1. According to the design requirements, the welding method of the engineering reinforcement connection is selected. The welding methods are mainly arc welding and flash butt welding, and arc welding is the main method.
2. Prior to welding construction of steel bars, rust spots, oil stains, and debris on the surface of steel bars, steel plate welding areas, and the areas where steel bars are in contact with electrodes should be removed. When the end of the steel bar is bent or twisted, it should be straightened and cut off.
3. For flash butt welding and arc welding of ribbed steel bars, longitudinal ribs should be placed and welded to longitudinal ribs.
4. The flash butt welding of steel bars should be selected with appropriate adjustment of elongation, firing retention, upset forging retention, and transformer stages. After the process parameters are determined, they should not be arbitrarily changed.
5. The arc welding of this project adopts the form of lap welding. When the conditions of lap welding are not available, strip welding is adopted. The following requirements shall be met during welding.
① When welding, the arc striking should be carried out at the side bars or welds, and the main tendons must not be burned.
② The welding ground wire should be in close contact with the reinforcing steel.
③ The slag should be removed in time during welding, the surface of the weld should be smooth, and the welding pit should be filled up.
④ The joint should be welded on both sides. When conditions are not available, single-sided welding can be used.
⑤ When lap welding, the axis of the two connecting bars should be the same. The length of the double-sided weld shall not be less than 5d, and the length of the single-sided weld shall not be less than 10d.
⑥ When welding the bars, the diameter and grade of the bars should be consistent with the welded steel bars. The length of the double-sided weld bars should not be less than 5d, and the weld length of the single-sided welds should not be less than 10d. , The end gap of the main bar should be 2-5mm.
⑦The height of the weld shall be equal to or greater than 0.3d and not less than 4mm, and the width shall be equal to or greater than 0.8d and not less than 8mm.
⑧The joints for lap welding and bar welding shall be visually inspected one by one. The surface of the weld shall be smooth and free of defects such as cracks, slag inclusions and large welding knobs.
⑨In any weld length section, there must not be two joints for the same rebar, and the cross-sectional area of the joints in the tensile zone of the stressed reinforcement in this section shall not exceed 50% of the total area.
