1. What are the structural forms of cast-in-place reinforced concrete stairs?
There are two kinds of stairs: slab stairs and beam stairs.
Slab stairs: the bottom of the steps is flat, beautiful and easy to decorate. It is suitable for places where the load and building height are small (the building height has a direct impact on the length of stairs), such as houses and dormitory buildings.
Beam-slab staircase: It is composed of tread slab, stair inclined beam, platform beam and platform slab. It is economical to use when the load or ladder span is large, but the formwork support and construction are more complicated.
Second, the pouring method
First pour stairs and platforms, and then pour shear wall concrete before the initial setting of stair concrete. But the slump of concrete is better to be smaller, so we should pay attention to vibration and export the concrete flowing out from the bottom of shear wall.
For the convenience of construction, it is best to nail steel wire mesh at the junction of stair tread and shear wall, so that the concrete is not easy to turn up from the lower mouth when vibrating shear wall.
There is another nonstandard practice, but the look and feel is more beautiful.
Shear walls and stairs are poured in stages, that is, after the stairs, shear walls are constructed first, and stair reinforcement is reserved (pay attention to template setting-out and plate distribution), and then the stairs are constructed.
Disadvantages: the construction joint is left at the root (bearing), which does not conform to the specification (but the specification does not have to be located at the minimum shear). If the supervisor does not agree, it is bound to increase the steel dowel and node reinforcement; It is difficult to set out the steel dowel, so it is necessary to match the plate and drill the steel dowel hole first, otherwise it may not be possible to leave the steel dowel at the steel bar of the formwork steel pipe and the square wood, which will cause the steel dowel to be pulled out in the future. The cost has increased.
Advantages: the concrete pouring quality is good, the impression (flatness) is good, and the joints are clear, which is conducive to the evaluation of the main structure as a high-quality project.
In addition, the common practice of stair flight is to leave three-step (generally one-third across the flight) construction joints on the upper floor, and it can also be suggested to stay on the floor. The principle is the same as above.
What is recommended above is a special and common staircase, that is, cast-in-place reinforced concrete staircase. So how should this cast-in-place reinforced concrete staircase be installed, and what are the corresponding process steps and precautions? Interested friends can learn from the above, learn to prepare corresponding tools and materials, practice according to specific skills and suggestions, and maintain them in time later. Only in this way can we harvest waterproof, moisture-proof and anti-corrosion, cost-effective and firm cast-in-place reinforced concrete stairs.