Comparison of advantages and disadvantages of the

Stone, glass, metal curtain wall: comparison of advantages and disadvantages

I. advantages and disadvantages of stone curtain wall

advantages:

1. Natural material, bright and translucent, hard and permanent, noble and elegant

2. Frost resistance: when the stone is wet, it can resist freeze-thaw without significant damage. This property is called frost resistance. When the temperature of water in the pores of rock is as low as minus 20 ℃, it freezes, and the expansion of water in the pores is 1/10 larger than the original volume. If the rock cannot resist the force caused by this expansion, it will be destroyed. Generally, if the water absorption is less than 0. 5%, regardless of its frost resistance

3 compressive strength: the compressive strength of stone will vary due to mineral composition, crystal thickness, uniformity of cementation material on November 2, 2015, load area, load action and cleavage angle, etc. If other conditions are the same, the dense materials with fine crystalline particles and bonded with each other usually have high strength. There is no difference in compressive strength (extremely low water absorption) between dry and saturated water of dense volcanic rocks. If they are porous and water resistant cemented rocks, there is a significant difference in dry and wet strength

disadvantages:

1. There are many serious dangers of heavy stone as the outer wall of high-rise buildings. The bidding in the construction industry is not completely standardized. Many stone curtain wall projects are those who have the lowest cost and win the bid. There are individual subcontracts. In this way, the bid is won at a low price. In order not to lose money, it is necessary to steal work and materials. There are indeed many low-grade granites with a surface bonding strength of 100 ~ 200 yuan per square meter for high-rise (50 ~ 100 meters high) stone curtain walls. Isn't it dangerous

2. Many design institutes are not familiar with curtain walls, so they can draw a unified range on the drawings and indicate what curtain walls. Stone curtain wall is no exception. The successful 1.2 experimental space can be manually adjusted. The curtain wall company designs it by itself. Some design institutes ask the structural engineer to carefully review it, but most design institutes take a formal review, and the design can't be controlled. Isn't it dangerous

3. For all construction projects, the state requires a supervision company to be responsible for the quality, which is completely correct and necessary, and is the key to ensure the project quality. Unfortunately, many supervision engineers are civil engineers, who do not understand curtain walls, let alone stone curtain walls. This is because there is a lack of curtain wall teaching materials in the supervision training materials, and many supervisors are retired technicians. How can we control the final quality without training and understanding the supervision of curtain wall? The quality inspection stations of buildings around the country often encounter various difficulties in quality acceptance because they learn little about new technologies

4. The fireproof performance of stone curtain wall is very poor, especially in high-rise buildings, fires are generally ignited indoors. The fire in the building will raise the temperature of the stainless steel plate and metal structure hanging the stone plate, soften the steel and lose strength, and the stone plate will form a "rain" from the high-rise, which will not only cause danger to pedestrians, but also cause difficulties in fire fighting. This is just like the collapse of the world trade center in the United States, because the world trade center is all steel structure, the steel softens at high temperature and loses strength, and the World Trade Center collapses from top to bottom

II. Advantages and disadvantages of glass curtain wall

advantages:

glass curtain wall is a new type of wall in contemporary times. The biggest feature it gives to architecture is to organically integrate architectural aesthetics, architectural functions, architectural energy conservation and architectural structure. Buildings show different colors from different angles, and give people dynamic beauty with the changes of sunlight, moonlight and lighting. Magnificent glass curtain wall buildings have been built in major cities on all continents of the world, such as the world trade center in New York, the oil building in Chicago and the Sears building. Bank of China Building in Hong Kong, Great Wall Hotel in Beijing and Lianyi building in Shanghai have also been adopted

disadvantages:

glass curtain walls also have some limitations, such as light pollution, large energy consumption and so on. In addition, the bright and transparent natural beauty of glass curtain wall is not resistant to pollution, especially in the northern region where the atmosphere contains a lot of dust, the air pollution is serious, and the drought and little rain, the glass curtain wall is very prone to dust and dirt, which can not only increase the "light" but also lose the "face" for the urban landscape. The materials used are inferior, the construction quality is not high, the color is uneven, and the waves are different. Due to the uncontrollability of light reflection, the light environment is messy. However, with the continuous emergence of new materials and new technologies, these problems are gradually incorporated into the comprehensive research system of building modeling, building materials and building energy conservation, and are discussed in depth as a whole

III. advantages and disadvantages of metal curtain wall

advantages:

leading products in metal curtain wall? Aluminum curtain? So far, the aluminum curtain wall in the metal curtain wall has been dominant in the metal curtain wall. The lightweight material reduces the load of the building, which is difficult to guarantee the product quality, and provides good selection conditions for high-rise buildings; Excellent waterproof, antifouling and anti-corrosion properties ensure the lasting renewal of the external surface of the building; Processing, transportation, installation and construction are relatively easy to implement, providing strong support for its wide use; The diversity of colors and their combination and processing into different appearance shapes have expanded the design space of architects; High performance price ratio, easy maintenance, long service life, in line with the requirements of the owner. Therefore, aluminum curtain wall, as an architectural form with great impact, is favored

disadvantages:

1. The deformation resistance of the curtain wall system: scientific mechanical calculation must be carried out for each important part of the curtain wall system, considering the impact of wind pressure, self weight, earthquake, temperature and other effects on the curtain wall system, and carefully check the embedded parts, connection system, keel system, panel and fasteners to ensure the safety of the curtain wall

2. Whether the plates adopt floating connection; The floating connection ensures the resilience of the curtain wall after deformation, ensures the integrity of the curtain wall, and will not cause the deformation of the curtain wall due to the force, so as to avoid the bulge or depression of the curtain wall surface

3. Fixing method of plates: the fixing method of plates plays a decisive role in the installation flatness of plates. The inconsistent stress of each fixed point of the plate will cause the deformation of the surface material and affect the exterior decoration effect, so the fixed method of the plate must adopt the fixed method of fixed distance compression to ensure the flatness of the curtain wall surface

4. Whether there are reinforcement measures at the edge removal of composite surface material: because the folded edge of composite panel material only retains the thickness of the front plate, the thickness becomes thinner and the strength decreases, so reliable reinforcement measures must be taken for the edge removal

5. Whether stiffeners are reasonably set on the back of the plate to increase the strength and stiffness of the plate. The arrangement distance of stiffeners and the strength and stiffness of stiffeners must meet the requirements to ensure the use function and safety of curtain walls

6. Whether the waterproof sealing methods are reasonable: there are many waterproof sealing methods, including structural waterproof, internal waterproof, and glue sealing. The prices of different sealing methods are also different. Choose the appropriate sealing method for the project to ensure the function and exterior decoration effect of the curtain wall

7. Whether the selected materials meet the specifications, standards and design requirements