Nowadays, high-rise buildings are installed with external metal carved panels. The external metal carved panels can play the role of thermal insulation and external wall protection. It can extend the use of external brick brick concrete materials. life. However, with the extension of the use time, the metal engraved sheet material of the exterior wall will also appear aging phenomenon, what are the reasons for its aging? Here we briefly introduce it, roughly divided into five aspects.

    1. Thermal stress. The thermal expansion and contraction caused by the change of temperature difference will cause the volume change of the non-structural structure of the outer wall metal engraved plate, so that it is always in an unstable state, so the thermal stress is one of the main destructive forces of the metal engraved plate of the outer wall of the high-rise building. . Compared with multi-storey or bungalow buildings, high-rise buildings are more sensitive to sunlight, more thermal stress and more deformation. Therefore, when designing thermal insulation and crack-resistant structures, the selection of external metal carved panels should meet the principle of flexible gradual change. The deformability of the outer layer material should be higher than the deformability of the inner layer material.

    2, wind pressure. Generally, the positive wind pressure generates thrust, the negative wind pressure generates suction, and the outer insulation layer of the high-rise building will cause great damage. This requires the outer insulation layer to have considerable wind pressure resistance, and it is resistant to wind pressure. In other words, the insulation layer is required to have no cavity and eliminate the air layer, thereby avoiding the volume expansion of the air layer in the insulation layer under the wind pressure, especially the negative wind pressure state, thereby causing damage to the insulation layer.

    3. Earthquake force. Seismic forces can cause extrusion, shearing or distortion of high-rise building structures and insulation surfaces, and the greater the rigidity of the insulation surface, the greater the seismic force that can be withstood, and the more serious the damage can be caused. This requires the high-rise building exterior metal carved panels to meet the principle of flexible gradual change under the premise of considerable adhesion, in order to disperse and absorb the seismic stress, minimize the load on the surface of the insulation layer, and prevent the insulation under the influence of seismic force. The layer has a large area of cracking, peeling and even falling off.

    4. Water or steam. In order to avoid the damage of high-rise buildings caused by water or steam, the external thermal insulation material with good water repellency and good water vapor permeability should be selected to avoid the condensation of water or water vapor during the migration process or the internal moisture content of the insulation layer. Phenomenon, improve the resistance to rain and water erosion and freeze-thaw resistance of metal carved panels on the exterior walls of high-rise buildings.

    5. Fire. High-rise buildings require higher fire rating than multi-storey buildings. The insulation of high-rise buildings should have better fire resistance and should have the characteristics of preventing fire spread and preventing the release of smoke or toxic gases in case of fire. The strength and volume of the metal engraved board material can not be reduced too much, and the surface layer is free from bursting and slumping, otherwise it will cause damage to the residents or firefighters and cause great difficulties to the rescue work.