Precautions for formwork removal
General provisions for formwork
Before formwork construction, the formwork shall be designed according to the structural characteristics of the building and the concrete construction process, and the safety technical measures shall be prepared.
The formwork and support shall have sufficient strength, rigidity and stability, and can reliably bear the dead weight, lateral pressure, load and wind load of the newly poured concrete during construction. The fabrication of various material moulds shall comply with the provisions of relevant technical standards.
Steel pipe, portal frame, section steel, standard section of tower body, wooden pole, etc. should be used as formwork support materials. The material of formwork support shall comply with the provisions of relevant technical standards.
The supports of various formworks shall be self-contained and shall not be connected with the scaffold.
The base plate shall be set at the bottom of the formwork support pole, and bricks and brittle materials shall not be used for bedding. The supports shall be connected to the building structure at both ends and in the middle.
When the formwork support upright is installed, horizontal support shall be added. When the height of the upright is greater than 2m, two horizontal supports shall be provided. When the height increases by 1.5-2m, another horizontal support shall be added.
In addition to vertical and horizontal two-way horizontal supports must be set around and in the middle of the full formwork pole, when the height of the pole exceeds 4m, a horizontal diagonal bracing shall be set every two steps.
When multi-layer formwork is adopted, the vertical poles of the upper and lower layers shall be kept on the same vertical line.
For the formwork requiring secondary support, there shall be no construction load on the formwork when the secondary support is installed.
The formwork support shall be installed according to the design drawings. After installation, it shall be confirmed that it meets the requirements before pouring concrete.
The stacking and equipment load on the formwork shall be strictly controlled. When the trolley is used for transportation, the trolley transportation channel shall be set up to transfer the load to the building structure.
The formwork support removal must be approved by the project leader and the concrete strength report.
The formwork removal sequence shall be carried out according to the design scheme. If there are no regulations, the main bearing formwork shall be removed first and then the secondary bearing formwork shall be removed.
When removing the column under the beam with a large span, it shall be removed from the middle of the span to both ends. When removing the multi-storey floor column, the lower column can be removed only after confirming that the upper construction load does not need to be transferred.
When there are more than two horizontal supports, more than two horizontal supports shall be removed first, and the bottom large cross bar and vertical bar shall be removed at the same time.
The formwork shall be removed step by step according to the regulations, and the method of large-area prying down is not allowed. The removed formworks, supports and connectors shall be slid down with grooves or tied down with ropes. No Suspended Formwork shall be left.