The three types of slip formwork: Vertical, conical, and horizontal slip formwork
Slipforming is most commonly associated with the construction of vertical, concrete buildings, also sometimes referred to as “traditional slipforming”. However, slip formwork is not limited to vertical structures. Both conical and horizontal slip formwork are also possible. In this article we’ll give a brief overview of these sub-types of slipforming, what types of structures they are used to build and how they work.
1. Vertical slip form construction
Vertical slipforming consists of pouring concrete around cross-sections which mostly have the same diameter maintained throughout the height of the structure. The slipform formwork is gradually lifted with the help of working platforms and using hydraulic jacks in order to raise the levels of the structure. It is mainly used to build high-rise structures such as skyscrapers and towers.
2. Conical slip form construction
Conical slipforming is a more developed method than the traditional construction method, where the main difference in the technique is the change in the length of the cross-section diameter. This change in the cross section is what eventually results in the conical shape of the structure. Conical slipforming was originally developed to construct concrete structures with continuously changing dimensions like wall thickness.
The thickness of the wall constructed depends on multiple factors along with the cross sections such as the size of the cone, the material used in construction and of course, the height of the structure. The conical slip form construction method was previously mostly used to construct conical towers and industrial chimneys, but is nowadays use for different commercial projects.
3. Horizontal slip form construction
Horizontal slip form construction is a method used for constructing continuous concrete elements, such as kerbs, drainage channels, tunnels, safety barriers, and a lot more. It involves the extrusion of concrete in situ rather than casting it in short lengths. The principles for horizontal slip formwork construction are the same as vertical slipforming.
Horizontal slip formwork involves concrete being poured into a continuously moving plant. It is then vibrated and extruded from a specially designed formwork mould to produce the required structure profile.