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Reinforcing steel

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reinforcing steel produced in several forms such as deformed bars, plain bars, and welded wire fabric. deformed bars comes with protruding ribs pattern. the pattern varies for different manufacturer's. these protruding ribs will strengthen the bond between reinforcing bars and concrete. deformed bars are used mostly in concrete structures. plain bars have a limited used in reinforced concrete. sometimes they are used to confine the vertical deformed bars for a column primarily.




welded wire fabric used for slabs, pavements, and places where it is difficult to provide a cover for regular reinforcing bars. welded wire fabric composed of cold drawn wires placed in both directions and welded at intersection points. the spacing between wires and sizes will be provided by the designer. smooth wires are denoted by letter W. letter W will be followed by a number representing the cross-section area of the wires. deformed wires are denoted by D. deformed wires will bond better than smooth wires. smooth wires will develop bonds with concrete at intersection points.
Figure 1


Table no:1 showing the sizes and unit weight for reinforcing bars in SI units. and table no: 2 showing the sizes and unit weight of reinforcing bars in English units. reinforcing bar standards length is 
12m, 14m, 15m. also reinforcing bar can be produced in special length ranges from 6m to 18 but it is required a prior order. 
                         
                                                                         Table 1
                       


                                     
Table 2


Table 3 showing grades of reinforcing bars. grade 460A reinforcing steel will have a yields stress of 460 MPa and a stress ratio(ultimate stress/yield stress) of 1.05. 460B has a higher stress ratio which means more ductility and higher ultimate stress.


Table 3

Marks indicating grades will be embossed in each reinforcing bar as showing in figure no:2.

Figure 2
Reinforcing bars shall be tested for the following tests:
  • Chemical composition
Figure 3

  • Elongation at maximum force
  • Yield strength(Re)
  • Tensile strength(Rm)
Figure 4





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