Welding of reinforcement bars is a practical means of developing the force transfer required in many connection. The following recommendations should be followed when welding reinforcement to avoid damage to the bars and to provide the required force transfer:
- Carbon content of the bars should not be more than 0.5 percent.
- Use only low hydrogen electrodes AWS class E7015 or E 7016.
- Do not weld within 8 inch of any cold bend.
- When pre-heating is required, the surface where the weld is being deposited must be at or above the required pre-heat temperature. Preheat for a distance of 3 inch in all directions from the point of welding.
- Tack welding of reinforcing bars in connections should not be permitted unless indicated by the design.
Design of Welding for Reinforcement:
The ultimate strength of reinforcement welds is determined by:
= tensile capacity of the weld
= length of the weld
= thickness of the weld at the throat
Typical weld details of reinforcement bars is shown in figure below:
Fig: Welded cross bar anchored
Fig: Reinforcement welded to plate or angle
Fig: Reinforcement bars welded together