Ultra-high performance concrete reinforcement bars

Abstract

The ultra-high performance concrete reinforcement bars replace conventional steel tension bars and the like in the reinforcement of construction elements, such as concrete beams. The ultra-high performance concrete reinforcement bars are formed from ultra-high performance concrete reinforced with steel fiber. The reinforcement bars are preferably deformed to improve bonding at the interface between conventional concrete in the beam and the reinforcement bars. The bars are disposed in the area of the beam known as the tension area when the beam is subjected to a bending stress to provide tensile reinforcement.

1 . An ultra-high performance concrete reinforcement bar, comprising an elongate bar made from ultra-high performance concrete having discontinuous steel reinforcing fibers, the elongate bar being dimensioned and configured for providing tension reinforcement for a conventional concrete construction element, wherein the transverse cross sectional dimensions are in the range of approximately 1 inch to 2 inches. 
     
     
         2 . The ultra-high performance concrete reinforcement bar according to  claim 1 , wherein the elongate bar is deformed along the length of the elongate bar. 
     
     
         3 - 6 . (canceled) 
     
     
         7 . The ultra-high performance concrete reinforcement bar according to  claim 2 , wherein the top face of the elongate bar is rough for further improving bonding between the elongate bar and the conventional concrete of the conventional concrete construction element. 
     
     
         8 . The ultra-high performance concrete reinforcement bar according to  claim 1 , wherein the elongate bar is square in transverse cross section. 
     
     
         9 - 13 . (canceled) 
     
     
         14 . The ultra-high performance concrete reinforcement bar according to  claim 1 , wherein said steel reinforcing fibers have a diameter of about 0.15 mm, a length of about 12.7 mm, and an ultimate tensile strength of about 2500 MPa. 
     
     
         15 . The ultra-high performance concrete reinforcement bar according to  claim 1 , wherein said steel reinforcing fibers comprise about 6.2% by weight of the ultra-high performance concrete. 
     
     
         16 . The ultra-high performance concrete reinforcement bar according to  claim 1 , wherein said ultra-high performance concrete has a water-to-cementitious material ratio of about 0.145. 
     
     
         17 . The ultra-high performance concrete reinforcement bar according to  claim 1 , wherein said elongate bar has flexural tensile strength of about 32 MPa and direct tensile strength of about 11-12 MPa. 
     
     
         18 . In combination, a hybrid concrete construction element having a conventional concrete component and an ultra-high performance concrete reinforcement bar component, comprising:
 an elongate concrete construction element made from conventional concrete, the construction element having a compression area and a tension area when subjected to a bending stress, wherein each of the compression and tension areas includes an elongated compression face and tension face, respectively; and   at least one elongate reinforcement bar made from ultra-high performance concrete having steel reinforcing fibers, the at least one elongate reinforcement bar being incorporated into and extending along the tension face, thereby providing the tension reinforcement for the construction element.   
     
     
         19 . (canceled) 
     
     
         20 . The combination according to  claim 18 , wherein the at least one elongate reinforcement bar is deformed along its length. 
     
     
         21 . The combination according to  claim 18 , wherein the at least one elongate reinforcement bar comprises a pair of ultra-high performance concrete reinforcement bars extending in parallel along the length of the tension face of the construction element. 
     
     
         22 . In combination, a hybrid concrete construction element having a conventional concrete component and an ultra-high performance concrete reinforcement bar component, comprising:
 an elongate concrete construction element made from conventional concrete, the construction element having a compression area and a tension area when subjected to a bending stress; and   at least one elongated, deformed reinforcement bar made from ultra-high performance concrete having steel reinforcing fibers, the at least one elongate, deformed reinforcement bar being incorporated into and extending along the tension area thereby providing the tension reinforcement for the construction element.