Hot-rolled Ribbed Steel Bars Weight and Allowable Deviation (GB 1499-1998)
Hot-rolled ribbed steel bar is the main reinforcing bar used in the reinforced concrete structure of China. With the continuous development of society and the deepening of engineering construction, the variety, specifications, amount and quality of hot-rolled ribbed steel bars in construction have become increasingly important. This requires that hot-rolled ribbed steel bars should have certain fixed specifications and strict quality control, to form an effective guarantee on the construction.
The specification and tolerance of hot-rolled ribbed steel bar in Japan are mainly regulated by the Standard of Hot-rolled Ribbed Steel Bars JIS G 3112-2010, which is gradually accepted by more and more countries and regions. While in China, the standardhot-rolled ribbed steel bars is mainly regulated by the hot-rolled Ribbed Steel Bar Standard GB1499-1998.
The hot-rolled ribbed steel bar in GB 1499-1998 is mainly divided into two types: ordinary ribbed steel bar and grade-2 ribbed steel bar. According to the nominal diameter range, the steel bar is divided into 8 levels with the steel bar of diameter Φ10—Φ50, Φ6—Φ40, Φ4—Φ12 and so on. The ordinary ribbed steel bars should have their nominal diameters meet the corresponding provisions in the eight levels and below, as for the grade-2 ribbed steel bars, the nominal diameter shall be Φ8—Φ50.
In addition, the weight of hot-rolled ribbed steel bar shall be limited by three types, including the unit weight of rebar, arbitrary length weight and theoretical yield. The unit weight of rebar is divided into three levels and below which differs in the design of different ribbed steel bar models. The arbitrary length weight of hot-rolled ribbed steel bar is the actual weight of the rebar in meters with certain length, which is actually measured in common construction practice. The theoretical yield of hot-rolled ribbed Steel bar is the weight calculated according to its length and section area.
The existing weight allowances of hot-rolled ribbed steel bar is -3.5％—+3.5％. That is to say, the actual measured weight should not exceed the allowable deviations from 3.5％ under maximum. It is necessary to strictly check the weight of hot-rolled ribbed steel bar before use to ensure that it meets the requirements of the technical standard.
In summary, the weight and allowable deviation of hot-rolled ribbed steel bar are as follows. It mainly includes the specification, weight and allowable deviation of ordinary ribbed steel bar and grade-2 ribbed steel bar. For its weight, there are three types of hot-rolled ribbed steel bar weights including unit weight of rebar, arbitrary length weight and theoretical yield. According to the hot-rolled ribbed steel bar weight and allowable deviation GB 1499-1998, the actual measured weight should not exceed the maximum allowable deviation of 3.5%. It is necessary to firmly check the weight of hot-rolled ribbed steel bar before to ensure that its quality meets the requirements of the technical standard.
