When the diameter of the tensile reinforcement is d >; 25mm, and the diameter of compressed steel bar is d & gt28mm, so binding lap joint is not suitable. The lap length of steel bar is the lap length of steel bar binding connection, which is not strictly the weld length of steel bar welding.
When the percentage of binding joint area is between 25% and 50%, the values in the table are multiplied by the coefficient1.2; When the percentage of binding joint area is greater than 50%, the values in the table are multiplied by the coefficient1.35; When the minimum lap length is the lap length of two steel bars with different diameters, it shall be calculated according to the diameter of the thinner steel bar.
Extended data:
Relevant requirements for steel bar lap joint stipulate that:
1, when the main reinforcement is grade I reinforcement, it should not be less than 1.2 times of the cross-sectional area of the main reinforcement; When the main reinforcement is Grade II and III reinforcement, it should not be less than 1.5 times of the cross-sectional area of the main reinforcement.
2, in order to facilitate welding and make the center line of the reinforcement and the main reinforcement in the same plane. The slats shall be made of steel bars of the same grade and diameter as the main bars. If the batten is different from the main reinforcement, it should be converted according to the design strength, and the length of batten should meet the corresponding weld requirements.
3. When the design requires it, the welded joint shall adopt double-sided weld, and when there is no special requirement, single-sided weld can be adopted. The total length of lap welding or side welding of Class I rebar shall not be less than 8d.
Baidu Encyclopedia-Rebar Lapping