| With the continuous development of our country’s economy and society,the country has a high incidence of fire cases,and the situation of fire prevention and control is still very severe.With the development of urbanization,more and more decoration panels have enriched people’s material life while also increasing.More hidden fire hazards are also increased,and the difficulty of fighting fire after a fire occurs.Therefore,the study of the surface burning performance of the board is important and necessary.In addition,the study of fire traces after plate burning is helpful to improve the material burning database,and it is of great significance to determine the cause and spread direction of fire accidents.This article improves the tunnel furnace device in the "ASTM-E84-06 Experimental Method for the Surface Combustion Characteristics of Building Materials".We adds calorimetric equipment and gas analysis equipment,enriches the experimental data,and selects the commonly used blockboard and birch on the market.Six kinds of decoration boards,including plywood,beech wood board,wood veneer,particle board and medium density board,were used as experimental materials for experiments.Analyze the flame spread ability of the board through the flame spread distance,the flame spread index,the farthest crack width,etc.,under the conditions of a wind speed of 1.22m/s,a fire source power of 88 kw,and a burning time of 600 s,the flame spreading ability of birch plywood is the strongest which the fire hazard is relatively large,and the hazard of blockboard and medium-density board is relatively small.The relationship between the flame position and time of the six types of boards in the rapid flame growth stage is derived;through the gas product concentration in the combustion process,Analyzing the surface burning characteristics of the board with data such as heat release rate peak,optical density,smoke production rate,smoke spread index,etc.,it is found that birch plywood is also a relatively hazardous board.Medium density board and blockboard are producing smoke and heat.There is a slight difference in capacity,but over all it is still a relatively less harmful board.Through the thermogravimetric analysis experiment to analyze the pyrolysis ability of the board,it is found that the pyrolysis ability of the medium density board is the strongest,but the thermogravimetric experiment analyzes the pyrolysis ability of the wood under a nitrogen atmosphere.The burning process of the wood also consider factors such as the reaction with oxygen and the heat-generating capacity of the material itself;and the sample of the pyrolysis experiment is very small,which is far from the actual fire scene.Therefore,if we want to evaluate the fire hazard of a material,we still have to choose a test method of tunnel furnace that can measure the fire spreading ability,smoke and heat generation ability.Then compare the images of the burned boards,and summarize the trace characteristics of different boards;analyze the composition of the embers of the boards through infrared analysis experiments,and find that the absorption peaks of the embers of different boards are similar;analyze the microscopic morphology of the burning traces of the boards through the scanning electron microscope experiment It can be found that near the fire source and the middle position of the violently burning plate,the microscopic appearance is severely damaged,and compared to the end of the plate and the middle position of the plate that is not burning violently,the microscopic appearance is clearer,and the gaps between the fibers become bigger. |
