In the field of structural restoration, the need for efficient, cost-effective, and durable flooring systems is becoming increasingly important, especially when reviving old buildings. A novel cold-formed steel system has been proposed for this purpose. Developed by Ahmed Shamel Fahmy, Sherine Mostafa Swelem, Rowida Saad Farrag, and Wael F. M. Mobarak, this system introduces a built-up CFS flooring design that combines lightweight steel components with cast-in-situ concrete for a robust and flexible solution. The system aims to address the unique challenges of restoring old buildings with minimal disruption, reduced costs, and improved structural performance.
This innovative CFS system is structured as a box section, incorporating several key components: steel decking, sigma sections, stiffening angles, and a concrete slab. These components are assembled in the factory and transported to the construction site, significantly reducing on-site construction time. The system has been specifically designed to make the restoration of old buildings easier, particularly when dealing with floors originally constructed from timber, which over time has deteriorated. The system's design enables rapid assembly without the need for heavy machinery or extensive labor, making it ideal for urban environments with limited space and mobility.
The primary objective of this CFS system is to create a high-strength, lightweight flooring solution that minimizes both the time and cost of restoration. The system utilizes steel decking in a longitudinal direction, which simplifies installation and reduces the need for overlapping panels. This approach leads to a 20% reduction in the cost of steel decking compared to traditional methods, as well as a significant reduction in the number of screws required for assembly. This innovation is not only cost-effective but also environmentally friendly, as it reduces the number of materials and the energy required for installation.
A key aspect of this flooring system is its ability to increase the structural capacity of old buildings without requiring extensive modifications to the existing framework. The CFS sections are designed to be flexible in terms of load-bearing and can easily adapt to irregular geometries. Furthermore, the system enhances the durability of the structure, providing a long-lasting solution that improves the quality of life for building occupants. This is particularly beneficial for historical buildings that need to maintain their aesthetic and structural integrity while meeting modern standards for safety and comfort.
The system was tested experimentally through a series of loading tests on four specimens, which demonstrated its superior stiffness and flexural strength. The tests revealed that the CFS flooring system could withstand significant loads without experiencing local buckling or distortion, except at the end supports where failure occurred due to distortion. This finding highlights the strength and resilience of the system, which can reach its ultimate strength while maintaining stability under load. The load-deflection relationship, longitudinal strain distribution, and failure modes were also analyzed, showing that the system behaves as expected under realistic conditions.
Additionally, the system’s performance was further evaluated through a numerical study using a three-dimensional finite element model. The theoretical results closely matched the experimental data, confirming the accuracy and reliability of the proposed design. This agreement between theoretical and experimental results underscores the system’s potential for practical application in building restoration projects. It also validates the use of cold-formed steel in the construction of lightweight, high-performance flooring systems that do not compromise on strength or safety.
In terms of installation, the CFS flooring system is designed to be user-friendly and easy to assemble. The components are prefabricated in the factory, which reduces the need for on-site work and minimizes the use of heavy construction equipment. This is particularly important in urban areas where space is limited, and cranes or other large equipment may not be feasible. The use of self-drilling screws for connecting the various components further simplifies the process, as these screws eliminate the need for prefabrication or specialized tools. This system is not only faster and more efficient than traditional restoration methods but also more sustainable, as it minimizes waste and reduces the environmental impact of construction.
The proposed system also addresses the challenges faced by older buildings with structural integrity but damaged floors. The new flooring system can be easily integrated into the existing structure, providing a seamless and cost-effective solution for building owners looking to restore and extend the life of their properties. By using CFS sections, the system can be tailored to meet the specific needs of each building, ensuring that the flooring is both functional and aesthetically pleasing.
In conclusion, the proposed cold-formed steel flooring system presents a groundbreaking solution for the restoration of old buildings. It combines the advantages of lightweight steel, ease of installation, and enhanced structural performance, making it a highly effective and cost-efficient option for building restoration projects. This system has the potential to revolutionize the way old buildings are renovated, offering a sustainable, durable, and fast solution that meets the demands of modern construction while preserving the heritage of the past.
