1, the two refer to different places: gluten is on the upper part of the cast-in-place slab, the hook is downward in X direction and right in Y direction; The bottom bar is at the lower part of the cast-in-place slab, and the hook in X direction is upward and the hook in Y direction is left.

2. Their functions are different: the bottom reinforcement of two-way double-layer steel bar has the following functions: shear resistance, stress resistance and crack resistance; The gluten functions of two-way double-layer steel bars are: shear resistance, stress resistance and crack resistance.

If the bottom reinforcement of the cast-in-place slab on the drawing is hooked with135, the reinforcement level is generally secondary and tertiary reinforcement or ribbed reinforcement. In actual construction, it is straight reinforcement without hook, and the hook with135 is the cutting point of reinforcement. And steel bars should be hooked with 180 degrees, mainly used for bottom bars. The protective layer of gluten and bottom reinforcement is the same, generally15 mm. ?

When arranging double-layer bidirectional reinforcement, the short-direction reinforcement at the bottom of the plate should be placed in the lower part and the long-direction reinforcement on it; For the surface reinforcement, the short direction reinforcement should be placed at the top, and the long direction reinforcement should be below the short direction reinforcement. Generally, it is not necessary to set negative slab reinforcement when double-layer bidirectional reinforcement is set.

Extended data:

Double layer Because the board has a certain thickness, a layer of steel bars is used at the top of the board and a layer of steel bars at the bottom of the board. This is a double layer. Two-way is the longitudinal and transverse reinforcement of bottom reinforcement and gluten, that is, the reinforcement is arranged in the X and Y directions of bottom plate and panel, and each layer of reinforcement is in both longitudinal and transverse directions.

The steel mesh pieces of the plate and the wall shall be fastened alternately at the intersection point of the middle part, but the stressed steel bars shall not be displaced. Two-way stress steel mesh, all must be fastened; In addition to the design requirements, the stirrups of the steel bars of beams and columns should be set vertically to the stress bars. Plate, the intersection of secondary beam and main beam, the steel bar of plate is above, the steel bar of secondary beam is in the middle, and the steel bar of main beam is below; When there is a ring beam or cushion beam, the reinforcement of the main beam is on the floor.

Baidu Encyclopedia-Two-way Double-layer Reinforcement

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