How to arrange the beam and slab reinforcement under the foundation, and is the slab gluten above or below the beam reinforcement?

Top flat beam slab raft foundation (down-turned beam), slab gluten is below beam reinforcement. The slab gluten is below the beam gluten, because for the beam-slab cushion foundation, it is calculated according to the inverted floor model, and the foundation reaction is added under the slab bottom as a uniform load, so its function is opposite to that of the normal floor, so the upper reinforcement of the basement floor is placed under the foundation beam gluten as the longitudinal stress reinforcement in the slab, while the lower reinforcement of the floor is used as the negative reinforcement.

General requirements of beam-slab reinforcement binding construction in building engineering;

1. When the longitudinal steel bars are arranged in double layers, short steel bars with a diameter of ≥25mm or more should be padded between two rows of steel bars to keep the design distance. ?

2, stirrup joints (hook lap) should be staggered on two vertical reinforcement, the rest on the same column. ?

3. The steel mesh binding of the slab is the same as that of the foundation.

It should be noted that if it is the bottom plate supported by the pile cap beam, it depends on how the calculation model is obtained, and it must be analyzed according to the specific situation.

Extended data:

Reinforced concrete beam-slab structures, such as floors, roofs, balconies, awnings and stairs, are widely used in buildings. In the special structure, the roof and floor of the pool and the flat foundation of the chimney are also beam-slab structures. Reinforced concrete floor is the main component of building structure. For 6 ~ 12-story frame structure, the steel consumption of floor accounts for about 50% of the total steel consumption.

For mixed structures, the steel consumption is mainly in the floor. Therefore, the rationality of floor structure selection and layout, and the correctness of calculation and construction are of great significance to the safe use of buildings.

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