Innovative Concrete Structures: Cubiax
Cubiax is a lightweight ceiling system designed around hollow spaces within concrete. By using the Cubiax system, less concrete is required, making it both cost-effective and reducing the overall weight of the structure. Cubiax ceilings can be constructed using either flat or spherical voids. These voids are typically made from recycled polyethylene or polypropylene, making them environmentally friendly.
Research into lightweighting and eliminating inefficient concrete began in 1985 at German universities and the Cubiax company, with the collaboration of engineers from Switzerland and other European Union countries.
Cubiax ceiling technology is based on the construction of two-way reinforced concrete slabs where the removal of non-structural dead load maintains the two-way spanning capacity. Cubiax is one of the most modern methods of reducing structural weight while maintaining structural performance. It has received technical approval from the German Institute and certification from the Building and Housing Research Center of the Ministry of Roads and Urban Development. It has also won the German Resource Efficiency Award and was selected as the top green technology of 2010 in Switzerland.
The purpose of these voids and spherical or flat elements is to eliminate unnecessary concrete. The Cubiax slab system works by forming a strong concrete membrane at the top and bottom of the slab, along with an internal grid of beams (created by placing hollow spheres throughout the mid-span of the concrete slab in two perpendicular directions). This eliminates non-structural dead load and enhances two-way spanning capacity, allowing for higher load-bearing capacity. The basic principle of the Cubiax system is to create a flat slab through in-situ concreting with permanent voids in two directions.
Types of Cubiax Ceilings
Cubiax ceilings can be constructed using either flat or spherical voids. Flat voids are used in slabs with a smaller thickness and have a height of 10 to 22 centimeters. Spherical voids are used in thicker slabs and have a height of 25 to 45 centimeters. These voids are suitable for use in wide concrete spans. The Cubiax system can be prefabricated, semi-prefabricated, or constructed in-situ. It can also be easily combined with other construction methods.
Disadvantages of Cubiax
The Cubiax system is not suitable for small projects as it is not economically viable.
This system originated in European countries that are not seismically active, whereas Iran is located on an earthquake belt. Therefore, there is limited data on the seismic performance of this system, and further testing is required.
Advantages of Cubiax
- Reduced concrete consumption
- Reduced construction time
- Reduced reinforcement consumption
- Reduced overall height due to optimized ceiling height
- Reduced installation costs for building services (elimination of beams and associated problems) and reduced structural elements. These are the economic advantages of Cubiax, in addition to other benefits discussed below.
From a construction and structural lightweighting perspective, Cubiax offers numerous advantages, including:
- Increased usable space and the ability to span up to 18 meters without columns
- Reduced concrete consumption
- The ability to create openings of any shape and size in the ceiling
- Ease of horizontal and vertical conversion
- Suitability for various uses and flexibility in architectural planning (reduced number of columns)
- The ability to create cantilevers up to 7 meters.
Cubiax Design
The thickness of the Cubiax slab depends on various factors such as span, number of stories, material consumption, and the final weight of the structure. Therefore, a specific thickness cannot be determined for all slabs. For example, for a span of 14 to 16 meters, a thickness of approximately 45 to 60 centimeters is used. In this technology, dead load is eliminated, and two-way spanning capacity is maintained.
Cubiax slabs can reduce the weight of a one-square-meter slab by up to 30% compared to a flat slab of the same thickness. As a result, the flexural capacity of this type of slab is significantly increased compared to a flat slab of the same weight.
Conclusion
In this article, we have attempted to introduce you to one of the innovative construction methods and novel concrete structures: Cubiax. We hope you find this information useful.
