1. Reserved holes for outer frame wall accessories
If steel pipe scaffolding is used to protect the wall, according to the "two-step three span" arrangement of the connecting wall part, the prefabricated wall should reserve no less than 75 steel pipe perforations in advance.
2. The insulation layer at the corner is exposed
In the design of the outer wall of the middle layer of the project, the yin-yang angles of the building were not correctly connected, resulting in insulation layer leakage. Considering that the external wall insulation material itself has certain water absorption and permeability, there is a risk of leakage in the future.
3. Internal connector insulation issues
After the project design is completed, set the insulation length to 220mm. The design intention is to set up internal steel plate connectors. The problem is as follows:
(1) Will the rigid joints of external wall insulation materials rupture due to local excessive stress (structural inspection is required);
(2) The thickness of the bolts in the joint is about 20mm, and the insulation is increased by more than 60 times, which leads to the bias of the cast-in-place steel bars or the failure of the protective layer.
(3) This type of connector and bolt are bulk consumables, which increases the construction cost of the project.
4. The steel bars are insufficient to connect the working surface.
Construction: The joint moves outward, and the pre embedded height of the bolt is 300mm. The pre embedded holes for woodworking screws are incorrect to avoid "fighting".
5. Insulation leakage of expansion joint
In a project, the external wall insulation at the expansion joint of two units has not yet been completed, and there is a risk of leakage in the future.
Treatment: Use at least 50mm of concrete on the insulation end.
6. T-shaped exterior wall issue
The balcony wall outer panel of a certain project has a "T" - shaped node and adopts the design method of external wall cantilever. The problem is as follows:
(1) The outer wall and pages are easy to expand and cannot strengthen the rear edge.
(2) Once the overhang on the outer page increases, it becomes difficult to repair.
Processing: Reserve wall joints and 250mm cracks at the connection between the balcony wall and the exterior wall for on-site construction.