Formwork is one of the key elements in construction. It is made of different materials, mainly metal or wood. Framework is built to give stable shape to different kinds of construction mixes and mortar. It also provides true geometrical sizes and position in space. Accurate formwork can be built only provided high-quality fittings, which would support the construction.
The main fitting elements are:
- Clamp locks;
- Tie rod;
- Tie screw;
In formwork construction, locks provide stability – they connect the panels of the form. That is why, they are usually made of special alloy steel or iron. Locks can be used for panels from all kinds of materials because they meet all the required demands of strength stability.
There are four types of formwork locks:
- Key locks can be applied both vertically and horizontally; and can additionally be used for aligning panels and boards. This type of fittings provides tight joints: this is why the concrete surface comes out perfectly even. Such locks are non-assembled because they are produced by precision molding, which increases stability and strength.
- Spring-loaded lock. Its main advantage is versatility: it can be applied for any kind of formwork. The lock is put onto the construction and fixated with a key. In this case, the advantages are quick and simple fixation and reasonable price.
- Universal (long) locks. Application area: connection of panels and alignment of joint areas. Such locks allow to make right-angle joints, which is especially important for foundation. The main advantages: easy to install, indispensable for joint, outer and inner angles, joining strength.
- Screw-type locks. Are the most popular ones in construction. Allows to make inserts between the panels, and is light-weight. The construction elements are connected with the rod and screw welded on the lock. This lock type allows to implement all kinds of projects from different materials.
Tie Screw Rod System
Due to the fact that these fittings are mainly used in solid constructions, each element must first undergo a rupture test. Tie rod is intended for fixation and fastening of formwork panels. It is also supposed to ensure effective and stable resistance of the construction to the load of the concrete.
The screw comes with the tie rod. It is characterized by extended contact area with the panel edge and has a special surface for applying the pressure. The screw is made by precision molding, which ensures its exceptional strength; the carving is made either upon production, or later.
The tie screw rod system has a number of advantages:
- Undergone tear and strength testing, complies with DIN 18216;
- Resists great load;
- High welding capacity;
- Eliminates random shifts thanks to extended carving.
Plastic bar supports
Accurate fixation of the metal carcass of the formwork eliminates corrosion. It helps to preserve the initial strength properties of the iron concrete. That is why, it is important to choose plastic (polymer) supports, since they minimize the risks of corrosion and effectively function throughout many years.
There are the following types of supports:
- Wall supports. They are meant to build a protective layer between the carcass and the formwork. Used in vertical constructions.
- Flooring supports. Used in horizontal surfaces, also forming a protection layer.
- For loose ground. These supports are used not only on loose ground, but also when installing thermal and water insulation. They preserve the protective layer, sinking into ground, and also in cases when the supports are pressed into the thermal and water insulation materials.
Selection of formwork parts directly depends on the materials to be used. It is also important to take into consideration the future structure and the load on it. Other important indicators for implementing a project are ground, climate and flooding possibility: this directly affects the stability of the building. Only a complex analysis of all the elements of the future project allows selection of correct materials and a successful implementation of the project.