Concrete Formwork Svstems - Part 6 docx

6

Vertical Formwork Systems:

Crane-Dependent Systems

6.1 Introduction to Vertical Formwork Systems

6.2 Conventional Wall/Columns Forming Systems

6.3 Ganged Forming Systems

6.4 Jump Forms

6.1 INTRODUCTION TO VERTICAL FORMWORK

SYSTEMS

Formwork development has paralleled the growth of concrete con￾struction throughout the twentieth century. As concrete has come

of age and been assigned increasingly significant structural tasks,

form manufacturers have had to keep pace. Form designers and

builders are becoming increasingly aware of the need to keep

abreast of technological advancements in other materials fields in

order to develop creative innovations that are required to maintain

quality and economy in the face of new formwork challenges.

Formwork was once built in place, used once, and subse￾quently wrecked. The trend today, however, is toward increasing

prefabrication, assembly in large units, erection by mechanical

means, and continuing reuse of forms. These developments are in

keeping with the increasing mechanization of production in other

fields.

Vertical formwork systems are those used to form the vertical

supporting elements of the structure—columns, core walls, and

shear walls. The functions of the vertical supporting systems are

to transfer the floor loads to the foundation and to resist the lateral

wind and earthquake loads. Consequently, the construction of ver￾tical structural elements precedes flat horizontal work. Typical

vertical formwork systems utilized in construction include conven￾tional formwork, ganged forms, jump forms, slipforms, and self￾raising forms.

Formwork systems for vertical concrete work can be classi￾fied into two main categories, namely, crane-dependent systems

and crane-independent systems. Gang formwork and jump form