March 15 2019 0Comment

Formwork Engineering And Quality Control (VII)

BOFU plastic formwork system

Key points of formwork engineering construction quality control

  1. The periphery of the formwork should be flat and straight, the joints should be tight, the height difference of the joints should be no more than 2mm, and the flatness should be no more than     3mm. The formwork should be checked and accepted before pouring concrete.
  2. The formwork and the bracket must have sufficient strength, rigidity and stability. When installing and pouring concrete in concrete forms, the formwork and its supports should be observed and maintained. When an abnormal situation occurs, it shall be handled in time according to the construction technical plan.
  3. When installing the upper formwork of the cast-in-place structure and its support, the lower floor should have the carrying capacity to carry the upper load or erect the support. The columns of the upper and lower supports should be aligned and the pads should be laid.
  4. The joint of the formwork panels should not be fiber. Before the shallow concrete, the wooden mold should be moistened with shallow water, but the formwork does not bribe.
  5. The contact surface between the formwork and the concrete should be smooth and painted with a release agent, but no release agent that affects the structural properties or hinders the construction of the decorative works.
  6. Pairs of cast-in-situ reinforced concrete beams with span more than 4m and beams with external elongation greater than 2.0m, the formwork should be according to the design requirements. The height of the arch should be 1/1000-3/1000 of the span. Large span should be large, small The span takes a small value (the span length of the cantilever beam is twice the outer elongation), and the plate with a span greater than 4 m is arched L/400 according to the plate.
  7. The formwork and support must have sufficient strength, rigidity, stability and precision to ensure the geometrical dimensions and elevation of the components. The surface of the formwork is flat and the seams are tight.
  8. Pre-construction formwork, support detailing and construction steps (including demoulding) shall be reviewed and signed by the project technical person in charge. The key parts, especially the support of large space and large span parts, shall be checked and reported to the company’s chief designer for approval. It can be implemented at the rear to ensure its safety.
  9. The floor structure formwork and the removal of the support shall be demolished after the floor has reached the specified strength. The removal of the special formwork shall be subject to the approval of the project technical person in charge and the supervision of Party A.
  10. When the beam height is greater than 600mm, 14 pairs of pull bolts are added, and the pull bolts are made by round steel on-site processing. All frame column formworks require careful correction of the verticality and temporary holes are reserved at appropriate locations for cleaning and inspection.
  11. In the construction of concrete structures, where the joints of columns, walls and masonry are required according to the design requirements, in the vertical direction of the wall, anchored into the column and wall is not less than 700mm, and the outside of the column stirrups is tied. 6 steel bars, the upper and lower spacing is 200mm for demoulding. The masonry is welded before construction, and the welding length is implemented according to the requirements of single-sided welding.
  12. Reinforced concrete columns connected to the ring and the beam, the wall shall be placed in the circle and the longitudinal reinforcement of the beam shall be ribbed, and the anchored into the column shall not be less than 35d, and shall protrude from the wall and be not less than 700mm outside the column.
  13. The bottom of the column mold must have a cleaning hole to facilitate the cleaning of garbage.
  14. The acceptance of the formwork project focuses on the control of stiffness, verticality and flatness, paying particular attention to the correct position of the template axis at the peripheral formwork, column formwork, elevator shaft, stairwell, etc.
  15. Before installing the column formwork, a steel bar with a diameter of not less thanΦ10 must be added at its root (concrete guide wall is strictly prohibited) to ensure its correct position. The lower part of the formwork is leveled with 1:3 cement mortar to ensure the uniformity of the formwork elevation.
  16. The debris in the formwork before pouring concrete should be cleaned up.
  17. For embedded parts fixed on the formwork, the reserved holes shall not leak slurry, and the annual solid shall be installed, and the deviation shall comply with the regulations.

to be continue…

BOFU plastic formwork system