As a temporary supporting structure in concrete construction, formwork must be installed strictly according to the design requirements. A precisely engineered formwork system ensures that concrete structures and components are formed accurately in terms of their intended positions and geometric dimensions. During the concrete pouring process, such formwork guarantees that the concrete remains properly positioned and can effectively withstand external pressure loads. Therefore, formwork construction is of paramount importance.

How can we achieve better results through construction? Every detail matters! Below, Lianzhu Zhan brings you the construction process flow for building formwork—hopefully, it will be helpful to you!

I. Surveying and Layout

Before erecting formwork, the construction worker needs to lay out lines around each shear wall and column according to the drawing requirements, and mark each axis line, control line, and shear wall boundary line.

Next, weld along the edges of the component’s cross-section and along the cross-section control lines. Within shear walls, the spacing between cross-section control lines should be greater than 600 mm, and these control lines should be positioned approximately 6 cm above the top surface of the slab. Ensure that there are two weld lines on each side of the column.

II. Scaffolding Erection

As the supporting structure for formwork, scaffolding is a prerequisite for laying out the formwork. Typically, when erecting scaffolding, the spacing between uprights beneath floor slabs on standard floors should not exceed 1.2 m, and the spacing between supporting uprights beneath beams should not exceed 0.9 m. The bottom sweep rod must be no more than 200 mm above the floor surface, and the spacing between the first horizontal bracing members should not exceed 1.5 m.

If the slab thickness exceeds 120 mm, the story height exceeds 3 m, or the beam height exceeds 700 mm, the support system must be implemented according to a specific detailed plan.

3. Erection of bottom formwork for beams

When setting up the bottom formwork for beams, limiting fasteners must be installed on both sides. At least one limiting fastener must be provided at each end of the same span, and another limiting fastener should be installed every two small crossbars along the middle section. After completing these steps, proceed with laying the formwork panels.

4. Erection of side formwork for beams

When erecting side forms for beams, it is necessary to use tie rods or wooden clamps for reinforcement. During operation, if the beam height exceeds 600 mm or when working with side forms for edge beams, additional reinforcement with tie rods is required.

V. Erection of Formwork for Slabs

After the formwork is laid, it’s necessary to check the elevation and flatness of the formwork surface by stretching strings along the elevation lines and diagonals. Typically, a 500mm diagonal should be used for this inspection.

6. Erection of wall and column formwork

When erecting exterior wall formwork, it is necessary to extend the formwork downward by 200 mm. After completing one side of the wall formwork, template stop strips should be installed on the reinforced concrete wall panels—typically arranged in a plum-blossom pattern every 450 mm. It’s important to note that at the joints between formwork panels, three additional strips should be placed closely on both sides; one strip should be installed at the top slab level, and two more strips should be positioned midway between the beam and the wall. The wall panels between the beam and the wall should be securely clamped together using steel pipes to prevent any misalignment between the wall and the beam.

7. Template Reinforcement

The reinforcement of exterior wall columns shall adopt a combined tension-and-support approach. Reinforcing bars for tension ties shall be pre-embedded in the floor slabs, with inclined tie spacing no greater than 2 meters and positioned more than 50 cm from the edge of the wall column. At the junction between adjacent upper and lower floor columns (or walls), additional locking screws shall be installed. These locking screws shall be located 100 mm from the horizontal construction joint of the wall column, with a spacing no greater than 750 mm. Each side must have at least two locking screws.

After the formwork is erected, a quality inspection of the formwork construction is still required to ensure that all deviations fall within the allowable tolerances.

Guangxi Baimu Linmu Industry Co., Ltd. is a professional manufacturer of construction formwork.