Reinforcing bar and method for manufacturing the same

Abstract

An improved reinforcing bar (REBAR) and the process for manufacturing the same for the enhancement of the life span of reinforced concrete, reinforced concrete structures and constructions as well as reinforced concrete elements without the need for any surface treatment or surface protection to REBAR or addition of admixture in concrete or without any other special provision or effort following the making/manufacturing of REBAR where the rebar, even when made of high strength steel or any other material, has a plain surface but with a deformed axis for use in all concrete constructions. The improved reinforcing bar (REBAR) for reinforced concrete constructions and reinforced concrete structures comprising a high strength material, a circular or oval or elliptical cross section of said bar; deformation of the axis of the bar in specific plane(s).

1 . An improved reinforcing bar (REBAR) for reinforced concrete constructions and reinforced concrete structures comprising :
 a) a high strength material;   b) a circular or oval or elliptical cross section of said bar;   c) deformation of the axis of the bar in specific plane(s).   
     
     
         2 . The bar as claimed in  claim 1  wherein said deformation of axis which makes the bar look undulating/wavy with the amplitude and pattern of axis deformation as well as the distance between successive peaks of the said undulations is varied such that high/increased gripping capacity and bond or resistance to pull-out forces is maintained without compromising in any significant way the overall linear characteristic of the bar and yet avoiding stress concentration and its ill effects. 
     
     
         3 . The bar as claimed in  claim 1  wherein said deformation is in single plane or in multiple planes. 
     
     
         4 . The bar as claimed in  claim 1  wherein said bar is of circular shape. 
     
     
         5 . The bar as claimed in  claim 1  wherein said amplitude of surface or axis deformation is 1 mm to 10 mm. 
     
     
         6 . The bar as claimed in  claim 1  wherein said resistance to pull out forces is at least 50% higher compared to resistance of straight bars with plain surface. 
     
     
         7 . The bar as claimed in  claims 1  to  6  wherein said bar has a plain surface and a deformed axis. 
     
     
         8 . The bar as claimed in  claim 1  wherein said high strength material comprises of glass fiber or carbon fiber or aramid or other high strength materials, made without or with the benefit of nanotechnology, preferably steel. 
     
     
         9 . A method for manufacturing of an improved reinforcing bar (REBAR) for reinforced concrete constructions and reinforced concrete structures by hot working comprising steps of :
 making of billet for high strength bar of steel;   reheating the said billet;   rolling the said billet in a rolling mill and making bars of the desired size and shape;   deforming the said bars using gear rollers or by any other device or means;   optionally providing any heating/cooling treatment;   cutting bars into desired lengths using shears   cooling of said bars in a cooling bed.   
     
     
         10 . A method for manufacturing of an improved reinforcing bar (REBAR) for reinforced concrete constructions and reinforced concrete structures by cold working comprising steps of :
 making of billet for high strength bar of steel;   reheating the billet;   rolling the said billet in a rolling mill to make bars of the desired size and shape;   cutting bars into desired lengths using shears;   cooling of said bars in a cooling bed;   deforming the said bars using gear rollers or by any other device or means;   optional annealing to relieve residual stresses.   
     
     
         11 . The method for manufacturing of an improved bar as claimed in any of  claim 9  or  10  wherein said rolling mill process is followed by quenching of said bar in case of thermo mechanical treatment. 
     
     
         12 . The method as claimed in any of  claim 9  or  10  wherein said rolling mill process is further followed by quality check of splitting tendency and other quality check. 
     
     
         13 . The method as claimed in  claim 10  wherein said process of deformation is followed by annealing the said bar to remove or reduce built-in residual stresses by a process of gradually heating and cooling. 
     
     
         14 . The method as claimed in  claim 9  or  10  wherein said rollers/gears have horizontal or vertical or inclined axes. 
     
     
         15 . The method as claimed in  claim 9  or  10  wherein said hot working temperature in case of steel is around 900° C. to 1200° C. 
     
     
         16 . (canceled)