherein the epoxy coated tendon is mono-strand. 
     
     
         20 . The wedge assembly of  claim 18 , wherein the epoxy coated tendon is multi-strand.