The on-site processing process of reinforcement depends on the type of finished products. The general processing processes include rust removal, straightening, shearing, bending, etc.

（一）Steel bar rust removal

Generally, the rust removal of reinforcement can be achieved through the following two ways: first, the rust removal can be solved simultaneously through other processes of reinforcement processing, such as the rust removal in the process of cold drawing of reinforcement or straightening of steel wire, which is the most reasonable and economical method; The second is through mechanical derusting, of which the more common is to use electric derusting machine for derusting. The diameter of the disc wire brush of the commonly used electric derusting machine is 20 ~ 30cm, the thickness is 5 ~ 15mm, the rotating speed is about 1000r / min, and the motor power is 1.0 ~ 1.5KW. In order to reduce dust flying during rust removal, dust hood and dust pipe shall be installed.

In addition, manual rust removal (with steel wire brush and grinding wheel), pickling rust removal, sand blasting rust removal, etc. can also be used.

(二)Reinforcement straightening

The coiled reinforcement must be placed and straightened before use, and the thick reinforcement supplied with straight bars must also be straightened once before use, so as to meet the provisions of “reinforcement shall be straight without local twists and turns” required by the specification.

The steel bar straightening machine can complete three processes of rust removal, straightening and cutting at the same time. There are five straightening blocks in the straightening cylinder of the straightening machine. They do not rotate on the same center line. The offset value shall be adjusted according to the nature of the reinforcement and the wear degree of the straightening block, so that the reinforcement can get the best straightening effect. The two straightening blocks at the inlet and outlet ends of the straightening cylinder must be adjusted to the straightening position.

When the cold drawing method (such as winch) is used to straighten the reinforcement, the cold drawing rate of grade I reinforcement shall not be greater than 4%; The cold drawing rate of grade II and III reinforcement shall not be greater than 1%. If it is used for general tensile reinforcement, the strength after tension is not used, and the cold drawing rate during cold drawing and straightening can be appropriately improved, but the grade I reinforcement shall not exceed 6%, and the grade II and III reinforcement shall not exceed 2%; For structures that are not allowed to use cold drawn reinforcement, the straightening and cold drawing rate of reinforcement shall not be greater than 1%.

(三)Reinforcement cutting

1: The reinforcement shall be cut off according to the calculated blanking length. Reinforcement cutting machine or manual cutter can be used for reinforcement cutting. The manual cutter is only used to cut the reinforcement with diameter less than 16mm, and the reinforcement cutter can cut 40mm reinforcement. When the diameter of reinforcement is greater than 40mm, it shall be cut with oxygen acetylene flame or grinder.

2: In the construction of large and medium-sized construction projects, the reinforcement cutter is advocated. It not only has high production efficiency and convenient operation, but also ensures that the end face of the reinforcement is perpendicular to the reinforcement axis without horseshoe shape or warpage, which is convenient for welding or mechanical connection of the reinforcement. The blanking length of reinforcement shall be accurate, and the allowable deviation shall be ± 10mm.

(四)Reinforcement bending forming

1: After the reinforcement is cut according to the material length, it shall be scribed according to the characteristics of bending equipment, reinforcement diameter and bending angle, so as to bend into the designed size and shape. If both sides of the bent reinforcement are symmetrical, the marking work should start from the center line of the reinforcement to both sides; When bending the reinforcement with complex shape, the real sample (full-scale setting out) can be set out first, and then bending can be carried out.

2: Steel bar bending machine or steel bar hoop bending machine should be used for steel bar bending; When the diameter of reinforcement is less than 25mm, a small amount of reinforcement (or stirrup) can be bent, or it can also be bent by manual pulling hook.

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