The following is the content related to PC exterior wall technology suitable for steel structure buildings brought to you by Zhongda Consulting for your reference.
2. Column-shaped and beam-shaped PC exterior walls can be used to create the appearance effect desired by the architect:
Selection of joint mechanics mode for PC exterior walls:
It can be divided into the following three types. No matter which type is used, the movement of the wall panel in the "indoor and outdoor direction" is not allowed, it must be restricted and fixed, and it must be able to resist positive and negative wind pressure. The sliding dimensions of the sliding holes of the wall plate joint iron parts must also consider the dimensional requirements of earthquake (including wind) sliding + manufacturing errors + construction site errors (including the errors of the main structure itself).
1. Horizontal sliding type (sliding): The movement mode of load-bearing iron parts when encountering earthquake or wind force is horizontal sliding. Semi-wet PC exterior walls all adopt this type of movement. The wide version generally adopts horizontal sliding type. Sliding type.
2. Rolling type (rocking): The load-bearing iron parts are rotated and rolled when encountering earthquake or wind force. Tall and narrow versions generally adopt rolling type. When rolling type joints are used, inspection is required. Check the shear resistance of vertical joint caulking materials.
3. Fixed type (fixing): All iron parts move in a fixed manner when encountering earthquake or wind force. Basically, the wall version moves with the main structure. Generally speaking, like the balcony version Wall panels such as (no contact between top and bottom), small corner panels with pillars (stick to the pillars and move together) and other types of wall panels are fixed type.
Waterproofing methods for PC exterior walls:
Prefabricated exterior walls are generally designed using non-load-bearing curtain wall systems. When affected by earthquake force or wind, the reliable unit wall version To absorb the displacement of components, joints are often opened on four sides (dry wall) or three sides (semi-wet wall), and elastic caulking glue is used to absorb the displacement of earthquake force and wind force.
The patented design of sandwich insulated PC exterior walls developed by Runtai to reduce the dislocation and deformation of internal and external leaves:
Exterior sandwich insulated PC wall panels overcome the limitations of traditional exterior wall insulation The insulation layer is easy to fall off and condensation is easy to form in the inner insulation room. The middle layer is made of XPS (extruded polystyrene foam) insulation board with fire resistance level B1, but it is wrapped with reinforced concrete layers inside and outside. The overall fire resistance of the wall panel can reach Non-combustible Class A material, enhanced fire protection effect. In order to reduce the dislocation deformation between the inner and outer leaves of the sandwich insulation wall panel, Runtai added galvanized steel bars to the iron parts of the wall panel to connect the inner and outer leaves of the wall panel. By analyzing a PC wall panel with a length and width of 3 meters, an outer leaf plate thickness of 60mm, a thermal insulation layer thickness of 50mm, and an inner leaf plate thickness of 90mm, the hoisting misalignment deformation value of the wall panel was greatly reduced, from 0.59mm to 0.13 mm. Trial calculation of PC exterior wall panels shows that a small amount of steel bars has little impact on the overall thermal insulation performance of the sandwich insulation wall. The heat transfer coefficient of the wall panels only increases by 0.001W/(m.k), which has almost no impact on building energy conservation. According to the latest energy conservation requirements GB50189- Table 3.4.1-2 of the 2015 Public Building Energy-saving Design Standard for exterior walls (including non-transparent curtain walls) meets the design requirements of heat transfer coefficient ≦1.0 in hot summer and cold winter areas. This process improvement patent was approved by the national authorization announcement on December 2, 2015, and the patent number is "ZL201520618925.2".
The construction method of PC exterior wall is completed by the factory:
PC exterior wall can still complete all decoration work in the factory for steel structure buildings, and it is purely hoisting and installation at the construction site. In the assembly work, since the steel structure is very suitable for the combination of iron parts, it can greatly reduce the amount of construction work on the construction site and improve the industrialization of the construction site.
The applicable scope, application conditions and limiting factors of PC exterior walls for different steel structure buildings:
There is no unified classification of steel structure buildings in China, and they can generally be divided into plate and shell steel structures. , light residential steel structure, industrial factory steel structure, multi-high-rise civil building steel structure, super high-rise building steel structure.
PC exterior walls are basically suitable for exterior wall enclosure of steel structure buildings. External sandwich insulation wall panels are like steel structure coats, wrapping and enclosing the steel structure, and the continuously installed insulation layer is ideal for indoor environments with thermal insulation requirements. It is also very beneficial, and the external wall panel system with multi-channel waterproof and water-conducting design can solve the common problem of external wall seepage in current projects. In addition, due to the diversity of external pre-embedded tiles, stones, and metal decorative strips, the applicability of internal sandwich insulation, good fire protection and non-combustibility, and the ability to last as long as the building, it can be widely used in multi-high-rise civil buildings. The steel structure is only due to the shortcomings of the self-weight of the PC exterior wall (the unit weight of a 20cm thick PC sandwich insulated exterior wall with 6cm insulation material, 5cm and 9cm is about 360kg/m2, which is about 6 to 8 times the self-weight of a glass curtain wall or metal curtain wall) ) and the cost of producing PC curved wall panels is too high. Therefore, PC exterior walls are less suitable for shell steel structures, light residential steel structures, industrial plant steel structures and super high-rise building steel structures.
Although domestic design institutes currently have less experience in the design of PC exterior walls in steel structure buildings and have not had the cooperation of prefabricated professional contractors before, there are few project examples, but due to the green and energy-saving characteristics of PC exterior walls and The cost is lower than that of glass curtain wall, the diversity of exterior decorations and the fire resistance and durability of internal sandwich insulation have made it widely used in Taiwan, Europe, the United States and Japan. It is hoped that through the sharing of this article, domestic owners and design institutes can make planning and design decisions There is one more choice for the exterior walls of steel structure buildings, which will simultaneously promote the development of domestic architecture.
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