Concrete Formwork Svstems - Part 4 pptx

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Horizontal Formwork Systems:

Crane-Set Systems

4.1 Flying Formwork System

4.2 Column-Mounted Shoring Systems

4.3 Tunnel Formwork System

Crane-set formwork systems are typically constructed and assem￾bled as one large unit that can be moved horizontally or vertically

from floor to floor by cranes. As a result, adequate crane services

are required for handling these systems. This chapter deals with

the following crane-set formwork systems: flying forms, column￾mounted shoring system, and tunnel forms. These systems are

characterized by their high initial cost and their rapid floor cycle

time.

4.1 FLYING FORMWORK SYSTEM

Flying formwork is a relatively new formwork system that was de￾veloped to reduce labor cost associated with erecting and disman￾tling formwork. The name ‘‘flying formwork’’ is used because

forms are flown from story to story by a crane. Flying form systems

are best utilized for high-rise multistory buildings such as hotels

and apartment buildings, where many reuses are needed.

4.1.1 Flying Formwork Components

Flying formwork is available in different forms that suit the particu￾lar needs of the project. The following components are found in

most flying formwork systems available in North America and

Europe. Figure 4.1 shows a model of flying truss system compo￾nents.

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Figure 4.1 Components of flying framework.

Sheathing Panels

Flying forms usually consist of large sheathing panels that are typi￾cally made of plywood or plyform. Plywood with standard size of

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8 ft (1.22
2.44 m) allows fewer joints and produces a high

quality of concrete. The thickness of plywood used is a design

function. Figure 4.2 shows flying formwork system with a sheath￾ing panel on the top.

Aluminum Joist ‘‘Nailers’’

Sheathing panels are supported by aluminum ‘‘nailer-type’’ joists

(Figure 2.6). Each joist is a standard I beam with a wide top flange

that allows a wood nailer to be inserted to provide a wider nailing

surface for the sheathing panels. Other types of joists available are

symmetrically designed with wide top and bottom flanges that