Transforming toward industrialization, digitalization, and green development is a practical necessity for the high-quality development of the construction industry and a major trend for the industry's future. Steel structure buildings inherently possess the characteristics of prefabrication, industrialization, and green development. Fully leveraging their advantages of being "light, fast, good, and economical," and driving high-quality development of prefabricated steel structure buildings through dual-wheel innovation in technology and management, is an important focal point for developing new quality productive forces.

Grasp the Transformation Trend of the Construction Industry and Recognize the Advantages of Prefabricated Steel Structure Buildings

China's construction industry remains a labor-intensive traditional industry with relatively extensive construction methods, and there is still a certain gap compared with the requirements for high-quality development. The National Housing and Urban-Rural Development Work Conference held at the end of last year emphasized deepening the supply-side structural reform of the construction industry, continuously working hard on the transformation toward industrialization, digitalization, and green development, striving to provide high-quality building products to the whole society, and building an upgraded version of "Built in China." This has clarified the direction and path for the high-quality development of the construction industry.

The connotation of industrialized construction is factory fabrication and on-site installation, introducing the manufacturing industry's concepts of standardization, componentization, and prefabrication into the construction industry, and turning buildings into industrialized products. However, it is not easy for the construction industry to achieve "building houses like making cars." From practice, building industrialization is even harder than making cars. The reasons are: first, building materials cannot be turned, planed, milled, and shaped like car parts. Second, building components are not only large, bulky, and heavy, but also require completely different installation equipment and methods; buildings are ultimately installed on site rather than in a factory. Third, building products have obvious individualized characteristics—no two houses are exactly the same. The characteristics of industrialized construction are standardized design, factory production, prefabricated construction, integrated decoration, information-based management, and intelligent application, with the core being prefabricated construction. Therefore, for buildings to achieve "building houses like making cars," prefabricated buildings must be vigorously developed, which is an important lever for achieving industrialization.

The core technologies of digitalization include BIM (Building Information Modeling) and digital twins. The digital transformation of the construction industry requires digitizing all industry standards, rules, experience, and requirements to form massive data, and running through the entire building life cycle and the entire industrial chain through information platforms. New-type industrialization is the integration of digitalization on the basis of industrialization, promoting changes in management models and giving rise to new construction methods. Intelligent construction is likewise based on digitalization. The coordinated development of intelligent construction and new-type building industrialization aims, based on the actual state of industry development, to strive toward a higher level of intelligence while consolidating industrialized development. The focus of intelligent construction is the integration of artificial intelligence technology with engineering construction technology, with the core technologies being intelligent algorithms and the application of intelligent construction robots. At present, most automated equipment in the industry cannot yet be called "intelligent." Intelligence emphasizes "machines replacing humans," enabling human-machine interaction and, through autonomous learning, achieving cognitive upgrading. The coordinated development of intelligent construction and new-type building industrialization conforms to the current state of China's construction industry development, is innovative and advanced, can bring fundamental changes to the industry, and is the key to the development of new quality productive forces.

The construction industry's transformation toward industrialization, digitalization, and green development: industrialization and digitalization are the means and methods, while green development is the goal. The ultimate goal of the transformation is to change the traditional extensive construction methods and development models, achieve quality improvement, cost reduction, and efficiency enhancement, create green products, and build "good houses." Good houses must be safe, practical, aesthetically pleasing, and green, achieving the "four savings and one environmental protection." The concept of green development must run through the entire life cycle of engineering construction, including the selection of green building materials and material recycling, the implementation of green design, construction, and operation and maintenance management, as well as the application of modern advanced technologies such as new energy utilization, rainwater and snow collection, resource-based treatment of construction waste, and carbon emission reduction.

Steel structure buildings have typical characteristics of prefabrication, industrialization, and green development, with advantages of being light, fast, good, and economical. Light means steel structure materials are lightweight and high-strength, with small component cross-sections, light self-weight, and high load-bearing capacity, suitable for larger spans and convenient for transportation and installation. Fast means steel structures are fabricated in factories and can be produced in batches as large components, with a high degree of industrialization; adopting the construction method of factory manufacturing and on-site high-strength bolt installation can effectively shorten the construction period, creating conditions for reducing costs and giving play to the economic benefits of investment. Good means the raw materials have good mechanical properties and high reliability, good weldability, sealing performance, and durability, good structural seismic performance, are easy to disassemble, and have good adaptability to new technologies. Economical means that compared with concrete structures, the comprehensive cost over the entire life cycle is lower, and steel can be recycled. Developing prefabricated steel structure buildings is not only a requirement for the construction industry's transformation toward industrialization, digitalization, and green development, but also an inevitable trend in the course of building development and an important support for building good houses.

Clear Obstacles to High-Quality Development and Promote the Accumulation and Momentum of Prefabricated Steel Structure Buildings

To fully leverage the advantages of steel structures, we must face up to the problems encountered in development, take targeted measures, clear obstacles for high-quality development, and achieve the leap from steel structures in prefabricated buildings to prefabricated steel structure buildings.

Establish the concept of "full prefabrication." Not only must the structure be prefabricated, but the external enclosure structure, interior systems, equipment and pipelines, and decoration must all be prefabricated. To achieve full prefabrication, information connectivity based on BIM technology is a problem that must be solved first.

Establish the concept of "integration." First, integrate design, fabrication, construction, operation, and maintenance to deeply advance cost reduction and efficiency enhancement. The weak point of steel structure development is the relatively high cost of the construction phase, but if considered from the perspective of integration from design to operation and maintenance, costs can be significantly reduced. Second, buildings, structures, components and parts, mechanical and electrical equipment, and decoration must be integrated. For example, high-rise steel structure buildings have greater flexibility and high requirements for the coordinated deformation capacity of the enclosure system and the structure; otherwise, the enclosure system is prone to deformation and cracking, affecting the building's usability and lifespan. Incorporating structural components and parts such as insulation, heat preservation, anti-corrosion, fire protection, daylighting, and shading into integrated consideration can not only well solve a series of problems but also improve building quality. Third, the application of new technologies such as green and low-carbon technologies must be integrated with building functionality. Fourth, the formulation of integrated technology integration standards must be put on the agenda.

Optimize the structural system. Centering on the development goals of prefabrication and industrialization, optimize the structural system of steel structure buildings, and truly work hard and achieve practical results in reducing components, improving connection methods, and promoting standardized development.

Optimize design. Through optimized design, solve the problem of exposed beams and columns in steel structure buildings. In practice, simply replacing reinforced concrete components with steel components makes it difficult to leverage the advantages of steel structures, reduces usability, and increases steel consumption. Through design innovation, better leverage the advantages of steel structures in large spaces and flexible floor layouts.

Research and develop construction methods adapted to industrialization. Standardized design, factory-produced components, and prefabrication of structures, mechanical and electrical systems, and decoration are the distinctive advantages of steel structure buildings. We must fully leverage these advantages, accelerate the development of modular buildings, achieve rapid construction, reduce on-site welding operations, save labor, and reduce environmental pollution.

Research and apply supporting components and parts. First, because buildings have individualized characteristics, components and parts are difficult to mass-produce, and the degree of standardization and generalization is relatively low; second, the industrial chain is not yet complete; third, the "three boards" system (floor slabs, interior wall panels, and exterior wall panels) has poor compatibility with building structures. The general system is based on the standardization and universality of components and connection technologies, is suitable for specialized and socialized production, and is a relatively perfect form of industrialization. Only by vigorously developing a general system based on general components and parts can we lay the foundation for "building houses like making cars."

Change the understanding of hollow floor slabs. Prefabricated buildings use composite floor slabs, with secondary pouring at connection locations, which is not a perfect industrialized construction method. Industry enterprises should center on the core of industrialized construction, balance individualized and standardized needs, re-recognize the value of hollow floor slabs, research and develop new processes, overcome their drawbacks, leverage their advantages, and strengthen the weak link of prefabricated buildings in floor slabs.

Solve issues of public concern. First, the cost issue. The cost of steel structure buildings is slightly higher than that of concrete structure buildings. We must calculate the accounts well for the public from the perspective of comprehensive life-cycle cost and win market recognition. More importantly, we must continuously reduce the cost of prefabricated steel structure buildings and improve cost-effectiveness through technological and management innovation. Second, the issue of poor corrosion resistance of steel structures. Steel structures are prone to rust in humid and corrosive media environments, but under normal use environments and normal maintenance conditions, their durability exceeds that of concrete structures. The application of weathering steel and new anti-corrosion technologies can further improve the durability of steel structures. However, anti-corrosion of enclosure structures and connections must be highly valued, with regular maintenance. Third, the fire protection issue. Steel structures are heat-resistant but not fire-resistant, so fire protection measures must be well implemented, combining active and passive fire protection. Fourth, the comfort issue. Through reasonable design, careful construction, and careful maintenance, ensuring structural stiffness, preventing wall cracking and leakage, and ensuring insulation, heat preservation, sound insulation, moisture proofing, airtightness, and protection requirements, ideal comfort can absolutely be achieved. With the application of new technologies, the comfort of steel structures can be further improved.

Accelerate research and development of key technologies. "Bottleneck" problems such as key software, laser 3D scanners, construction robots, and 3D printing equipment have not yet been well solved. BIM technology urgently needs a fundamental breakthrough. The development of intelligent construction technology is still in the exploratory stage, and the coordinated development of intelligent construction and industrialization still has a long way to go.

Improve the quality of practitioners. Steel structure buildings are technologically intensive and place high demands on practitioners' capabilities. On the one hand, enterprises should, through training and learning, change practitioners' traditional mindset of concrete building construction, improve their understanding of steel structure innovation and development, and continuously enhance technical capabilities and management levels; on the other hand, universities should respond to market demand, reform talent training models, optimize specialty settings, promote interdisciplinary integration, and vigorously cultivate compound talents.

At present, China's steel structure buildings are developing rapidly, with large numbers of steel structure venues, airports, stations, and high-rise buildings rising rapidly. As the construction industry's transformation toward industrialization, digitalization, and green development continues to deepen, prefabricated steel structure buildings will accumulate momentum and take shape, stimulating the formation of new development momentum and new advantages characterized by innovation and with quality as the key, and gathering momentum and empowering the development of new quality productive forces.