by Installation scope of precast reinforced concrete frame structural members 1 # this process standard is applicable to the installation of precast beam, column and slab concrete members of multi-storey frames in general industrial and civil buildings.
2.
Construction preparation 2.1.
Materials and main machines and tools: 2.1.1.
Components: prefabricated reinforced concrete beams, columns, plates and other components shall have factory certificates.
The specification, model, position and quantity of embedded parts and appearance quality of components shall meet the design requirements and the provisions of standard for quality inspection and evaluation of precast concrete components (gbj321-90).
2.1.2 reinforcement and section steel: the specification and shape shall meet the requirements of the drawing, and the steel factory certificate shall be provided.
2.1.3 cement: 425 and 525 ordinary portland cement should be used.
525 expansive cement or ordinary portland cement no less than 525 should be used for column caulking.
Slag cement or pozzolanic cement should not be used.
2.1.4} stone: particle size 5 ~ 32mm., The mud content is not more than 2%.
2.1.5 # sand: medium sand or coarse sand, with mud content no more than 5%.
2.1.6 welding electrode: it must be selected according to the design requirements and relevant provisions of the current welding process.
The package shall be neat and free from rust and moisture, and the product certificate and instructions shall be provided.
2.1.7 formwork: complete preparation according to the structural requirements and required specifications, and brush the release agent.
100mm × 100mm，100mm × 50mm square timber.
50mm thick wood board.
2.1.8 main machines and tools: hoisting machinery, electric welding machine and supporting equipment, welding rod drying box, steel wire rope, snap ring, flower basket corrector, column lock hoop, sliding rope, support, plate hook, theodolite, level ruler, tower ruler, guiding ruler plate, iron shoulder pole, Jack, chain fall and crowbar.
Steel ruler, etc.
2.2 operation conditions: 2.2.1.
Familiar with drawings: fully understand and be familiar with the design drawings, especially the structural construction drawings, component processing drawings, node structure details and relevant atlas.
Carefully grasp the model, quantity, weight, node method, key points of construction operation, safety production technology, relevant regulations on high-altitude operation and the relationship between various components.
2.2.2 preparation of hoisting scheme: carefully prepare the structural hoisting scheme according to the structural characteristics and construction process requirements of the building and in combination with the actual site conditions.
And conduct safety, quality and technical disclosure to the construction personnel.
2.2.3 pre inspection of main components: according to the structural construction drawing and component processing sheet, check whether the model, quantity, specification, concrete strength, embedded iron parts, reserved joint reinforcement position and quantity of components entering the site meet the design drawings, and whether there is factory certificate of components.
2.2.4 line snapping: clean the cement slurry, rust and other sundries on the embedded parts and exposed main reinforcement.
Snap the axis (center line) on the component, that is, install the positioning line, and indicate the direction, axis number and elevation line.
The axis of the column shall be snapped on three sides.
In addition to snapping the axis, the column on the first floor shall also be marked with ± 0.00mm horizontal line on three sides.
Snap the cross center line of embedded parts.
Snap the axis at both ends of the beam, and use the axis to control the installation and positioning.
2.2.5 control the installation elevation of the floor: after the construction of the structural part of the component connection and anchorage is completed, place the axis line and elevation control line of the floor column grid, plaster the laminated layer of the upper and lower column joints, embed and level the positioning steel plate and calibrate its elevation.
The grid axis of floor column shall be clear and accurate.
2.2.6 adjust the exposed reinforcement on the upper part of the composite beam, the welded main reinforcement at both ends shall be directly embedded, and the length and position of the main reinforcement at the connection part shall be checked according to the design requirements.
Without affecting the normal installation, fasten the beam main reinforcement on the upper part of the flower basket beam, and the column head positioning embedded parts can also be welded on the reinforcement of the composite beam, but their elevation and position must be accurate.
2.2.7 the hoisting machinery selected according to the construction organization design shall enter the site and be verified by trial operation to comply with the safety production regulations.
The hoisting equipment can be put into operation only after being prepared.
2.2.8 erection of scaffold and safety protection frame: according to the provisions of the construction organization design, the hoisting operation scaffold, operation platform and safety protection facilities shall be erected on the hoisting operation surface.
After the inspection, acceptance and appraisal by relevant personnel, the formal operation can be carried out only after it meets the safety production regulations.
No operation is allowed without safety protection and safety measures.
2.2.9 place the beams, columns, plates and other components required for this floor horizontally according to the plane position.
In order to prevent the small column head from cracking or bending the main reinforcement when the column is overturned and lifted, safety outriggers can be used, or skid can be added at the main reinforcement at the column end to prevent the main reinforcement from bending and deformation due to lifting.
2.2.10 the welder shall have the operation certificate and code.
Before formal welding, the welding test must be carried out to adjust the welding parameters and provide simulated weldments.
Only those who pass the test can operate.
3.
Operation process # 3.1.
Process flow: column hoisting (correction → positioning → welding) → beam hoisting (correction → main reinforcement welding) → treatment of core area of beam column joint → shear wall construction → plate installation # 3.2.
Column hoisting: 3.2.1.
Hoisting shall be carried out in the sequence specified in the structural hoisting scheme, generally moving forward along the longitudinal axis, and flow operation shall be carried out layer by layer and section by section, Each floor starts from one end to reduce repeated operations.
When the column on one horizontal axis is hoisted, the column on the next horizontal axis is hoisted.
3.2.2 clean up the sundries at the installation part of the column, remove the loose concrete and the adhesive higher than the positioning embedded steel plate, and check whether the column axis, the position, elevation and anchorage of the positioning plate meet the design requirements..
