The manufacturer of steel plate tells you the classification and use of rebar.
Threaded steel is commonly known as hot-rolled ribbed bar. There are two commonly used classification methods. One is to classify or classify the steel according to the cross-section shape of the ribs and the distance between the ribs. For example, the British code (BS4449) classifies the steel into type I and type II. This classification method mainly reflects the grip function of thread steel. Secondly, according to the function classification (grade), for example, in the Chinese code (GB1499.2-2007), the screw bar is divided into three grades according to the strength grade (yield strength); in the Japanese industrial code (JISG3112), the screw bar is divided into five varieties according to the comprehensive function. In addition, it can also be classified according to usage, such as reinforced concrete with general steel and reinforced concrete with heat treatment steel bar.
GB1499.2-2007 is the current standard for the performance of threaded steel in China, which is divided into general hot-rolled steel bars and fine grain hot-rolled steel bars. According to the standard definition, the hot-rolled bar is the steel bar delivered in hot rolling condition. Its metallographic arrangement is mainly ferrite plus pearlite, and no other arrangement can affect the use of function. Fine grain hot-rolled steel bar is a kind of fine grain steel bar formed by controlled rolling and controlled cooling process in the process of hot rolling. The main metallographic arrangement is ferrite plus pearlite, and no other arrangement can affect the use function. The grain size is not larger than 9 grade.
Generally, the trademark of hot-rolled ribbed bar consists of HRB and yield strength eigenvalues, while the trademark of fine-grained hot-rolled ribbed bar consists of HRBF and yield strength eigenvalues. H, R and B are the first letters of Hotrolled, Ribbed and Bars respectively; F is the first letter of Fine. General hot-rolled bar trademarks are divided into HRB335, HRB400, HRB500 trademarks; fine-grained hot-rolled bar trademarks are divided into HRBF335, HRBF400, HRBF500 trademarks.
In addition, the National Standard 1499.2-2007 also stipulates that the seismic steel bars with higher requirements are marked by adding E (such as HRB400E, HRBF400E) behind the existing trademarks. The seismic steel bars should satisfy the following three requirements besides all the functional indexes of the general steel bars stipulated in the code:
The ratio of the measured tensile strength to the measured compliance strength of the 1. aseismic reinforcement is not less than 1.25.
2. the ratio of the measured compliance strength to the standard strength of the reinforcement is not greater than 1.30.
3. the maximum elongation of reinforcement is not less than 9%.
Rebar is widely used in building construction such as houses, bridges and roads. From highways, railways, bridges, culverts, tunnels, flood control, dams and other public facilities to the bottom of the building, beams, columns, walls, panels, screw steel is an indispensable structural material. At present, China is vigorously promoting the use of high-strength rebar, in the same strength and standard scale, the use of three-grade rebar than two-grade rebar steel consumption decreased about 11% - 15%.