Formwork - Demountable
In general formwork is removed once the concrete has gained sufficient strength. Formwork should be designed (for large jobs by the Temporary Works Designer) so that it can be safely and readily erected and dismantled. The designer should make sure that the erection and dismantling of the formwork does not overload any existing temporary or permanent structures. Formwork should be erected and dismantled in a safe manner which does not compromise the safety of operatives or the structure.
Formwork is often constructed in panels to aid transportation and re-use. The weight of panels must not exceed available lifting capacity. Formwork should be designed so that it can be removed without damaging the concrete surface. The timing of removal of formwork will depend on the rate of strength gain of the concrete:
Proprietary systems are now commonly used for formwork and falsework. It is important that proprietary systems are erected, installed, and used in accordance with manufacturers’ instructions. The load capacity of formwork or falsework items can be significantly reduced if the items are damaged, bent or buckled. Thus damaged items should not be used.
Timbers or beams may be needed to spread the concentrated reactions from the base-plates on the top or bottom of props.