Long-term Performance Evolution Of The Material And Component Of Hidden Frame Supported Glass Curtain Wall

Glass curtain wall,as enclosure structure,is directly exposed to the environment and subjected to various loads.Their performances deteriorate gradually,which leads to various durability and safety problems such as leakage,vacuum failure,and even component falling.Events such as the falling of curtain wall glass or fanlight are reported frequently.To reduce or eliminate these potential threats,the glass curtain walls need scientific maintenance and timely repair and replacement,which should be based on the information of long-term performance evolution of glass curtain wall.This paper presents the research of the long-term performance evolution of glass curtain wall,which is focus on the deterioration behavior of panels,structural sealants and components of glass curtain wall and based on experiment research and numerical simulation.The main research contents and achievements are as follows.(1)The erosion behavior of glass panels under different erosion velocities and angles was studied by gas-solid two-phase flow erosion tests,which simulate wind-sand environment.The evolution of quality,visible light transmittance and effective area ratio of glass panels were tested,and the law of degradation of glass panels caused by erosion was obtained.And the surface morphology of glass panels was observed by scanning electron microscopy to analyze the micro-mechanism of the erosion.Based on the above results,the failure prediction models of panel safety and applicability were established respectively and a model based on the total kinetic energy of erosion particles per unit time is established,which is about the erosion time relationship between laboratory conditions and service conditions.(2)Accelerated aging tests and natural exposure tests of structural sealants were carried out,where sealants are subjected to the coupling effect of the environment and load,using the newly developed loading device.Strength,modulus and maximum strength elongation of structural sealants at different aging times were measured,and the stress-strain curves of aged sealants were obtained.The deterioration mechanism of structural sealants under the coupling of environment and load was discussed,based on the chain-scission and cross-linking reaction of sealant polymers.By comparing the data of artificial accelerated aging test,natural exposure test and existing literature,it is concluded that the effect of environment promotes the chain-scission reaction and the effect of load action promotes the cross-linking reaction.(3)The accelerated aging test of curtain wall component was carried out,where the component is subjected to ultraviolet irradiation and moisture,and the deflection of measuring points on the surface of the panel of the curtain wall component was measured after 1000 hours ageing.A numerical model of curtain wall components was established,where the data of long-term performance test of structural sealants were input as original information of sealant materials,and the evolution of deflection of measuring points on the surface of the panel with deterioration of sealants was analyzed.Based on the validation of the experimental results,the numerical model was used to analyze the mechanical responses of the components with sealants in different deterioration degrees under the designed wind pressure...