How can we prevent thermal insulation mortar cracking? Shandong thermal insulation mortar related personnel to tell you about this problem.
Now in the northern cities of our country, in order to improve the cold-proof effect of houses. Many buildings have been installed with inorganic thermal insulation mortar. In fact, the inorganic thermal insulation mortar of buildings is a measure of fixing insulation materials and building walls together to achieve thermal insulation or thermal insulation. But we sometimes crack in the construction of exterior wall insulation. What is the reason?
Firstly, cracks caused by incomplete external insulation will also cause cracks in insulation mortar. In the external wall insulation, we often pay attention to the overall wall insulation, but neglect the parapet, canopy, tiger window, convex window, external balcony and other parts of the insulation, which cracks or reduces the service life. In the place where the insulation layer is changed from other materials, because the density difference between the insulation layer and other materials is too large, it determines that the elastic modulus and linear expansion coefficient between materials are also different, and the deformation under the action of temperature stress is also different. It is very easy to produce surface cracks in these parts. At the same time, waterproofing treatment should be considered to prevent water intrusion into the insulation system, avoid the damage of the system caused by frost heave, and affect the normal service life of the system and the durability of the system.
Secondly, ordinary cement mortar itself is prone to produce various shrinkage deformation, and there is a contradiction between short period of strength growth and long period of volume shrinkage. Under restraint conditions, when the tensile stress formed by volume shrinkage exceeds the tensile strength of cement mortar, cracks will appear. The main structure protected by thermal insulation layer is less affected by temperature deformation, while the leveling mortar of 20-30mm is located on the outer side of the polystyrene board with great thermal resistance, which results in large deformation due to the influence of environmental temperature. The cement material on both sides of the polyphenyl board is affected by ambient temperature difference, which results in relatively large deformation difference and cracking. In addition, because the flatness of insulation board is difficult to control, it will cause uneven plastering thickness, local shrinkage and uneven temperature stress, which will lead to cracks.