Discover the climbing formwork systems: Types, applications and the best option according to the site
The construction industry is constantly evolving, and every day, new techniques and systems are developed to facilitate the work of professionals. In this article, we will delve into the world of climbing formwork and explore the different types of systems available, their applications depending on the type of construction site and which options are the most suitable depending on the needs of each project.
What is climbing formwork?
Climbing formwork is a system used in the construction of vertical concrete structures, such as piles, walls and high-rise buildings. It consists of a set of temporary molds that support the fresh concrete until it reaches the required strength to support its own weight. As the concrete hardens, the climbing formwork system moves upwards, enabling the construction of new sections of the structure.
Benefits of climbing formwork
The use of climbing formwork systems offers many advantages over traditional construction methods:
- Increased speed of execution: By enabling the construction of new sections of structure without having to wait for the concrete to harden completely, climbing formwork speeds up the construction process.
In addition to not having the need to make any additional assembly when increasing in height.
- Better quality of the concrete: By keeping the fresh concrete in a controlled mold, climbing formwork ensures better concrete quality and uniformity.
- Less labor: Climbing formwork requires less labor compared to other methods, reducing labor costs.
- Greater safety: By keeping the formwork in position while the concrete hardens, climbing formwork provides a safer working environment for workers.
What types of climbing formwork systems are there?
There are several types of climbing formwork systems, which adapt to different needs and site features. Some of the most common are:
- Climbing formwork in sections
- Climbing formwork with carriage
- Interior climbing formwork
- Single face climbing formwork
- Low Load Capacity (5tn) Self-climbing formwork
- High Load Capacity (10Tn) Self-climbing formwork
Climbing formwork in sections
This system is used in the construction of walls and columns of medium height. The formwork and its support (climbing bracket) are moved independently using a crane (first the bracket is placed and then the formwork is placed on it), enabling gradual progress of the work. This type of formwork is especially useful when the structure presents changes in section or geometry along its height, since it enables quick and easy adjustment of the formwork.
Climbing formwork with carriage
In this case, the formwork and its support or console are moved together using a crane, which facilitates its assembly and disassembly in large-scale works. This system is especially suitable for high-rise buildings, where it makes the most sense.
This system is particularly suitable for repetitive structures in which the section will not change in height and in which we have sufficient auxiliary means when lifting them.
Interior climbing formwork
This type of climbing formwork makes enables covering the internal spaces of stair/elevator shafts, allowing this platform to be raised using a crane. The system rests on 4 negatives obtained with recoverable boxes left in the previous set-up.
In case of wall thicknesses that do not allow the use of the box, a support head with recoverable anchorage can be used.
Single face climbing formwork
The single face climbing formwork system makes it possible to form walls or piles at height, without the need for dywidag bars. This system can also be used to solve inclined walls or piles, anchored directly to the concrete of the previous placement.
It is especially recommended for the execution of dams.
Low Load Capacity (5tn) Self-climbing formwork
This system is used in the construction of high walls and piles. The formwork is moved by means of rails fixed to the structure, which guarantees greater precision and safety during the process. The modules can be handled by crane or with hydraulic devices (self-climbing).
Independent modules are normally used. The hydraulic equipment for the changeover is simple and is shared between the different modules.
The great advantage lies in the fact that it enables the vertical displacement of the formwork with winds higher than the maximum winds with which a crane can be used.
High Load Capacity (10Tn) Self-climbing formwork
The self-climbing formwork system is guided in displacement through hydraulic cylinders. It is used for very high buildings or piles (from 20 floors approximately), where the productivity factor is very important, and the use of a crane is complicated and costly.
In this case, lifting can be done by jacks (5 ton hydraulic cylinders), or by moving the entire structure at once by means of specific hydraulic equipment with high load capacity and precision (10 ton hydraulic cylinders).
In climbing formwork systems, it is very important to be careful with the anchorage, which is the element that supports the weight of the system, and also all the pressure of the concrete in the case of a single face climbing system.
What are the most common types of anchors used in climbing formwork systems?
- M24 bar: this is the most commonly used type in case of the possibility of a through bar in the wall. The climbing faces can be two or only one, and in this case, the bar is only designed to support the weight of the climbing system, but not the pressure of the concrete.
- M24 cast-in tie: The cast-in tie has the same function as the through bar, but enables the two climbing faces to be positioned independently, without them being aligned. Also in this case, the tie is only designed to support the weight of the climbing system, but not the pressure of the concrete.
- 5 Cast-in anchorage: The DW26.5 cast-in anchorage is used in case of a single face climbing systems, where the anchor has to withstand both the weight of the system and the pressure of the concrete. For this reason, it is necessary to calculate very well its resistance according to the concreting height, which cannot in general be higher than 3m.
- Helical anchorage: This type of anchorage has the same function as the DW26.5 cast-in anchorage, but enables the total recovery of the anchor after setting, providing a great advantage in economic terms when many lifting operations are foreseen.
How to choose the right climbing formwork system according to the work
When choosing a climbing formwork system, it is important to consider the following factors:
Height of the structure: The height of the structure will determine which type of climbing formwork is most suitable. For very high structures, guided or self-climbing systems are usually the best option, while for medium heights, climbing formwork in sections may be more appropriate.
Geometry and cross-section of the structure: Variations in the geometry and cross-section of the structure may require adjustments to the climbing formwork. In these cases, self-supporting systems or in sections can be more versatile and easier to adapt. If the geometry foresees situations with inclined walls, the single face climbing system may be the optimal solution to adapt.
Environmental conditions: The most important conditions to take into account are wind ones. The higher you go up in height, the more you have to take into account wind speed and its pressure on the formwork.
Cost and efficiency: While the initial investment in climbing formwork systems may be higher than other construction methods, it is important to consider the potential savings in terms of execution time, concrete quality and labor reduction. A project-wide cost analysis can help determine which climbing formwork system is the most cost-effective and efficient for each work.
Safety and ergonomics: Worker safety is a key factor to consider when selecting a climbing formwork system. Guided and self-supporting systems generally provide a safer working environment, as they reduce the need for working at height and ensure greater stability of the structure. In addition, it is essential to consider the ergonomics and ease of use of the system to minimize the risk of injury and increase worker productivity.
Climbing formwork is a key tool in the construction of vertical concrete structures, and its correct choice and application can make the difference in the success of a project. It is essential for construction professionals to be familiar with the different types of climbing formwork systems, their applications depending on the type of work and how to determine the best option according to the needs of the project.
The most suitable climbing formwork system can be selected for each project by evaluating key factors such as structure height, geometry and section, environmental conditions, productivity and safety, optimizing the efficiency and quality of the construction process.
In conclusion, climbing formwork is an efficient and innovative solution that facilitates the construction of vertical concrete structures, reducing execution time, improving concrete quality and increasing workplace safety. By understanding the characteristics and applications of different climbing formwork systems, construction professionals can make informed decisions and ensure the success of their projects.