For high-rise buildings, there are five main forces that destroy the external wall insulation layer:
1. Seismic force.
Earthquake force will cause extrusion, shearing or deformation of high-rise building structure and thermal insulation surface. The greater the stiffness of thermal insulation surface, the greater the earthquake force, and the more serious the possible damage.
This requires that the external insulation materials of high-rise buildings must meet the principle of flexible gradual change on the premise of considerable adhesion, so as to disperse and absorb earthquake stress, reduce the load on the surface of insulation layer as much as possible, and prevent the insulation layer from cracking, peeling or even falling off in a large area under the influence of earthquake force.
2. Wind pressure.
Generally speaking, positive wind pressure produces thrust and negative wind pressure produces suction, which will cause great damage to the external insulation layer of high-rise buildings.
This requires that the external insulation layer should have considerable wind pressure resistance, and in terms of wind pressure resistance, it is required that the insulation layer has no cavity and no air layer, so as to avoid the damage to the insulation layer caused by the volume expansion of the air layer in the insulation layer under the action of wind pressure, especially under the negative wind pressure.
3. Fire.
High-rise buildings require higher fire resistance rating than multi-storey buildings, and the insulation layer of high-rise buildings should have better fire resistance, and should have the characteristics of preventing fire from spreading and releasing smoke or toxic gases in case of fire.
The strength and volume of materials should not be reduced too much, and the surface layer should not burst or collapse, otherwise it will cause harm to residents or firefighters and cause great difficulties to rescue work.
4. Thermal stress.
Thermal expansion and cold contraction caused by temperature difference will cause the volume change of non-structural structure, which will always be in an unstable state. Therefore, thermal stress is one of the main destructive forces of the external insulation layer of high-rise buildings.
Compared with multi-storey or bungalow buildings, the outer layer of high-rise buildings is exposed to more sunlight and has greater thermal stress and deformation. Therefore, in the design of thermal insulation and crack-resistant structure, the selection of thermal insulation materials should conform to the principle of flexible gradual change, and the deformation ability of outer materials should be higher than that of inner materials.
5. Water or steam.
In order to avoid the damage of water or steam to high-rise buildings, external insulation materials with good hydrophobicity and good steam permeability should be selected to avoid the phenomenon of wall condensation or the increase of moisture content in insulation layer during the migration of water or steam, and to improve the rain erosion resistance and freeze-thaw resistance of external insulation layer of high-rise buildings.
In view of these factors that are easy to damage the external insulation layer of high-rise buildings, special attention should be paid to the following problems in the construction of external insulation layer of high-rise buildings:
1. For the external walls of high-rise buildings, fire prevention measures should be taken, such as setting fire isolation zones.
Fire isolation belt is a fire prevention system that uses incombustible thermal insulation joints in the horizontal direction to prevent the fire from spreading along the external wall or in the external thermal insulation system of the external wall. Commonly used materials include inorganic thermal insulation mortar, foam glass, rock wool, foam ceramics, foam cement and other A-class fireproof materials.
2. The system and the wall at the grass-roots level should be reliably fixed.
High-rise buildings have to bear a large wind load, and the wall part will produce a large negative wind pressure (suction). Therefore, the insulation layer should be reliably bonded with the grass-roots (inorganic materials), especially the use of (organic materials) insulation board, we must pay attention to this link.
3. Paint (or colored mortar) shall be applied to the external surface.
The insulation layer in the system is mostly light and porous material, and its shear strength is low, so brick is not suitable for the facing layer. If you stick tiles, you must have reliable measures to prevent the tiles from falling off and hurting people.
4. The durability of the system should meet the requirements.
Under normal use and maintenance conditions, the service life of external wall thermal insulation engineering should be no less than 25 years.
Shandong Tiandida Building Materials Technology Co., Ltd. (TDD brand), since its establishment in 2008, has been committed to the research, development, production and sales of heat preservation and decoration integrated plates. With more than 20 products and construction patents in the industry, we insist on tailoring the all-round integrated thermal insulation and decoration system scheme for construction projects, and create the value proposition of high-quality complete products in line with the concepts of green, energy-saving, science and technology and environmental protection. Through the joint efforts of the company's employees, TDD thermal insulation and decoration integrated board won many honors and took the lead in passing the national quality management system certification in the industry. Now we have set up offices in Beijing, Shenyang, Zhengzhou and Taiyuan. With dozens of agencies, it has completed nearly 500 large-scale engineering cases nationwide, established a good reputation and become a model in the industry.