(1) quality problems and phenomena

The length of the weld seam is not enough, uneven surface, sag, large overlap, weld undercut, unqualified welding electrode, skin not knocking out two joint reinforced axis is not consistent.

(2) reason analysis

The welder is not skilled, no welder examination certificate.

After welding, the length of the weld is not measured.

Welding rod is not qualified, or selection of welding rod specifications.

The welding is completed, do not pay attention to welding skin off.

The two steel welding, the joint end pre bending.

(3) preventive measures

Before welding, the welding test must be carried out according to the construction condition. The welder must have the test certificate.

Welding or arc welding of steel bars shall be made as far as possible.

When the welding arc welding is adopted in the steel bars, the two steel bars should be bent to one side in advance, so that the two joints of the steel bars are in line with the axis of the reinforcing steel bars.

The joint double length should not be less than 5D, single side weld length should not be less than 10d (d bar diameter).

The reinforced joints with the help of arc welding, help should be adopted for the main steel bars in the same level, the total cross-sectional area should not be less than the cross-sectional area of the weld was reinforced. To help strip length, such as the use of double-sided welding should not be less than 5D, such as the use of a single side should not be less than 10d (d diameter).

When the electrode, its performance shall be in accordance with relevant provisions of low carbon steel and low alloy steel welding standard.

The stress of welded steel should be set up in the internalforce is small, and the staggered arrangement arc welding and the bend position and the distance of not less than 10 times the bar diameter, the maximum bending is not located in the member from the office.

9 when welding welding site should have the appropriate wind, rain, snow, cold facilities, environmental temperature at 5 ~ C ~ -20 ~ C, technical measures should be taken. Less than -20 ~ C, not.

The welding is completed, will be timely welding skin off.