Precast concrete members have columns, internal and external walls, bay windows, beams, stacked panels and balcony panels.
1. Buried parts
The prefabricated components should be hoisted with standard hangers and hangers with embedded rings or built-in connecting steel nuts.
2. Hoisting mode
The prefabricated members are of different sizes. When the prefabricated members are too large and too wide, the multi-point lifting method can be adopted, and the adjustable beam can be used to balance the lifting position. The resultant force of the lifting point should coincide with the center of gravity of the components.
The lifting operation of vertical members should be operated slowly, rapidly and slowly.
The main girder should be hoisted before the secondary girder is hoisted, and the main girder must be corrected before the secondary girder is hoisted. Selecting the steel beam shoulder pole for hoisting, the sling must correspond to the lifting rings on the prefabricated composite beams.
It is advisable to maintain hoisting balance for lifting members of laminated plates. The lifting point should not be less than 4 points.
The prefabricated staircase components ensure that the prefabricated staircase rest platform maintains a horizontal state during the lifting process. The adjustable horizontal suspension beam is used to balance the lifting position. The lifting points must be four or more.
The prefabricated balcony slab should be hoisted with special shaped steel flat pole. When hoisting, the horizontal angle between rope and shaped steel flat pole should be 55 ~65.
The horizontal angle between the rope and the prefabricated air conditioner plate should be 55 degrees ~60 degrees when the air-conditioning board is hoisted.
3. Operating procedures
According to the code for construction of concrete structures, the lifting of precast members shall meet the following requirements:
(1) Hangers and hoisting equipment shall be selected according to the shape, size, weight and operation radius of prefabricated components, and the hoisting equipment and construction operation shall conform to the relevant provisions of the relevant national standards and product application technical manual;
(2) Measures should be taken to ensure that the main hook position of lifting equipment, hanger and component center of gravity coincide in the vertical direction; the angle between the sling and component should not be less than 60 degrees, not less than 45 degrees; the lifting process should be stable, there should be no deviation and large amplitude swing;
(3) In order to ensure the hoisting safety of prefabricated components, the cables and wind ropes should be installed on the components to control the rotation of the components to ensure the stability of the components. In site operation, two symmetrical cables and wind ropes are usually installed on both sides of the root of the component. Before approaching the installation position, the component is slowly pulled to the floor on both sides, and then stationary in place.
(4) In the course of hoisting, special person should be set up to direct, the operator should be in a safe and reliable position, and no one should hoist with the prefabricated components.