Before the column formwork is installed, the axis and column edges must be played well, and the elevation should be set on the steel bar. In addition to ensuring that the column formwork and support are firm and stable, the upper and lower formwork should be supported on the same vertical line. If the construction is in winter, the ice, snow and soil on the formwork should be cleaned before the formwork is supported, and the sundries, ice and snow in the formwork must be cleaned up after the formwork is supported, and no watering is allowed. In case of strong winds (level 5 and above), the assembly and hoisting of large formwork shall not be carried out.
The back of the wall and column formwork can be pasted with 50mm thick flame retardant polystyrene board for insulation, and the relative gap of the insulation board can be increased by 1~2cm to ensure that the insulation board does not fall. And the bamboo plywood or three plywood should be disassembled and assembled at the same time as the formwork.
The beam side formwork should use 18mm thick board; the beam bottom formwork should use 50mm thick pine planing; the floor formwork of the floor should use seven plywood or 18mm thick multi-layer board. The formwork frame should be erected according to the requirements of the formwork plan, and the support elevation and the arching height should be checked after the erection is completed, and the slab formwork should be laid flush to the outer opening of the beam side formwork, and should not be laid on the beam side formwork. Key points of building formwork dismantling: When dismantling the formwork in winter, the application for dismantling should be submitted in accordance with the regulations, and the pressure test report of the dismantling test block should be included.
The correct formwork dismantling sequence and method should be selected according to the provisions of formwork design. If there are no specific provisions, it should be carried out according to the principle of first support and then dismantling, and the formwork of the non-load-bearing part should be removed first, and then the formwork of the load-bearing part should be removed.
In a positive temperature environment, the formwork can be removed if the edges and corners of the concrete and the surface layer will not be damaged due to the removal of the wall formwork; while in a negative temperature environment, the compressive strength of the demolded test block should reach 4MPa and the concrete is not affected. The formwork can be removed under freezing conditions, and the removal time should also be strictly controlled. When the temperature difference between the concrete and the outside environment is greater than 20°C, the concrete surface should be covered with polyethylene plastic sheet after the formwork is removed, and the surface should be temporarily covered with a straw bag to allow it to cool slowly.
