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Formwork shape

The type of formwork erected will depend on the shape of the element being constructed. Examples are given in the Table.

Columns Vertical bases of square, rectangular, circular or other cross-section in plan. Held vertically by props and designed to withstand the ´bursting´ pressure from the wet concrete.
Beams Long shallow rectangular open box shapes supported usually on falsework. Designed to support the self-weight of the concrete and the ´bursting´ pressure from the concrete.
Slabs Flat areas of formwork, usually supported on falsework, designed to withstand the weight of the reinforcement and wet concrete.
Walls Long, thin, deep, open box shapes, usually held by vertical props. Designed to accommodate the ´outward´ pressure of the concrete, which tends to push the two large faces apart. This tendency is usually resisted by bolts tying the two faces together through the wall. Wall formwork may need to be designed for wind loading.
Pad foundations and pile caps Open box shapes, usually in the ground, with formwork around the perimeter. Designed to withstand the outward ´bursting´ pressure from the wet concrete. External faces are kept vertical by props or struts.  


Acknowledgement: The Concrete Society


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