Fixation of insulation layer of external wall insulation board

The fixed quality of the insulation layer of the external wall insulation board directly affects the stability of the whole system. At present, the fixing method of the insulation layer of the polyphenyl external wall insulation board is usually a combination of adhesion and anchoring. According to JG 149-2003 (thin plaster expanded polystyrene insulation board exterior insulation system), the bolt pull-out force (0.3KN/piece) is calculated by the safety factor of 3 times wind pressure. The number of anchor bolts is : 3 × wind pressure calculated value ÷ 0.3, the results of calculating the number of anchors used in different heights of buildings are shown in the table below.

It can be seen from the table that the anchor bolt is 17 (pieces/m2) on a wall of 20 m height and 29 (pieces/m2) at a height of 100 m. In addition, the number of anchors required to achieve a bond tensile strength of 0.1 MPa is 333/m2, based on the anchor pull-out force (0.3 KN/piece). It is obviously impossible to arrange such a high-density anchor, which on the other hand shows that the real way to improve the stability of the system (wind pressure, etc.) can only be to improve the overall bond strength. The weakest link of the polystyrene board external thermal insulation system is the bond between the adhesive and the thermal insulation layer, which is determined by the strength of the polystyrene board itself. The overall bonding force of the board is proportional to the bonding area. Therefore, increasing the bonding area of the bonding paste and the polystyrene board can improve the adhesion of the polystyrene board and the bonding paste. According to JGJ 144-2004 (Technical Regulations for External Thermal Insulation Engineering), the bonding area is not less than 40%. We change the traditional point-adhesive process to the strip-bonding method, and the cavity on the back of the polystyrene board is evenly distributed. The increase of 10%-20%, and the overall resistance of the polystyrene board to wind pressure is also improved.