Bending and End of Hot-Rolled Ribbed Steel Bar
Hot-rolled rebar, also known as hot-rolled ribbed steel bar, is one of the most widely used steel products used in the reinforcement of concrete or column-supported structure due to its strength and relatively low cost. An important factor in the performance of a concrete structure reinforced with hot-rolled rebar is its bending and end characteristics. The bending and end characteristics of hot-rolled rebar are not only important to ensure the integrity of the structure, but are also crucial to maintain the safety of the people using it. This article will discuss the bending and end requirements of hot-rolled rebar according to the standard GB 1499-1998.
Bending of hot-rolled rebar requires that the bar is bent in a certain radius along the full length of the bar. The minimum inside radius for bending hot-rolled rebar should not be less than 3 times the nominal diameter of the bar, or the radius of the bending machine used for the bending operation, whichever is greater. The bending should be uniform along the full length of the bar and should not produce cracks or breaks on the surface of the bar. The ends of the bar should have a smooth transition from the bent part to the straight part.
The end of a hot-rolled ribbed steel bar, or the transition to a straight portion of the bar, is an important factor in the performance of the reinforced concrete structure. According to the standard GB 1499-1998, the end of the bar should be at least 25 mm long and have a smooth transition between the bent and straight portions of the bar. The end of the bar should be tapered so as not to create any sharp protrusions or protruding fins. The maximum angle of the taper should be between 30 and 45 degrees.
Hot-rolled ribbed steel bar is an important and widely used material in the field of reinforcement of concrete structures, and thus its bending and end requirements should strict adhere to the standards set by GB 1499-1998. Gaseous quench test and fracture test should be used to test the end bending of hot-rolled ribbed steel bar to ensure its ductility and performance in reinforced concrete structures. Following the requirements of bending and end of hot-rolled ribbed steel bar, as required by the standard GB 1499-1998 and by conductingbending tests and end tests, one can ensure that the bar is suitable and safe for being used in reinforced concrete structures.
