Old Prefabricated Concrete House Structure

The old prefabricated concrete house structure is a form of construction that involves the industrial production of building components and their assembly on-site, technically falling under the category of prefabricated concrete structures.

I. Development Background and Construction Characteristics
From the late 1980s to the 1990s, China's urbanization accelerated, and prefabricated panel buildings became an important choice for urban construction due to their fast construction speed and low cost. Their core adopts a 'panel-column' system, with exterior walls composed of prefabricated concrete panels and the main structure primarily made of reinforced concrete prefabricated components. The construction process is divided into two stages: factory prefabrication and on-site installation, covering design, manufacturing, transportation, installation, and decoration processes. It offers advantages such as high industrial production efficiency, short construction periods, and minimal environmental impact. Most prefabricated panel buildings constructed in the 1990s were 6-7-story low-rise buildings, featuring standardized designs and flexible interior layouts that could be adjusted according to residents' needs.

II. Service Life and Influencing Factors
Most prefabricated panel buildings constructed in the 1990s are still in normal use today, with an average lifespan exceeding 50 years, and those well-maintained can last 60-70 years. Their lifespan is influenced by two main factors:

1. Design Level: Reasonable structural design, appropriate component sizes, and effective waterproofing measures are crucial. For example, scientific load distribution can avoid structural stress concentration, and waterproofing design can reduce the impact of rainwater erosion on the durability of the concrete.
2. Construction Quality: The manufacturing precision of prefabricated components, the processing techniques for connection joints, and the standardization of on-site assembly directly affect overall stability. If components have defects such as honeycombing and pitting, or if the steel bar anchoring at connections is insufficient, it may lead to cracks or even partial collapses.

III. Technical Advantages and Limitations
This structure achieves component standardization and construction mechanization through industrial production, significantly shortening construction periods and reducing labor costs. At the same time, on-site operations are reduced, minimizing interference with the surrounding environment. However, early technologies had certain limitations, such as transportation of prefabricated components being restricted by size, and the seismic performance of connection joints potentially being weaker than that of cast-in-place structures. However, with technological advancements, modern prefabricated concrete structures have addressed these shortcomings through optimized joint designs and the use of high-strength materials.