1.The anti-cracking property of polymer plastering mortar and cement putty focuses on the selection of raw materials. Selecting high-quality raw materials, fully understanding the properties and action mechanisms of various raw and auxiliary materials, scientific formula, and selecting high-quality products with strong functionality and stable and reliable performance can better prevent the occurrence of cracks.
2.Choose additives with stable quality, such as RDP (FWD 1200), HPMC (FWD MP 100EA), Defoamer, PP fiber and so on
3.The architectural design, especially the design of the exterior wall insulation structure, should be rigorous, and the foundation settlement, earthquake resistance, wind pressure resistance, stress release, environmental impact and other issues should be fully considered.
4.In terms of construction technology, in order to avoid large shrinkage force of plastering mortar and exterior wall putty, each scraping should be thin rather than thick. The plastering mortar should not exceed 2.5 mm layer thickness each time, and the exterior wall putty should not exceed 1 mm layer thickness each time.
5.It is not advisable to use excessive amounts of polyvinyl alcohol, latex and other highly closed adhesives in dry-mixed plastering mortar, exterior wall putty or common cement. Such adhesives can quickly form a film and seal the micropores of cement, and aggravate the shrinkage of cement, forming a "hard shell" phenomenon, forming a large strength difference with the base layer, that is, the surface layer strength greatly exceeds the base layer strength, which is easy to cause cracking, hollowing and falling off. In addition, once the micropores of cement mortar are completely sealed, this will not only affect the full hydration of cement, but also make the cement mortar lose its "free breathing" and self-maintenance functions. The bad components in the wall cannot be discharged through the micropores with water, and the service life of the wall will be poor.
5. The design and construction of the exterior wall insulation layer did not take into account the release of stress in the insulation layer. The entire wall surface was completed in one go from top to bottom, with several or dozens of floors, and no expansion joints were designed. Once a large stress is generated, the entire insulation layer, including the plastering mortar, exterior wall putty and paint layer, will inevitably produce cracks. Polymer dry-mix plastering mortar and exterior wall putty involve many aspects. To solve this problem, we must work together from multiple aspects such as raw materials, product quality, architectural design, engineering construction, and quality management, use all technical means, combine existing successful experiences, and proceed from reality and consider the long-term. It should be practical, economical, and easy to operate.
