Mesh cloth function: alkali-resistant glass fiber mesh cloth is the strengthening material of the external wall insulation surface layer, the main role is: to improve the mechanical strength of the surface layer, to ensure the continuity of the resistance of the finish layer, to disperse the shrinkage pressure of the surface layer and insulation stress, to avoid stress concentration, to resist the natural temperature, humidity changes and accidental impact caused by the surface layer cracking. The alkali-resistant glass fiber mesh cloth plays an important function and role in the external insulation system, so the choice of good glass fiber mesh cloth is also an important part of ensuring the comprehensive quality of the external insulation system.
Mesh cloth standard: the national current exterior wall insulation technical standards (JG149-2003): glass fiber mesh warp and weft alkali-resistant tensile breaking strength shall not be less than 750N/50mm, alkali-resistant tensile breaking strength retention rate shall not be less than 50%, the weight per square meter ≥ 130 grams. And JG158-2004 glass fiber mesh warp and weft alkali resistance tensile breaking strength shall not be less than 1250N/50 mm, alkali resistance tensile breaking strength retention rate shall not be less than 90%, the weight per square meter ≥ 160 grams.
And the current market for external wall insulation system in China's grid cloth per square meter weight are in 130g or so, the strength is generally low, its normal fracture strength of only 1000N/5cm, or even lower. For this reason: the technical index of the mesh cloth for external wall insulation project is required to be standardized, and the qualified confirmation of the purchased alkali-resistant glass fiber mesh cloth must be made before use. In the external wall insulation crack control, not only requires the insulation layer material to have a certain tensile strength and ultimate tensile, but also requires the anti-crack protection layer material to have sufficient tensile strength. For this reason, it is necessary to pay attention to whether the tensile strength of alkali-resistant glass fiber mesh itself meets the standard when choosing alkali-resistant glass fiber mesh.
The use of alkali-resistant glass fiber mesh compounded in the plastering mortar can effectively increase the tensile strength of the protective layer on the one hand, and on the other hand, because it can effectively disperse the stress, it can disperse the original wider cracks that may arise into many finer cracks, thus forming its anti-cracking effect. The surface coating material and the amount of coating have a more important significance to the alkali resistance of glass fiber mesh fabric, while the glass fiber variety has a decisive significance to the long-term alkali resistance.
Glass fiber mesh fabric in the process of use:
The lap width between alkali-resistant mesh cloth is not less than 50mm , and the alkali-resistant mesh cloth at the shaded corners should be stubble lap, whose width is ≥50mm, and at the sunny corners ≥200mm. During the construction, the alkali-resistant mesh cloth should be paved smoothly, without wrinkles, and the mortar fullness up to , while smoothing, straightening, keeping the squareness and verticality at the shaded corners.
