Now high-rise buildings in the construction will be installed on the wall insulation board, that can play the role of heat preservation and heat preservation of external wall is a protective effect, can extend the use life of the outer wall body brick concrete materials. But with the use of time to extend the wall body heat preservation material will appear aging phenomenon, which is the reason for its aging, which we briefly introduced, roughly divided into five aspects.
1, thermal stress. Caused by the temperature change of the thermal expansion and contraction, can cause changes in the volume of non structure, which is always in a state of instability. Therefore, the thermal stress is the high-rise building exterior insulation layer is one of major damage strength. Compared to the multi-storey or cottage building, high-rise building due to the outer layer of the acceptance of a stronger, more heat stress, deformation is also greater, and thus in the thermal insulation design, the use of thermal insulation material should meet the principle of flexible gradient, the deformation of the outer material should be higher than the deformation of the inner material.
2, wind pressure. Generally speaking, the positive pressure, negative pressure suction, high building insulation layer will cause great damage, which requires external insulation layer should have a considerable anti wind pressure, and on the wind pressure, the insulation layer without cavity, put an end to the air layer, and avoid the air layer in the air pressure in the air layer, the insulation layer is destroyed.
3, seismic force. Seismic force can lead to the high rise building structure and insulation surface layer of the extrusion, shear or distortion, and the insulation layer of the more rigid, the larger the seismic force, the damage may be more serious. The exterior wall of a high-rise building external thermal insulation material in under the premise of adhesion, must meet the principle of flexible gradient, to disperse and Xiaona seismic stress, to minimize thermal insulation layer on the surface of the load and prevent under the earthquake effect of thermal insulation layer of large area cracking, peeling or even fall off.
4, water or water vapor. In order to avoid the damage of high-rise building water or steam should choose good hydrophobicity, the water vapor permeability of insulation materials, avoid water or water vapour in the migration process appear wall condensation or an insulation layer internal moisture content increased, the increase of high-rise building external thermal insulation layer of resistant rain erosion and frost resistance.
5, fire. High-rise building than the multi-storey building fire rating requirements higher, high-rise building insulation layer should have better resistance to fire function, and should have in case of fire prevent fire spread and prevent the release characteristics of smoke and toxic gases, material strength and volume can not afford the loss reduce too much, surface, no crack, no collapse, otherwise, it will to the residents or firefighters damage, causing great difficulties to the rescue work.