What are the unique advantages of steel frame structures in the reinforcement and renovation of existing buildings?

Publish Time: 2026-02-12

In the wave of urban renewal and functional upgrading of existing buildings, structural reinforcement and renovation has become an important issue in the construction industry. Faced with problems such as insufficient load-bearing capacity and limited space layout of old concrete frames, brick-concrete structures, or early steel structures, how to achieve safe, efficient, and economical performance improvement with minimal disturbance to the original system has become a key challenge in engineering design. The steel frame structure system, with its high strength, compactness, and strong assemblability, demonstrates unique advantages in the reinforcement and renovation of existing buildings. It can not only significantly improve the overall stiffness and load-bearing capacity of the structure, but also flexibly adapt to complex site conditions, achieving "minimally invasive" structural reinforcement.

1. High cross-sectional efficiency, small space occupation, and maximum preservation of usability

The renovation of existing buildings is often limited by the original building's net height, wall location, and equipment pipeline layout. Traditional reinforcement methods, such as external concrete encasing or steel plate bonding, often encroach on valuable usable space due to their large size. In contrast, box-section steel columns and beams possess extremely high moments of inertia and torsional stiffness, and their cross-sectional dimensions are far smaller than those of concrete members under the same load-bearing requirements. Especially in areas requiring additional vertical supports or transfer beams, using high-strength box-section steel columns allows for component width control within 200–300mm, almost without altering the original room layout; box-section steel beams can be concealed within ceilings or floor slab mezzanines, avoiding impact on interior ceiling height. This "small size, big energy" characteristic makes them an ideal choice for space-sensitive projects such as the protective renovation of historical buildings and the functional upgrade of hospitals and schools.

2. Factory Prefabrication, On-Site Dry Construction, Minimal Construction Disruption

Existing buildings are often still in use, and construction must balance safety, noise, dust, and schedule control. Factory building steel frame structure systems heavily rely on factory prefabrication—steel columns and beams are cut, welded, rust-removed, painted, and even fireproofed in the factory, requiring only hoisting and high-strength bolt connections or minimal welding on-site. This "dry construction" mode significantly reduces wet work, formwork erection, and curing cycles, substantially minimizing vibration impact on the original structure and disturbance to the surrounding environment. Especially in confined spaces or high-rise additions, modular steel components can be hoisted through elevator shafts, stairwells, or local openings for "precise embedding," avoiding large-scale demolition and reconstruction, truly achieving "use while modifying."

3. Controllable Structural Performance, Facilitating Collaboration with the Original Structure

Box-shaped steel components possess well-defined mechanical properties and good ductility; their stiffness and strength can be precisely controlled through cross-sectional dimensions and steel grade. In reinforcement design, engineers can use them as new lateral force resisting components, transfer layer main beams, or local underpinning supports. By rationally setting connection nodes, the new and old structures can form an effective overall load-bearing system. More importantly, steel components are lightweight, placing minimal additional load on the existing foundation, avoiding the difficulties of foundation reinforcement. Simultaneously, their excellent plastic deformation capacity helps dissipate seismic energy, acting as a "fuse" mechanism in seismic reinforcement, enhancing the overall structural toughness.

4. Facilitates Integration of Mechanical and Electrical Systems and Fireproofing, Enhancing Overall Performance

Modern renovation projects not only focus on structural safety but also need to meet requirements for fire protection, energy conservation, and intelligent systems. The internal cavities of box-girder steel beams can be pre-embedded with cable trays, air ducts, or sprinkler pipes, achieving integrated structural and mechanical/electrical design. The surface of steel columns can be directly laminated with fire-resistant boards, sprayed with intumescent fire-retardant coatings, or encased in lightweight fire-resistant partitions, balancing aesthetics and regulatory requirements. Furthermore, the recyclability of steel aligns with green building principles; even in future renovations, steel components can be disassembled and reused, reducing carbon emissions throughout their lifecycle.

In summary, the factory building steel frame structure system, with its high space efficiency, low construction disturbance, strong structural synergy, and excellent integration capabilities, constructs an "efficient, green, and human-centered" technical path for the reinforcement and renovation of existing buildings. With the development of BIM-based forward design, intelligent monitoring, and high-performance steel, this system will play an even more crucial role in urban renewal.