In order to maintain the assumed spacing between the formwork panels, we utilise formwork ties together with their accessory equipment. A formwork tie is a threaded rod or wire, the task of which is to transfer the expansion force emerging as a result of pressure of the concrete on the formwork panels. A spacer covering the tie to protect it against contamination by the concrete mix also prevents the formwork elements from moving with respect to each other. A spacer is a type of plastic or concrete pipe, the use of which, beside protecting the formwork elements against shifting, also allows the tie to be recovered and utilised again.
Wire formwork tie in a protective plastic or concrete pipe
The simplest formwork tie, which one can produce at the construction site, is a tie manufactured out of wire having a thickness between 5 and 10 mm. The tie is placed in a spacer pipe, always ending (in case of a plastic spacer) with plastic cones or a special gasket in case of a concrete spacer. Wire protective in this way is tensioned with a special wire grip and tie wire tensioner. Openings required for process reasons left over after removal of the formwork are covered with caps and in case of concrete piping, are sealed up with special filler mortar.
|Closure of process openings with STOPF caps: plastic pipe and IN cap.||Closure of process openings with FLUPP caps and EX22 concrete cap glued using A+B two-component adhesive: plastic pipe and EX22 cone.|
|Close of process openings by FLUPP caps or FLUPP ST caps and EX22 plastic caps or STERN caps and EX22/50 concrete caps glued using A+B two-component adhesive: plastic pipe and EX22/50 cone.||Closure of process openings by FLUPP caps and EX WU concrete caps glued using A+B two-component adhesive: plastic pipe and EX WU cone.|
|Closure of process openings by PCW caps and FB caps glued with A+B two-component adhesive and sealing mortar: plastic pipe and FB pipe end seal.||Closure of process openings by EX 22 plastic caps and filler mortar: plastic pipe and EX22 cone.|
Threaded wire tie in protective plastic pipe
Betomax and SGS threaded formwork ties for formwork components with spacers and nuts transfer loads in the range from 85 kN to 240 kN. Two types are available. The first type are cold-rolled Betomax B formwork ties, which, thanks to their low carbon content, exhibit good welding properties. They can be bend (i. e. to make wobble anchors, anchor loops and hook anchors). The second type of ties, bearing the name Uni, do not have this property; their advantage is a double symmetric spacing within the thread along the ties, facilitating its self-cleaning properties when applying and removing the nut.The length of the formwork tie is appropriately selected to fit the width of the formed wall and the formwork system.For economic reasons, the best solution is the placement of a formwork tie in a protective spacer pipe. In case of a plastic pipe ending with plastic cones, which themselves are removed when the concrete component formwork is dismantled, the openings created this way are sealed by concrete plugs using the A+B adhesive. The passage of the tie is sealed against the water load with a water partition, which provides a seal warranty against a water column of up to 20 metres under pressure.
|STOPF plug for plastic pipe ending with the IN end.||Ex22 plug for plastic pipe ending with the EX22 cone using the A+B double component adhesive.|
|EX22/50 plug for plastic pipe ending with the EX22/50 cone using the A+B double component adhesive.||EX-WU plug for plastic pipe ending with the EX-WU cone using the A+B double component adhesive.|
Method of protection of a tie passage against water load using a water partition, which provides a seal warranty against a water column of up to 20 metres under pressure.
Threaded bar tie in protective concrete pipe
Tightness of a tie passage can also be guaranteed using a spacer concrete pipe, the interior of which, after removal of the formwork, is covered by an appropriate number of concrete plugs with a diameter of 22 mm and a length dependent on the water pressure. Before commencing with the application of the plugs, it is recommended to place a PCW plug in a FB pipe, which will reduce the consumption of the adhesive. The entire passage is levelled with levelling mortar.
|Plugging a concrete pipe, ending with a FB pipe end seal, with a FB plug using A+B two-component adhesive and filling mortar. It is a method guaranteeing seal tightness for a water column of up to 20 metres.|