Study On Mix Proportion And Properties Of Polymer Modified Mortar In EPS External Thermal Insulating Composite System

External Thermal Insulating Composite System(ETICS) is becoming further widely used in China with the building energy efficiency calling for higher rate. However, for it is still in the preliminary stage of application, lots of quality problems have come up in use especially in southwest area Therefore, the polymer modified mortar, the key technology affecting the property of EPS ETICS, is quite necessary to be optimized in order that a better quality EPS thermal insulating composite system is to be explored.Focusing on the purpose of improvements in construction convenience, flexibility and adhesive ability of polymer modified mortar, the thesis has done some researches on the mix proportion design of four different kinds of polymer in different quantity ratio. The optimum mixing quantity of each polymer is finally designed through the testing of mortar's flexural strength, compressive strength, ratio between compressive and flexural strength, etc. On the basis of the former experiment results, the adhesive ability of four kinds of optimum polymer quantity is tested in contrast with an un-modified mortar, the result of which illustrates that the design of Wacker 5044N with a ratio of 6% perform the best compare with others.The mortar always perform differently in various curing environment, thus a contrasting research has been done on mortar cured in different system and methods. The result has shown that the dry and wet alternant curing system MII is more suitable for the strength development of polymer modified mortar. Besides, the uncovering-curing method shows a higher early compressive strength while covering-curing method a higher evening compressive strength.Super-fine sand is always rich in Chongqing. A research on the super-fine sand used as fine aggregate in mortar, a substitution of quartz sand, is done in the thesis, the result of which shows that super-fine polymer modified mortar has a capacious investigating and application future.According to the final choice of optimum kind and quantity of polymer, with the most appropriate curing system and method, the contrasting experiment between polymer modified and ordinary mortar is done to examine fresh properties, mechanical property, freezing-resistant property, etc. The result illustrates that a great improvement in comprehensive properties of mortar is exhibited in polymer modified mortar in contrast with ordinary one.In the thesis a microcosmic analyzing method SEM is applied to investigate the microstructure difference between polymer modified and ordinary mortar, the result of which indicates that polymer adding into mortar has to some extent changed the internal structure, the hydrating product and adhesive property between cement paste and aggregate, which finally leads to a improvement in both working and using properties.