Study On The Adhesive Effect Of External Thermal Insulation System Under Dreezing And Thawing Cycles

As an important mean to achieve architecture energy efficiency, external thermalinsulation system has been widely attention and used worldwide. However, exteriorinsulation technology used in engineering generally operated according to engineeringexperience, which lacked the in-depth study to guide the construction. This paper aimed atexternal thermal insulation cracking and dropping caused by seasonal freezing and thawingcycles. The major contributions were summarized as follows by experimental research andtheoretical analysis.(1) According to the tension test and shear test of rock wool, XPS board and TDFboard external thermal insulation under normal, this paper discovered that the systemfailure surface located in the insulating layer, the bonding layer and the interface betweenthem; The adhesive about the tension and shear adhesive strength of three kinds of externalthermal insulation show that the adhesive strength of TDF system occupies first place, andXPS system comes second.(2) Analysis of three exterior insulation system freeze-thaw and gas freeze cycles testshowed that with the increasing times of freeze-thaw and gas freeze cycles, adhesivestrength of exterior insulation system is decreasing and the losses is increasing. However,the influence degree of freeze-thaw and gas freeze cycles were different, and freeze-thawcycles had more influence. This rule did not vary with the different heat insulators.(3) Combined with theoretical analysis, this paper came to a strength degradation ruleof external thermal insulation system under freeze-thaw and gas freeze cycles. And furtheranalysis the degradation mechanism basis on the molecular motion and mechanics.The comparison and analysis showed that TDF board external thermal has the bestadhesive strength and rock wool system has the worst whatever under normal, freeze-thawor gas freeze cycles. This paper based on the results of analysis and integrated withoperational processes in engineering, optimal the suitable bonding mode and the matters need attention, which provided theoretical basis for the application of external thermalinsulation system.