Rebar
- Apr 17, 2018 -


Rebar commonly known as steel Bar, also known as fine grain hot-rolled steel bar, its brand in the hot-rolled ribbed bar after the English abbreviation plus "fine" English (Fine) first letter. such as: HRBF335, HRBF400, HRBF500.

  There is a higher demand for the earthquake resistant structure of the applicable grade: In the existing brand after the addition of E (for example: hrb400e, hrbf400e).

  I. Overview Rebar commonly known as steel Bar, also known as fine grain hot-rolled steel bar, its brand in the hot-rolled ribbed bar after the English abbreviation plus "fine" English (Fine) first letter. such as: HRBF335, HRBF400, HRBF500.

  There is a higher demand for the earthquake resistant structure of the applicable grade: In the existing brand after the addition of E (for example: hrb400e, hrbf400e).

  Ii. types (1) Performance classification, according to the implementation standard of rebar in China (G b1499.2-2007), according to the intensity level (yield point/tensile strength) will be divided into 3 grades of rebar, (2) according to the use of rebar classification, such as divided into reinforced concrete with ordinary steel and stress reinforcement, concrete with heat treatment of steel bars.

  (3) According to the appearance of points, divided into ribbed bars and light round steel bars.

  The difference between rebar and light round bar The difference between the rebar and the light round bar is that the surface is provided with longitudinal ribs and transverse ribs, usually with the longitudinal ribs and the transverse ribs uniformly distributed along the length direction. Rebar belongs to small steel steel, mainly used in the skeleton of reinforced concrete building components. In the use of a certain mechanical strength, bending deformation performance and process welding performance.

  The raw material billet for the production of threaded steel is the carbon structural steel or low alloy structural steel which is treated by calm smelting, and the finished steel bar is delivered in hot-rolled, normalizing or hot-rolling condition.

  Main origin: North China, east China, northeast, such as Shougang, Tanggang, Xuangang, bearing steel, emerging casting pipe, Jian Long, Xilin, North Taiwan, Fu Steel, sand steel, Hebei steel and so on.

  Specifications Specification requirements for threaded steels shall be specified in the import and export trade contracts. Generally should include the standard Grade (type code), the nominal diameter of the steel bar, nominal weight (quality), the specified length and the above indicators of the tolerance value and so on. China's standard recommended nominal diameter of 6, 8, 10, 12, 16, 20, 25, 32, 40, 50mm rebar series. The supply length is fixed ruler and two of times ruler.

  Our country export rebar fixed ruler choice range is 6~12m, the Japanese production rebar fixed ruler choice range is 3.5~10m; domestic domestic sale rebar If the contract does not specify the requirements, usually set the ruler is 9m, 12m two length.

  Iii. use

  Widely used in housing, bridges, roads and other civil engineering construction. 1) Surface quality.

  The standard of the surface quality of threaded steel is stipulated that the end should be cut straight, no surface cracks, scarring and folding, no use of harmful defects. 2) The dimension deviation of the form is allowed. The requirements of bending degree and geometrical shape of rebar are stipulated in the relevant standards.

  As our standard stipulates, the bending degree of straight bar should not affect the normal use, the total bending degree is not more than 0.4% of the total length of the bar.

  IV. Technical standards

  Gb1499.2-2007 (2nd part of steel for reinforced concrete: Hot rolled ribbed steel bars) GB1499.2-2007/XG1-2009 Steel 2nd: Hot-rolled ribbed bar, National standard 1th Amendment list; gb700-2006 (carbon structural steel); GB/T 2101-2008 (General provisions for acceptance, packaging, marking and quality certificates of section Steel) gb1499.1~gb1499.3 (steel for concrete), JIS g3112-87 (98) (bar steel for reinforced concrete), jisg3191-66 (94) (Shape, size, weight and allowable difference of hot-rolled bar steel and rolled bar steel); bs4449-

  97 (Hot rolled steel bar for concrete structure).

  V. Chemical composition

  Grade chemical composition, 100% C Si Mn P S Ceq

  HRB400 0.25 0.80 1.60 0.045 0.045 0.54

  HRB500 0.25 0.80 1.60 0.045 0.045 0.55

  (1) Composition test

  1) test methods: The chemical composition of the inspection and analysis of the common standard test methods are as follows: gb/t223, jisg1211?1215, BS1837, BS manual 19. 2) component index: Check rebar component content of the main indicators are: C, Mn, P, S, Si and other items, different grades, the content of the difference, the broad range is: C (0.10~0.40%), mn<1.80%, p<0.050%, s<0.050%, Si (0.60~1.00%

  ).

  (2) Surface quality Cracks, scarring and folding shall not be allowed on the surface of steel bars.

  The surface of the steel bar may have convex blocks, but shall not exceed the height of the transverse rib, and the depth and height of other defects on the steel surface shall not be greater than the allowable deviation of the size of the part.