Residential building reinforced concrete monolithic plate staircase pouring construction joint

It should be perpendicular to the inclined plane of the inclined plate, because the concrete components are compressed on one side, and the other side is tensile "reinforcement", if the construction joint is not perpendicular axis, the pressure will be decomposed into two directions at the inclined plane, and the force of the seam surface slip is generated, which is unfavorable to the stress of the component, no need to find a basis, the data can not be had, and they can understand and analyze.

Friends, you don't have to investigate whether it is perpendicular to the ground and perpendicular to the formwork, it is certain that the staircase construction joint must be left diagonal.

Addendum: Regarding your question, to be honest, I have also checked a lot of relevant specifications and various related articles on the Internet in the past two days. It is certain that the current code does not clarify the problem of retention of staircase construction joints.

Personally, I think that how to prove that the practice of perpendicular to the template is correct, we can only explain it from the rationality of mechanics. Alas, my level is limited, so I won't say much.

It can neither be said to be perpendicular to the formwork, nor perpendicular to the ground, but to form a 45° oblique stubble with the formwork of this run.

Correction: I'm really sorry, the front one is a bit abrupt and almost misled you. At the same time, the reply was late due to the late addition of your question.

Here, I apologize to you and the netizens downstairs. At the same time, I would also like to thank you for your timely reminder, which has deepened my understanding of this issue. The question you asked is only based on the impression of the individual practices of the construction site, and has not been carefully considered.

This is not a responsible attitude, and I will pay attention to overcoming it in the future.

After checking the "Construction Manual" (my version is older), the reinforced concrete construction process is related to the problem of retention of construction joints, and the construction joints of the floor slab are required to be perpendicular to the floor, and it is not appropriate to leave oblique stubble. I didn't find a specific statement about the staircase, and I think it should also be implemented according to the construction joint retention method of the floor slab, which is perpendicular to the formwork.

I don't know if it's right or not, please correct it with everyone.

Cast-in-situ steel concrete Zhengwu soil floor slab: a noisy or solid slab with solid finger solidity, durability and good fire performance.

According to the current specification and there are no particularly strict regulations, according to the GB50204-2002 standard clause: "the location of the construction joint should be determined according to the design requirements and construction plan before the concrete is poured", so the best way to resolve the dispute is to prepare the construction plan before construction, clarify the location of the construction joint and report to the supervisor for confirmation.

According to the provisions of the specification article "it is advisable to leave it in the part of the structure that is less shear and convenient for construction", it should generally be left in the position of three steps up or three steps down the stair step. In the cast-in-place concrete structure, the walls on both sides of the stairwell are mostly cast-in-place concrete walls, and the staircase and the wall can not be constructed at the same time, which brings difficulties to the retention of the staircase construction joint. The following points are put forward for the retention of staircase construction joints:

One. If the frame structure or the partition wall on both sides of the stairwell is built, the stair construction joint should be left at the upper or lower three steps of the stair tread according to the requirements of the code.

Two. When the stairwell on both sides is a cast-in-place concrete wall, the construction joint of the staircase should put half of the stair beam, that is, all the 1 3 to 1 2 places of the stair beam and the rest platform, all set aside without pouring concrete, and the specific requirements are:

1. 1.When the lower shear wall is poured concrete, the beam socket of the stair beam should be left on the wall of the upper running side.

2. 2.When pouring concrete down the staircase, the stair beam of the rest platform is only poured to half, and the part of the stair beam that runs up is not poured, and the construction joint is left in 1 3-1 2 places of the rest platform on the side of the staircase.

3. 3.Do not pour concrete.

4. 4.When the concrete is poured on the floor, the foam block must be plugged into the bearing of the shear wall to leave the beam socket at the support of the shear wall.

5. 5.When running the stair formwork, the surface of the construction joints at the stair beam, rest platform and stair beam support should be chiseled and cleaned to expose the stones.

6. 6.When the concrete is poured on the stairs, the joint is watered and wet, and the next part is finely compacted with the concrete with the stone-free mortar to form a whole.

Three. If it is treated as a superimposed beam, the beam is hit to the bottom of the rest platform or the bottom of the floor slab. This practice must be handled strictly in accordance with the requirements of the superimposed surface.

Four. In the slab staircase, when the tread is supported on the shear wall on both sides as a stressed plate, the construction joint can be thrown at any position parallel to the tread plate.

Pick up upstairs. Just leave two and a half units, vertically.