Erect Formwork, Place Inserts, and Reinforcement

The method and sequence of erecting formwork may vary de­pending on the availability of lifting equipment and whether rein­forcing cages are available. Forms are usually handled manually, by small derrick, or by crane. The erect formwork activity includes the process of lifting, positioning, and aligning the different form­work elements. This activity also includes the process of applying the form release agent or coating that prevents bonding of con­crete to forms. The concrete life cycle starts after the erect form­work activity is finished with placing inserts and reinforcement activity. The logical sequencing of erecting formwork and its rela­tion to placing inserts and reinforcement is:

1. Set lines—a template is generally set in place on the floor slab or footing to accurately locate the column floor

2. Erect scaffolding

3. Install column reinforcement

4. Provide forms for column

5. Erect outside forms for walls

6. Install wall reinforcement

7. Erect inside forms for walls

8. Install ties

9. Подпись: Copyright © Marcel Dekker, Inc. All rights reserved.Provide bracing for walls

10. Erect forms for beams

11. Install beam reinforcement

12. Erect forms for slabs

13. Place inserts for mechanical and electrical connections, openings for ducts and conduits, and supporting bars for reinforcement

14. Place secondary and main reinforcement

Figure 1.3 shows inserts and reinforcement installed above the forms.

A form coating or release agent is often applied to the inside surface of formwork to prevent the concrete from bonding to the formwork elements. Coating can be applied by spraying, brushing, or by a roller. Form coating facilitates the operation of removing the formwork after the concrete has gained enough strength to support itself. Another function of the formwork coating is sealing the surface of the wooden elements which prevent the water in freshly placed concrete from being absorbed by wood. Form re­lease agent should not affect or react with the finished concrete in any way.