Building Architecture: Cast-in-Place and Prefabricated
Reinforced concrete floor slabs can be classified into cast-in-place monolithic, prefabricated assembled, and assembled monolithic types based on construction methods, with the following characteristics for each:
Cast-in-place monolithic floor slabs: Formed by pouring concrete on-site, they integrate with the main building structure. Their core advantages lie in strong integrity and excellent seismic performance. During earthquakes, the floor slabs deform in coordination with the walls, making structural separation less likely. Additionally, they are highly adaptable, allowing flexible adjustments in slab thickness and shape to accommodate complex spatial requirements. For example, cast-in-place floor slabs in bathrooms can completely eliminate water leakage issues due to the absence of joints. However, significant drawbacks include a long construction period, involving multiple processes such as formwork erection, steel bar tying, pouring, and curing, as well as a large amount of formwork used, leading to higher material and labor costs.
Prefabricated assembled floor slabs: Produced in a factory to standardized specifications and then transported to the site for assembly. Their outstanding feature is fast construction speed, as only hoisting and positioning are required to complete the main structure construction, and low formwork consumption, significantly reducing material costs. Nevertheless, this type of floor slab has obvious defects: poor integrity, with connections between slabs relying on joints, making them prone to structural damage due to joint failure during earthquakes; low flexibility, requiring pre-determination of slab type specifications, making it difficult to adapt to on-site changes; and weak waterproof performance, with joints easily becoming leakage pathways, thus strictly prohibited for use in wet areas such as kitchens and bathrooms. Despite these drawbacks, their low cost and rapid construction characteristics still make them suitable for temporary buildings or projects with tight budgets.
Assembled monolithic floor slabs: Combine the advantages of the previous two types, adopting a composite structure of a prefabricated base slab and a cast-in-place layer. The prefabricated part enhances construction efficiency, while the cast-in-place layer strengthens integrity, achieving a balance between structural performance and construction speed. However, this method has high technical requirements: complex joint treatment, necessitating processes such as steel bar connection and concrete pouring to ensure coordinated work between the prefabricated and cast-in-place parts; and high cost, as it involves the production, transportation of prefabricated components, and secondary construction on-site, with a comprehensive cost usually higher than that of pure cast-in-place or pure prefabricated solutions. Its application scenarios are mostly medium- to high-rise buildings with high requirements for both structural performance and construction efficiency.
