Research On The Coupling Action Of Temperature And Load Of The Outer Surface Of External Wall With Outside Lightweight Thermal Insulating Layer

Combing the lightweight materials with traditional wall materials into use and improving thermal insulating properties of the architectural periphery protect system, has become one of the most important measures to reduce architectural energy consumption. Exterior insulation system has been used more and more widely because of its good thermal insulation and low cost, which has played an important role for promoting building energy saving. However, with the use of delivery of a large number of engineering project, the limitations of external wall with outside lightweight thermal insulating layer also gradually revealed, especially the phenomenon such as surface cracking and shedding of coating, which has become common quality defects. In view of the above questions, this paper tries to discuss and study the external insulation wall damage evolution mechanism as follows.(1) Theory analyzing and studying the working state of external wall with outside lightweight thermal insulating layer under different affecting factors.(2) Experimental study physical and mechanical performance of external thermal with different protective materials in multi-factor coupling action of temperature and structural loads. Artificial lee simulate the influence factors. Do experiment on external thermal under temperature action and coupling action of temperature and structural loads, and obtain each function layer stress-strain data of external thermal, then do analysis on the test data.(3) According to the theory analysis and material test data, using the finite element program-AN SYS to analyze the thermal field distribution and stress-strain variation law. then compared with the results of experiment to deduce the damage evolution mechanism of external thermal wall surface.Shown from the results of experiment and numerical simulation analysis:(1) Directly pasting of materials with different physic-mechanical properties is the internal cause of external thermal wall surface damage. The parameter of external thermal such as modulus of elasticity, coefficient of heat conductivity, coefficient of thermal expansion varies considerably, and the ability of coordination is poor. The limit value of ultimate limit state and serviceability limit state is all low, and the wall surface damages easily.(2) The dead load of outside facing and external loads of temperature, wind and others is the external cause of external thermal wall surface damage. External thermal perennially endure the influence of external environment factors so that it is in the complex stress state of pull, pressure and shear. In multi-factor coupling action of alternately repeatedly, ultimate limit state and serviceability limit state are easy to be exceeded, and it will cause cracking, shedding and any other problem of external thermal wall surface.