Preparation For Polymer Modified Cementitious Waterproofing Coating And Study On Its Properties And Microstructure

The leakage has become a common fault in the construction quality. It not only disturbs people normal living,working and production order,but also leads to enormous economic loss. Therefore,the building waterproofing plays an important role in the construction. In that it can effectively guarantees the construction's function and prolongs lifespan.The polymer modified cementitious waterproofing coating,which is an emulsion and double ingredient paint,is made up of the polymer latex and inorganic fillers. After coated,the hydration will take place as soon as cement in the composite system contacts with water of the latex. Because the polymer latex is colloid dispersoid,the polymer particles disperse into slurry and absorb on cement,hydrate and other fillers. Along with the water depletes and escapes,the polymer particles close slowly and agglomerate with each other. At last,a continuous film structure comes into being. The film offsets the traditional polymer-cement composite material's defects,such as lack of flexibility and the film's re-solution,and enhances the tensile strength of the coating. It integrates the advantages of organic material as toughness and flexibility and advantage of inorganic material as good durability,so makes composite effect. Moreover,it has other merits,such as high bond strength,innocuity,insipidity and no atmosphere pollution.This paper studies the stability of the waterproofing coatings' slurry and analyzes the different factors that influence the polymer modified cementitious waterproofing coatings. They include the ratio of liquid to powder(L/P),(2) the ratio of cement to polymer(C/P),(3) the dosage of coalescer,the dosage of plastizer,(5) the dosage of dispersant,the type of filler,(7) the type of cement,(8) curing age and rule,(9) the way of film formation and thickness. The results show that the rational L/P and C/P is related to rigidity and flexibility. The coalescer can improve the ability of film formation of the paint and enhance the flexibility of film. Proper plastizer can improve the low temperature performance. The dispersant makes the particles of inorganic filler disper sufficiently. As a result,the paint becomes more homogeneous and stable. Also the different types of fillers and cements can influence the performance of the coating. Moreover both the curing age,rule and the way,thickness of film-formation determine the tensile performance. By comparison with several waterproofing coatings,we find that the hydrate reinforces the film structure and improves the durability. SEM can beused to observe the structure and appearance of the film,XRD to determine the hydrate of cement,IR to analyze the variety of polymer group after coating. At last this article discusses the film-form mechanism and preparation of the waterproofing coating.