1． Steel strut support system
Adding a column cap (fastener) to the top of the standard steel strut prevents the main keel from displacing. The spacing of the pillars in the direction of the main keel is generally 1.2 to 2.4 m. The steel pillar system can be divided into four types due to the difference between the keel and the support, and the method of "first disassembling the mold shell and then disassembling the pillar" can be adopted. That is, when the strength of the concrete reaches 50% of the design strength, the bolt can be loosened to remove the angle steel, and the mold shell can be removed first to increase the turnover of the mold shell. The following figure is a kind of steel pillar support system, the keel wears a pin every 400mm, and the φ20mm steel pipe is buried at the pin, which is not only convenient for installing the pin, but also prevents the deformation of the main keel side in the process of pinning the angle steel.
Fig.: One of the mold shell steel pillar support systems
The angle steel is fixed to the main keel with φ18 pins as a shell support point.
The column head structure of the remaining three steel pillars, see the figure below.
Fig: Mold shell support stigma (a) channel steel; (b) angle steel; (e) square wood
2． Gantry support system
The gantry is used to form an integral shelf (pictured below).
Figure: Gantry support
Place 100mm × 100mm square wood on the top support as the main beam, and put 70mm × 100mm square wood on the main beam as the secondary beam, and set according to the spacing of the dense ribs. The angle steel of ∟50×5 is nailed on both sides of the secondary beam as a support for the mold shell (below). This kind of support system can also be used to remove the mold shell first, and then remove the rib bottom support.
Fig.: Gantry support support mold housing
3． Early dismantling of the column head support system
It is composed of pillars, early disassembly column heads, main beams, secondary beams, horizontal bracings, oblique bracings, and adjusting anchor bolts. This support system is to place an early dismantling column head on top of a steel pillar (Fig.-1). Its support system is shown in Figure-2.
Figure-1 early removal of the column head 1- truss beam; 2- column head plate; 3- pillar
Figure-2 Early dismantling system support system 1- mold shell; 2-stigma; 3-beam; 4-cantilevered diagonal brace
1． Process
The grading line → pillars, the installation of primary and secondary keels and tie rods→ the installation of support angle steel→ the placement of mold shells →
Plugging the pores → brushing release agent→ with tape to block the seam→ tie the steel bar (first tie the rib beam and then tie the plate reinforcement) to →
Installation of electrical pipelines and embedded parts→ concealment project acceptance → pouring concrete → maintenance→ dismantling angle steel support
Pneumatic disassembly mold shell → cleaning mold shell→ brush release agent, spare → dismantling horizontal support, main keel
2． Support of the mold shell
(1) Before construction, according to the design requirements of drawings, the preparation of materials and tools should be made according to the construction flow section.
(2) When the mold shell is stacked on the spot, it should be stacked into stacks, and attention should be paid to handling it gently.
(3) When the mold shell is arranged and laid, it is laid from the middle of the axis to both sides, so as to avoid the phenomenon of unequal ribs on both sides.
(4) When the main keel is installed, it should be laid according to the spacing size of the pull-through line, so that it is horizontal and vertical.
(5) Because the size of the mold shell processing is only allowed to have a negative difference, there will be a certain gap after the mold shell is laid, so it is necessary to use cloth tape to paste the gap and seal it tightly to avoid leakage.
(6) In order to prevent the mortar from flowing into the pores when pouring concrete, before applying the mold release agent, first wipe the periphery around the pores cleanly, and check whether the stomatals are unobstructed, and then use no less than 50mm × 50mm cloth-based adhesive tape to block the stomatals. When pouring concrete, it should also be supervised by a special person.
(7) After the mold shell is installed, a comprehensive quality inspection should be carried out and pre-inspection procedures should be carried out. The mold shell support system is firmly installed, and the construction load of the mold shell should not be greater than 2.5~3kN/m2. Its allowable deviations are shown in the table below.
3． Release
Due to the bowl-shaped contact surface between the mold shell and the concrete, it is difficult to manually remove the mold, and the mold shell is more damaged, especially the plastic mold shell.
Pneumatic mold removal is after the concrete molding, according to the same conditions of the site test block strength of 9.8N/mm2, with the air pump (general working pressure is not less than 0.7N / mm2) as energy, through the high-pressure leather pipe and air gun, the air into the mold shell air inlet hole, due to the air pressure, and the mold shell elastic characteristics, so that the mold shell can be intact and the concrete separation, by manual assistance to remove the mold shell. The number of mold shell turnovers has been increased from 30 to about 100 times.
4． Precautions
(1) The mold shell pillar should be installed on a flat, solid ground and should be padded through the long footboard.
(2) When the height of the pillar exceeds 3.5m, the pillars should be connected to each other with fasteners and steel pipes every 2m.
(3) When the floor construction load is greater than the calculated load, temporary support must be added.
(4) Vertical transport of mold shells and accessories should be picked up and down, and it is strictly forbidden to throw them.