What is Tunnel Formwork and how it can scale up construction industry?

Author: Dejan Jovanović| Rebar Detailer | NS Drafter

Tunnel Formwork Intro

Tunnel formwork represents a revolutionary technology in construction that enables fast, efficient, and high-quality construction of monolithic concrete structures. Using this method brings significant advantages, including reduced construction time, improved finish quality, and cost-effectiveness. This article will explore the historical development, technical characteristics, benefits, practical applications, and future of tunnel formwork, emphasizing its importance for the modern construction industry.

Historical Development and Context

Tunnel formwork was developed in the mid-20th century in response to the need for faster and more efficient construction of concrete structures. Its use particularly increased during the post-war reconstruction period when large-scale urbanization and industrialization required rapid solutions for mass construction. The development of tunnel formwork technology allowed the construction industry to meet these demands, ushering in a new era of concrete construction.

In recent decades, tunnel formwork has experienced significant advancements due to innovations in construction materials and techniques. Modern tunnel formwork systems now include sophisticated designs and materials that enable even faster and more efficient construction, making them ubiquitous in urban and infrastructure projects worldwide.

 

Technical Characteristics of Tunnel Formwork

Tunnel formwork is a system of prefabricated modules used for forming concrete walls and floors. These modules are designed for easy installation and removal, allowing for a continuous construction process. Key components of tunnel formwork include metal frames, concrete shaping surfaces, and a fastening system that ensures stability during concreting.

The construction process using tunnel formwork involves several steps:

1. Preparation and Installation of Formwork: The first step is setting up the tunnel formwork at the designated location. This includes installing reinforcement and all necessary installations, such as electrical and plumbing pipes, within the formwork. The formwork is placed precisely to ensure the accuracy of the final structure.
2. Concreting: Once the formwork is in place, concrete is poured into it. The concreting is done in a single step, forming both the walls and floors of the structure. This process allows for the creation of a monolithic structure that is extremely strong and stable.
3. Dismantling and Reuse: After the concrete has sufficiently hardened, the formwork is dismantled and moved to the next location, where the process is repeated. This cycle allows for continuous and rapid construction, especially in large-scale projects.

 

Advantages of Tunnel Formwork

Using tunnel formwork brings numerous benefits that are crucial for the modern construction industry:

1. Speed of Construction: Tunnel formwork significantly reduces construction time. Traditional methods of constructing concrete walls and floors involve multiple steps and phases, while tunnel formwork allows for simultaneous concreting, accelerating the entire process. This is particularly beneficial in large projects where time is a critical factor.
2. Quality of Finish: The concrete surfaces obtained using tunnel formwork are smooth and flat, reducing the need for additional finishing and post-processing work. This technology ensures high precision and quality of the finish, achieving an aesthetically pleasing and functional result.
3. Cost-Effectiveness: Reducing construction time and labor requirements directly impacts the overall project costs. Additionally, the reuse of formwork contributes to further cost-effectiveness, as the same modules can be used for multiple projects, lowering material costs.
4. Structural Integrity and Safety: Monolithic structures formed using tunnel formwork provide high strength and stability, increasing the safety of buildings, especially in seismically active areas. This method ensures uniform load distribution and reduces the risk of structural weaknesses.

 

Practical Application

Tunnel formwork has found widespread use in various construction projects around the world. This technology is particularly useful in residential, commercial, and infrastructure projects where speed and cost-effectiveness are crucial.

NS Drafter case Study:

One significant example of tunnel formwork application is the construction of residential complexes in urban areas. For instance, in large cities like New York, London, and Tokyo, tunnel formwork has been used for the rapid construction of high-rise residential buildings that meet high standards of quality and safety.

“Urban Residence” is a residential complex designed to meet the growing demand for quality housing in the urban center of Rotterdam. The project includes the construction of three high-rise buildings with a total of 300 residential units, commercial spaces on the ground floor, and underground parking garages. The main goal of the investors was to complete the construction as quickly as possible while maintaining high construction quality. For this project, a modern tunnel formwork system made of high-quality steel and aluminum was used.

By using tunnel formwork, the construction of each floor took about 7 days, which is significantly faster compared to traditional methods. The entire project was completed within 28 months, enabling a quicker return on investment. The concrete surfaces were extremely smooth and precise, reducing the need for additional finishing work. This resulted in saving time and money on additional work and materials.

 

Future of Tunnel Formwork

The future of tunnel formwork lies in further automation and digitization of the construction process. Innovations such as 3D concrete printing and the use of smart materials can further enhance the efficiency and sustainability of this technology. For example, using sensors to monitor the condition of concrete and advanced algorithms to optimize formwork placement can improve precision and reduce risks.

Innovations:

One possible direction for development is the use of self-healing concrete, which contains microcapsules with resin that activate in case of cracks. This technology can increase the longevity and reduce the maintenance needs of concrete structures built with tunnel formwork.

Trends:

In the future, tunnel formwork is expected to be increasingly used in smart cities and sustainable construction projects. The focus on environmentally friendly materials and construction methods will further advance the application of this technology, making it a key element of sustainable development.

Conclusion

Tunnel formwork represents a key innovation in construction, offering significant advantages in terms of speed, quality, and cost-effectiveness of building. This technology enables the creation of monolithic concrete structures that are strong, stable, and aesthetically pleasing. With the introduction of advanced technologies and materials, tunnel formwork will continue to play a crucial role in the development of modern construction projects, contributing to sustainable development and more efficient use of resources.