Nowadays, for the construction of and long structures such as silos, communication towers, shear cores of high-rise buildings, cooling towers, chimneys, ladder bases, tunnel floors, water channels, road surfaces, and similar structures that previously required heavy scaffolding around them, a method known as sliding formwork is utilized. By using the sliding formwork method, many of the surrounding scaffolding have been eliminated, resulting in increased work execution speed and an enhanced appearance for the project.
The sliding formwork system is a construction method where continuous concrete pouring takes place, and the formwork moves upward continuously. As the concrete is poured, the formwork moves vertically at a constant speed, allowing the concrete to harden before it is released from the bottom of the form. Sliding formwork is cost-effective for structures over 7 stories (30 meters) high, such as bridges and towers. It is the fastest method for constructing vertical reinforced concrete structures but can also be used for horizontal structures like walkways. As long as there is a regular shape or core, the formwork can be used to pour continuously smooth concrete without the need for joints. The formwork is self-supporting and does not rely on other parts of the building or permanent works, moving upward at a speed of about 300 millimeters per hour. The concrete used must have sufficient workability to be placed in the form and consolidated by vibration while being fast enough to escape the formwork without resistance. The setting time of the concrete must be continuously monitored to ensure that the formwork does not move upward too quickly.
A high production rate can be achieved by creating a slip, however, once continuous concreting has begun, there is little flexibility to change and therefore very careful planning is required. The use of cranes is minimized Assembly of formwork and scaffolding is minimized and has higher safety. Less manpower is required compared to similar cases in a phased manner (ascending or leaping). There are flexible conditions where conical structures can be obtained by reducing the wall thickness (gradually, in a short distance or in steps). It should be noted that the main cost of making a sliding formwork is to hold the concrete until it can safely transfer its concrete and other imposed loads without tearing off.