1、 According to the requirements of design I drawing, the location of box and box is determined at brick wall, large formwork concrete wall, sliding formwork concrete wall, wood formwork concrete wall, combined formwork concrete wall, etc
.
On the concrete slab, prestressed hollow slab, cast-in-place concrete slab and precast thin concrete slab, the position and size of the lamp holder box shall be marked
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2、 Cold nestling method and hot feeding method can be used to process and prefabricate pipe bends
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The method is the same as that of open application
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When the steel pipe is bent, the bending flatness shall not be greater than 10% of the outer diameter of the pipe, and the bending angle shall not be less than 90 degrees
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3、 The box holes can be reserved for the stable burying box, or the hole can be removed for the stable burying box, and then the short pipe can be connected
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4、 Concealed pipe laying cast-in-place concrete frame pipe, especially the power line
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High strength rigid PVC pipe can be used for lighting circuit and weak current system, and steel pipe protection should be made for important parts of the structure
.
A
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Pipe laying in cast-in-place concrete column: the pipe shall be laid in the middle of the column, and bound with the main reinforcement or stirrup every LM, and the binding point at the box entrance shall not be greater than 0.3m
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When the pipe leads out of the column, in order not to extend the formwork, a sleeve is set at the pipe orifice and glued well
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The outer end of the sleeve should be tightly blocked and tightly attached to the formwork, fixed, and directly poured into the concrete
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The lamp box, switch box and socket box on the inner wall of cast-in-place concrete column shall be laid in the middle of the column
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The pipe shall be connected with the box first, and the box shall be tightly blocked with waste paper wrapped with plastic film or plastic film wrapped with sawdust or hemp rope, so as to avoid mortar penetration during pouring
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When passing through the cast-in-place concrete column horizontally, the structural strength of the column will be weakened, and the steel pipe shall be used as the casing to leave the end of the column as far as possible
.
B
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Pipe laying in cast-in-place concrete beam: when the pipe needs to cross the beam, the beam crossing position should be some distance from the beam end, and it should pass through the middle of the beam; when the pipe needs to cross the beam vertically, it is better to pass through near 1 / 3 of the clear span of the beam, where the stress of the beam is the least; when the pipe is laid horizontally and clockwise in the beam, the plastic pipe should be laid at a certain distance from the main reinforcement, and should not be laid When binding with the main reinforcement, it is necessary to ensure that there is concrete around the main reinforcement, so that the mechanical strength of the beam can be guaranteed
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It shall be laid near the middle position of the beam, at least 50 mm away from the upper part of the beam bottom reinforcement
.
C
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Pipe laying in the cast-in-place concrete wall: the pipe box shall be connected in the cast-in-place concrete wall, and the box (box) laid in the wall shall be in the reinforcement grid
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The pipe inside the cast-in-place concrete wall should take a shortcut (it does not need to be horizontal or vertical), should be laid between two layers of reinforcement, and the pipe and reinforcement should be bound firmly
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The binding point should not be more than 1m away, and the binding point should be near the box
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D
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Pipe laying in hollow brick partition wall of frame structure: when the pipe is laid horizontally in the hollow brick wall, a row of ordinary bricks can be used in the piping layer, or a section of concrete can be poured to protect the pipe
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When the hollow brick is laid horizontally, it can also pass through the hollow hole of the hollow brick
.
E
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Pipe laying of aerated concrete block partition wall of frame structure: except for distribution box, pipe laying of aerated concrete block partition wall shall not be embedded with wall laying
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Other appliance wire boxes and pipes shall be grooved and laid after wall laying
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F
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Laying of pipes in cast-in-place concrete floor: after the formwork of cast-in-place concrete floor is erected and before the reinforcement is placed, electricians shall snap the cross line according to the edges of walls and beams around the room to determine the accurate position of the light position
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When the bottom reinforcement of floor is bound and padded, piping shall be carried out before the surface reinforcement (some are called cover iron) is bound
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The pipeline shall be laid between two layers of reinforcement, and then the surface reinforcement shall be bound after piping
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Short cut should be taken for pipeline laying, and it is not necessary to be parallel and vertical to each other
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The outer diameter of the pipe should not exceed 1 / 3 of the thickness of the concrete slab, and the pipe and the concrete surface should not be less than 15mm, otherwise the floor is prone to cracks
.
G
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Pipe laying of precast hollow floor slab: the pipe of precast hollow floor slab can be laid in the slab joint or slab hole in a concealed way, and the pipe can not be laid horizontally
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The light point box should also be buried in the slab joint (DF type) as far as possible
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If the light point is not the slab joint, the hole burying box can be removed in the slab hole (ordinary lamp holder box is used), but the slab rib cannot be removed
.
H
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Pipe laying in the cushion (post pouring layer) of the floor (roof): the thickness of the cushion (post pouring layer) shall be able to protect the pipe, the minimum thickness of the protective layer of the pipe shall not be less than 15mm, and the uneven part of the floor (roof) shall be leveled
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When piping inside the floor (roof) scorched slag cushion (other insulation layer), the surrounding of the pipeline shall be protected with cement mortar with a thickness of not less than 50 mm before the cushion construction, so as to prevent the pipeline from mechanical damage
.
1
.
Laying of pipes in balcony and awning board: the stress of cast-in-place concrete balcony and awning board is that the upper part is under tension and the lower part is under pressure, so the steel mesh is set in the upper part
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When laying pipes in balcony awning board, it should be carried out after the bottom formwork is erected and before the steel bar is bound
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Connect the pipe with the light box, block the box tightly and fix it firmly with the formwork, pad the pipe on the formwork with a height of at least 15mm, when using the wood formwork, nail the light box on the formwork with nails, keep a certain distance between the pipe and the reinforcement and bind it tightly
.
J
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Pipe laying in the ground: generally, the pipe is laid in the concrete cushion, and the cushion is tamped and leveled before laying
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For pipes laid in the ground, the height of pipe orifice exposed to the ground should not be less than 200 mm, and it should be vertical to the ground
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The exposed section should be protected by steel pipe, and the buried end of steel pipe should be sawed into a 30 – 45 degree angle to increase the underground fixed length
.
K
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When the pipeline passes through the deformation joint (settlement joint) of the building, the junction boxes should be embedded on both sides as compensation devices
.
50
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Pipe grounding, pipe to pipe, pipe to box should be electrically connected
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When the steel pipe (thickness not less than 2mm) is connected by screw thread, the round steel with diameter not less than 6mm shall be used for welding
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Galvanized steel pipe can not be welded, but can be crimped with copper wire of not less than 4m m2, with special grounding crimping clip
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5、 After the pipeline is laid, the pipeline shall be cleaned in time, the pipe orifice shall be blocked, the box orifice shall be sealed, and the pipeline shall be threaded after the completion of civil engineering..
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