House Mixed Structure and Prefabricated Panel

The house mixed structure is not the same as the prefabricated panel structure; there are significant differences between the two in terms of structural form, material usage, and performance characteristics.

Structural Form and Material Differences
A mixed structure refers to a structural form composed of two or more different materials, with common combinations including the collaborative work of brick walls with concrete beams and columns. For example, in a brick-concrete structure, the brick walls bear vertical loads, while the concrete beams and columns enhance the overall integrity and lateral resistance of the structure. In contrast, a prefabricated panel structure uses factory-prefabricated concrete panels (prefabricated panels) as the main components, which are assembled on-site to form floor or roof systems. Prefabricated panels are typically unidirectional load-bearing components that rely on walls or beams for support. Their material is relatively simple, primarily concrete, possibly reinforced with a small amount of steel.

Performance Characteristics Comparison
Due to the synergistic effect of materials, mixed structures have strong overall integrity and superior seismic performance compared to prefabricated panel structures. For example, in a brick-concrete structure, the concrete beams and columns can form a frame that limits the expansion of wall cracks and improves structural ductility. In contrast, prefabricated panel structures have weak connections between components (such as relying solely on mortar or a small amount of steel lap joints), resulting in poor overall integrity. During earthquakes, they are prone to separation between panels and walls, as well as floor collapse. Most residential buildings constructed in China before 1985 adopted prefabricated panel brick-concrete structures, which performed poorly in earthquakes. For instance, a large number of prefabricated panel houses collapsed during the 2008 Wenchuan earthquake, prompting the country to gradually phase out prefabricated panels and promote cast-in-place floor slab technology. Cast-in-place floor slabs are formed by pouring concrete as a whole, creating rigid connections with beams and walls, significantly enhancing structural integrity and seismic resistance.

Application Scenarios and Evolution
Mixed structures, due to their wide material adaptability, are commonly used in multi-story residential buildings, office buildings, and other structures, especially those requiring high overall integrity. Prefabricated panel structures, due to their fast construction speed and low cost, were once widely used in low-rise residential buildings or temporary structures. However, due to their performance deficiencies, they have now been replaced by cast-in-place structures. After 2008, China's building codes explicitly required the elimination of prefabricated panels and the promotion of cast-in-place floor slabs to ensure building safety.