Combustion Characteristics Of Weatherstrip And Their Impacting On Fire-resistant Properties Of Building Energy-saving Windows

Building energy-saving windows are widely used in new residential buildings,about 20%of the total area of the house,it has the characteristics of sufficient lighting and good vision.However,because of its fragility and poor safety,it has become an important part of building fire research.In fire scenarios,the sealing strip filled in the building energy-saving window fails under the action of thermal load,resulting in the cracking and falling off of the whole window.forms a flame spread channel.Therefore,the fire-resistance characteristics of building energysaving windows have an important influence on the spread of outdoor fires to indoors.this paper takes the sealing strip filled in the building energy-saving window as the starting point,combined with the methods of physical combustion experiment and numerical simulation of building energy-saving windows,the fire resistance performance of building energy-saving windows under fire environment is studied.Reveal the influencing factors of its refractory failure,it aims to provide a theoretical basis for the optimization of building energy-saving window materials and the selection of composition systems.In the research of the combustion characteristics of the sealing strip,through thermogravimetric experiments,the pyrolysis characteristics of two typical sealing materials,EPDM strips and expanded graphite strips,which are commonly used in building energy-saving windows,were explored.The components of the samples were obtained separately,revealing the effect of the heating rate on their pyrolysis behavior,the activation energies of the cracking and combustion stages of the sealing strip were solved by the multi-heating rate FWO method.In addition,through cone calorimetry experiments,the combustion characteristics of two types of sealing strips were studied,a high-speed camera was used to study the spread law and shape change of the gas seals placed in the reformed box-type resistance furnace.The results show that under the action of heat load,th e EPDM strip sags inward and releases a lot of smoke;the expanded graphite strip expands outward to generate a large number of worm-like substances.the higher the expansion ratio,the denser the worm-like substances.In view of the fire resistance of building energy-saving windows,this paper studies the fireresistance failure characteristics of 65 series two-glass single-chamber structure aluminum alloy and plastic steel windows building energy-saving inner casement windows.the numerical simulation software FDS is used to simulate and calculate the fire resistance characteristics of building energy-saving windows under different working conditions.the simulation results are compared with the experimental results.Research shows that,When the building energy-saving windows are made of aluminum alloy profiles,the integrity of the building energy-saving windows is lost due to the burning failure of the sealing strips.When plastic steel profiles are used,the building energy-saving windows lose their integrity because the outer frame profiles are deformed by heat.This study uses object combustion test and numerical simulation method to analyze its influence on the fire resistance of building energy-saving windows on the basis of studying the combustion characteristics of the sealing strip.The dominant factors of fireresistance failure of different types of building energy-saving windows are determined,and the research results provide theoretical support for scientifically predicting the fire-resistance failure characteristics of building energy-saving windows in a fire field.