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For removable forms, once the concrete has been poured into formwork and has set (or cured), the formwork is struck or stripped to expose the finished concrete. The time between pouring and stripping depends on the job specifications, which include the cure required, and whether the form is supporting any weight; it is usually at least 24 hours ...
An axial fan is a type of fan that causes gas to flow through it in an axial direction, parallel to the shaft about which the blades rotate. The flow is axial at entry and exit. The fan is designed to produce a pressure difference, and hence force, to cause a flow through the fan. Factors which determine the performance of the fan include the ...
In-situ evaluation of silane treated concrete cast using Zemdrain formwork liner at Dock street bridge, Belfast. Internal report to Du pont De Nemours, Luxembourg, Report No - TAS 139, June, 1992, p. 8, (Unpublished). Reddi, S.A. Permeable formwork for impermeable concrete. Indian Concrete Journal, January, 1992, pp. 31–35.
Flow table with a grip and a hinge, 70 centimetres (28 in) square. In the American version of this test, the table is 10 inches (25 cm) diameter per ASTM C 230.; Abrams cone, open at the top and at the bottom - 30 centimetres (12 in) high, 17 centimetres (6.7 in) top diameter, 25 centimetres (9.8 in) base diameter.
Like other concrete formwork, the forms are filled with concrete in 1-foot to 4-foot high "lifts" to manage the concrete pressure and reduce the risk of blowouts. After the concrete has cured, the forms are left in place permanently to provide a variety of benefits, depending on materials used: Thermal insulation; Soundproofing
For a ground-bearing slab, the formwork may consist only of side walls pushed into the ground. For a suspended slab, the formwork is shaped like a tray, often supported by a temporary scaffold until the concrete sets. The formwork is commonly built from wooden planks and boards, plastic, or steel.
Both supply and exhaust happened through an unconditioned attic space, with exhaust air being extracted at ceiling height and air being supplied at floor level through a vertical duct. The device was found to provide sufficient ventilation air flow for a single family home and heat recovery with an efficiency around 40%.
In the case of an ideal lossless fan system (i.e. =) the SFP is exactly equal to the fan pressure rise (i.e. total pressure loss in the ventilation system). In reality the fan system efficiency is often in the range 0 to 60% (i.e. η t o t < 0.6 {\displaystyle \eta _{tot}<0.6} ); it is lowest for small fans or inefficient operating points (e.g ...