Key points of formwork support system construction

a. In order to ensure that the formwork support system has sufficient rigidity and stability, the spacing between the timbers and the bolt reinforcement shall be constructed in strict accordance with the formwork construction design plan.

b. When making the formwork, the number and axis shall be prepared according to the specifications of each bay, so as to facilitate the assembly and disassembly.

c. In order to facilitate demoulding and ensure that the concrete surface is clean, polyurethane isolating agent shall be applied to reduce the adhesive force between the formwork and the concrete.

Quick dismantling principle: during formwork erection, use limit nuts to adjust the height of the top plate so that it is at the design elevation of the bottom surface of the structural plate, fix it with limit screws, and fix the corrugated wood formwork on the supporting plate. Use the arranged rear dismantling plate belt to reduce the longer span to within 2m. After the strength of the newly poured concrete reaches 50% of the design strength, the formwork can be removed [according to the local climate conditions, the formwork can be removed in three to four days generally].

When removing the formwork, unscrew the limit nut of the supporting plate to make the supporting plate fall down, remove the steel back edge and the formwork, and remove the plate strip after leaving it. When the concrete strength reaches 75% [when the beam span is 2-8m] or 100% [when the beam span is ≥ 8m], remove it.

The characteristics of early dismantling of frame beam formwork are that the beam support frame is provided with additional steel pipe supports at the bottom of the beam in addition to the double row steel pipe supports as usual, with a spacing of 1200mm [later dismantling]. The double row frame and beam side formwork are removed at the same time as the early dismantling plate. The additional supports and beam bottom formwork are removed when the concrete strength reaches 75% or 100%, depending on the beam span.

technological process

Setting out and snapping line -- erection of beam support -- dismantling of upright post and installation of quick dismantling head after erection -- adjustment of bracket limit nut and installation of main beam -- Installation of beam and plate formwork

Key points of construction

① After setting out the axis of the concrete slab surface, the operation team shall snap out the beam center line and the quick dismantling upright pole center line in strict accordance with the construction plan layout to ensure that the upright pole is vertical.

② The limit nuts of the quick dismantling head and the steel pipe upright and the limit nuts of the main corrugated wood bracket shall be screwed firmly.

③ The quick dismantling upright poles of the high and low floors and the additional support upright poles at the beam bottom shall be arranged on the same vertical line.

④ When removing the early dismantling flat formwork, the limit nut under the quick dismantling head shall not be loosened when the limit nut of the adjusting bracket is lowered. When removing the double row support frame of the beam formwork, the additional support at the beam bottom shall not be loosened.

⑤ The removal time of the post removal upright rod and plate strip and the additional steel support at the beam bottom shall be strictly until the concrete strength reaches 75% or 100% of the design strength.