Prefabricated Panel Assembly Houses

Prefabricated panel assembly houses are mainly divided into two categories: traditional prefabricated panel houses and modern prefabricated assembled buildings. There are significant differences between the two in terms of structure, performance, and application scenarios.

Traditional Prefabricated Panel Houses

Traditional prefabricated panel houses use prefabricated panels as their core components. These panels are factory-made cement components formed by nailing wooden models, laying out steel bars, and pouring cement. They come in two types: solid and hollow. The hollow structure achieves lightweighting by reducing the non-load-bearing concrete. This building form originated in the early 20th century and was initially used mainly for floor slabs and roof insulation layers. Most residential buildings constructed in China before 1985 adopted this structure. Existing traditional prefabricated panel houses generally have the following issues:

• Weak earthquake resistance: Due to poor structural integrity, they are difficult to withstand horizontal seismic forces and are prone to component detachment or overall collapse during earthquakes.
• Poor sound and thermal insulation: There are many connection gaps between the prefabricated panels, allowing efficient air conduction of sound waves and heat, resulting in high indoor noise levels and significant temperature fluctuations.
• Limited service life: Concrete is prone to aging due to carbonation, steel bar corrosion, and other issues. The design life is about 30-50 years, and some early buildings are approaching their service limits.
• Limited renovation: Since 2022, China has implemented renovation policies, focusing on repairing and renovating prefabricated panel houses and only demolishing buildings that meet the criteria for dangerous houses. The renovation space is significantly restricted by the structure.

Modern Prefabricated Assembled Buildings

Modern prefabricated assembled buildings are constructed by industrially producing building components and assembling them on-site. The technology covers prefabricated concrete structures and steel structures, with components including prefabricated beams, slabs, walls, columns, and other products. They offer advantages such as shortened construction periods and reduced pollution. The main types include:

• Panel assembled buildings: Using prefabricated wall panels and floor slabs as core components, they can expand usable area but have limited design flexibility due to the standardization of prefabricated components.
• Box assembled buildings: Formed by combining prefabricated functional units (such as bathroom and kitchen modules), they increase construction speed by 50%-70% but have high requirements for transportation and lifting equipment.
• Modular buildings: With the highest level of integration, buildings are disassembled into independent modules (including ceilings, floors, water and electricity pipelines, etc.), manufactured in factories, and then assembled on-site. For example, in a public housing project in Shenzhen, Guangdong, five residential buildings nearly 100 meters high were assembled from 6,028 concrete modules. The completion and delivery time was reduced from 2.5-3 years to 1 year, on-site labor was reduced by about 50%, and noise and dust pollution were significantly reduced.

Modern prefabricated assembled buildings achieve goals such as shortening construction periods by more than 60%, ensuring quality control, and promoting energy conservation and environmental protection through standardized design, factory production, and assembly construction. They are the mainstream direction of current building industrialization development.