What kind of quality problems occur when the buried depth of conduit is too large or too small in bored pile construction? Please specify.

1. Buried too deep. Due to the small height difference between the concrete in the conduit and the concrete in the pile hole outside the conduit, the concrete pouring is not good, the rising distance of the concrete outside the conduit is too large, and there are more and more impurities.

2. If the buried depth of the conduit is too small, the jacked concrete will contact the water surface quickly during the jacking process, which is easy to cause the concrete to "bathe".

Before pouring, the garbage, dirt, oil stains and other sundries in the template should be removed, and whether the cement mortar pad and plastic pad of the steel bar are well padded should be checked.

If wooden formwork is used, it should be watered to make the formwork moist, and the column formwork should be closed to clean the mouth after removing sundries and accumulated water.

Extended data:

Precautions:

1, when concrete is poured into the formwork, it is not allowed to impact the formwork or steel skeleton in a centralized way. When the pouring height is more than 2M, it should be cut with a string tube and a chute, and the free falling height from the discharging nozzle to the pouring layer should not be greater than1.5m. ..

2. Concrete must be poured within 5 hours (from the start of the train). In order to prevent cold joint during concrete pouring (cold joint refers to the construction quality joint formed when the time interval between the upper and lower layers of concrete pouring exceeds the initial setting time), the concrete pouring time for two times shall not exceed 65438 0.5 hours, and the joint shall be continuously stirred with a vibrating rod.

3, in the process of pouring, vibrating duration should make the concrete surface appear laitance, no bubbles, no sinking. The insertion points of vibrators are arranged evenly in plum blossom shape, and move in the order of determinant, and the distance of moving position should not be greater than 40CM. Make sure there is no vibration leakage, but no vibration.

4. When pouring beam slab concrete, beam concrete should be poured first, starting from the beam-column joint, so as to ensure the vibrating compaction of the beam-column joint, and then circulating pouring with the slab by grouting method, but no cold joint is allowed.

5. When concrete pouring is about to be completed, estimate the remaining concrete quantity and the remaining concrete quantity, and contact the mixing station for reasonable scheduling.

6. After concrete pouring is completed, scrape the surface with a scraper, and then roughen it with a brush (roughening treatment: cement mortar is made from cement and concrete interface treatment agent, and the above cement mortar is smeared on the wall surface with a roughening roller or broom to form a prickly protrusion, and then it is roughened after drying.

The main function is to strengthen the adhesive ability; At present, the walls of rough houses can be pasted with bricks without napping, but it depends on the specific situation. If the wall is smooth, it needs to be brushed. )

7. The concrete surface shall be covered in time after being plastered twice and three times. After the final set of concrete, it should be fully wetted with water, sealed and covered with plastic film, and the surface of plastic film should be checked frequently, but when there is no water drop on the surface of the film, water should be sprayed again.

The curing time from the 3rd floor underground to the interlayer roof is 7 days, and the curing time of the underground 1 floor roof is 14 days.

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