Chongqing Brick-Concrete Prefabricated Panel Houses

Brick-concrete prefabricated panel houses in Chongqing generally suffer from structural defects, and reinforcement and renovation require scientific methods tailored to specific issues.

Built in the 1980s and 1990s in Chongqing, brick-concrete prefabricated panel houses commonly exhibit the following structural defects due to limitations in design standards and construction techniques:

1. Wall Defects: The absence of ring beams and structural columns results in poor overall integrity. Mud walls are prone to weathering and spalling, while uneven settlement of mountainous foundations can cause wall cracking.
2. Floor Defects: Insufficient support length for prefabricated floors and cracking between floor panels lead to inadequate load-bearing capacity that fails to meet modern usage requirements.
3. Temporary Building Issues: Illegal prefabricated panel structures, such as those in No. 75 Guihua Road, Shuangjiang Subdistrict, Yunyang County, although intended as temporary housing, pose safety risks when used long-term.

To address wall defects, Chongqing employs three reinforcement methods:

• Planar Wall Closure Reinforcement: Enhances wall crack resistance and load-bearing capacity by adding steel mesh, shotcrete, or carbon fiber sheets.
• Longitudinal and Transverse Wall Tie Reinforcement: Improves overall integrity by adding tie bars or structural columns at wall intersections, preventing collapse risks due to foundation settlement.
• Specialized Load-Bearing Wall Reinforcement: Strengthens locally inadequate load-bearing walls using methods such as steel-encased reinforcement, adding buttress columns, or chemical grouting.

Prefabricated floor reinforcement focuses on three scenarios:

• Support Lengthening Reinforcement: Extends floor support length by inserting rebar or adding concrete pads to improve stress distribution.
• Surface Layer Overall Reinforcement: Creates a composite structure by laying steel mesh and pouring fine aggregate concrete on the floor surface, enhancing overall stiffness and load-bearing capacity.
• Roof Appurtenance Reinforcement: Anchors or adds ties to roof appurtenances such as parapet walls and chimneys to prevent detachment caused by wind vibration or earthquakes.

It is important to note that illegally constructed brick-concrete prefabricated panel houses lack formal design review, making their structural safety unassurable. Even after reinforcement and renovation, strict evaluation of compliance and long-term durability is necessary. Homeowners are advised to prioritize resolving building legality issues through legal channels before commissioning professional institutions for structural safety assessment and reinforcement design.