Graduation forests
The formwork is essentially auxiliary temporary weapons with a very short service life, measured literally days. Depending on the type of concrete structures, concreting method (with or without vibration) and air temperature, concrete is kept in formwork from 1 to 28 days, and with rapidly solid concrete, these periods may still be reduced.
However, the cost of this temporary structure reaches -35% of the total cost of the structure, and labor costs for the formwork device are 30-40% of the need for the entire reinforced concrete structure. If we add to this that reinforced concrete is consumed on average up to 0.3 m3 of wood, but it becomes completely clear that the matters of the reduction of formwork and reduction in the consumption of timber for the device should be given the most serious attention. The solution to this issue mainly consists in the multiple use (turnover) of the prepared formwork. If the design of the constructed structure does not allow the sequential movement of the finished formwork elements used in one place to another and thereby eliminates the turnover of formwork, then we should strive for timber turnover.
It follows that the formwork should be made by the collapsible from individual shields, and its design and methods, work should ensure the simplicity, ease of manufacture and assembly of formwork, as well as disassembling it with the possibly more safety of the forest.
Everything that was said in the previous chapter about the inventory of forests and scaffolds is fully applied to formwork, which should also be the inventory of construction organizations, and not be prepared for each construction site and even more so separately for each object.
The workpiece of formwork elements, as a rule, should be concentrated on the formwork courtyard and performed according to specially designed drawings, and at the facility itself, only the installation of the formwork and its disassembly should be done.
Private jumpers widely used in brick walls are laid out in brick walls by formwork. In this case, it is recommended that the device with a shield inventory formwork, which can be used many times.