It’s important while concreting you must to choose the best formwork for many reasons and we brought you Selection of Type of Formwork.
Formwork for use under water must:
• support the concrete in its designed profile during the plastic phase
• protect the concrete from scour, washout and abrasion until it has hardened
• be able to withstand static and dynamic loading due to concrete, tides, waves and currents
• tolerate inaccuracies in formation level or alignment of adjacent work
• be easily fixed into position.
It may be designed as part of the permanent works and be left in place or as temporary works either to be left in place or struck and reused.
Formwork intended to form part of the permanent structure will generally be steel or concrete, although more modern materials such as glass-reinforced cement or glass-reinforced plastic and traditional materials such as some hardwoods may have an appreciable useful life under water.
Temporary formwork designed to be struck and reused may be made from any economic and easily worked material, timber, steel and GRC/GRP being the most common. Formwork to be left in place but not having any permanent function may be made from any stiff material, e.g. steel or timber, or from flexible fabrics.
Common forms of permanent formwork are masonry, concrete block work, concrete bag work, steel sheet piling and precast concrete panels. Unless such formwork is so massive as to be self-supporting it will require some system of support until the in situ concrete has been placed and gained strength. Concrete block work and masonry are usually keyed to the concrete heating by laying alternative stretcher and header courses; concrete panels and steel sheet piles should be anchored to the in situ concrete by means of hook bolts or ties.
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