Manufacture and Welding Method of Wire Cages

Manufacture of wire cages

1. Material Requirements: rebar must have the certificate of qualified exit and quality assurance certificate. Rebar should be stacked separately according to specifications, models and batches. Take samples to inspect by witness according to regulations. Supervising units and construction units should be invited to witness and take samples together on the spot. The inspecting results should be notified in writing to the technical person in charge and submitted to the Supervising List. The rebar can be processed and manufactured only after it has been approved by supervising units. The site of rebar stacking requires listing for inspection, and clearly marked inspected qualified words.

2. The reinforcement hoop and spiral hoop should be made according to different piles one by one before making the wire cage. The main reinforcement should be welded by overlapped electric arc. The process should be operated on the ground. And it can be used only after the inspection and approval of the approved batch.

There are two ways to weld wire cage at construction site.

The first is overlap welding by wire cage welding machine, which belongs to arc welding. Overlap length should be meet the requirements of design specifications, one-sided welding length should be the 10 times of the rebar diameter d, two-sided welding length should be 5 times of the of the rebar diameter d.

The second is electroslag pressure welding by wire cage welding machine, which is butt welding. If do not need welding method, use sleeve connection.

The following is the specification for welding quality of wire cage.

1. When welding, starting arc shall be carried out on the backing plate, the bar or the part where the weld is formed, and the main bars shall not burn the main rebar.

2. The welding ground wire should be closely contacted with the rebar.

3. The slag should be cleared in time during welding, the surface of the weld should be smooth, the residual height of the weld should be transited smoothly, and the arc pit should be filled.

4. Make a certain bending by wire cage welding machine at the lap joint of the two main rebars to ensure that the two main rebars' axes are in the same line; the deviation of the axes should be less than 0.1D.

5. The surface of the weld seam should be smooth, and there should be no holes or weld nodules; there should be no cracks visible to the naked eye in the area of the weld joint; the depth of undercut, porosity, slag inclusion and other defects should not appear.