Due to its excellent characteristics, it is the steel that must be used for medium-sized and above building components. Rebar is widely used, mainly in civil engineering construction such as houses, bridges and roads.
So do you know what is the inspection standard for rebar? Now let’s learn about rebar specification, appearance quality, standard number, composition inspection, etc.
The specification requirements of rebar shall be listed in the import and export trade contract. Generally, it shall include standard brand (type code), nominal diameter, nominal weight (mass), specified length and allowable deviation of the above indicators.
Rebar series with nominal diameters of 6, 8, 10, 12, 16, 20, 25, 32, 40 and 50mm are recommended in Chinese standards. The supply length is divided into fixed length and double length.
The selection range of fixed length of deformed steel bars exported from China is 6 ~ 12M, and that of deformed steel bars produced in Japan is 3.5 ~ 10m; If there are no requirements specified in the contract, the length of domestic screw thread steel is usually 9m and 12m.
(1) Surface quality. The surface quality of deformed steel bar is specified in relevant standards. It is required that the end shall be cut straight, and the surface shall be free of cracks, scabs and folds, harmful defects in use, etc.
(2) Allowable deviation of overall dimension. The requirements for the bending degree of deformed bar and the geometry of reinforcement are specified in relevant standards.
GB1499. 2-2007 (steel for reinforced concrete Part 2: hot rolled ribbed reinforcement)
GB1499. 2-2007 / xg1-2009 steel for reinforced concrete Part 2: hot rolled ribbed steel bar No. 1 amendment to national standard; GB / T 2101-2008 (general provisions for acceptance, packaging, marking and quality certificate of section steel).
GB1499. 1～GB1499. 3 (reinforcement 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 coil steel); Bs4449-97 (hot rolled steel bars for concrete structures).
(1) Test method: the standard test methods commonly used in the test and analysis of the above chemical components are as follows: GB / t223, jisg1211? 1215, bs1837, BS manual 19, etc.
(2) Composition index: the indexes for assessing the composition content of deformed steel bar mainly include: C, Mn, P, s, Si, etc., with different brands and different content
The approximate range is: C (0.10 ~ 0.40%), Mn < 1.80%, P < 0.050%, s < 0.050%, Si (0.60 ~ 1.00%).
Rebar is widely used in civil engineering construction such as houses, bridges and roads.
From public facilities such as expressways, railways, bridges, culverts, tunnels, flood control and dams to the foundation, beams, columns, walls and plates of housing buildings, threaded steel is an indispensable structural material.
With the deepening of China’s urbanization and the vigorous development of infrastructure construction and real estate, there is a strong demand for rebar.
Rebar is widely used in civil engineering construction such as houses, bridges and roads.
From public facilities such as expressways, railways, bridges, culverts, tunnels, flood control and dams to the foundation, beams, columns, walls and plates of housing buildings, threaded steel is an indispensable structural material.
With the deepening of China’s urbanization and the vigorous development of infrastructure construction and real estate, there is a strong demand for rebar.
Reinforced concrete structure is still the main structural form of buildings in China at present and for a long time in the future.
Therefore, it can be expected that the demand and output of rebar will remain at a high level.
According to statistics, the steel consumption of China’s construction industry accounts for about 50% of the total steel consumption.
As one of the industries with large resource consumption, in order to achieve sustainable development, the construction industry must adjust the consumption structure of building materials, vigorously apply high-strength reinforcement and high-performance concrete, and take the road of energy-saving development.
If we can improve the strength grade of the currently used reinforcement and concrete, it can bring great savings to the society.
According to the calculation, if the strength of the main stressed reinforcement of reinforced concrete can be increased to 400-500n / mm2 according to the requirements of the specification, about 10% of the current steel consumption can be saved.
