口房间内局部燃烧向全室性燃烧过渡的这种现象称为轰燃。轰燃是室内火灾最显著的特征之一，它标志着火灾全面发展阶段的开始。对于安全疏散而言，人们若在轰燃之前还没有从室内逃出，则很难幸存This phenomenon, commonly called flashover, is the transitionfrom the local combustion to the whole combustion. Flashover isone of the most prominent features of indoor fire, it marks thebeginning of the full burning stage. For safe evacuation, it isdifficulttosurvive,if peoplehavenotbeenout oftheroombeforetheflashover.轰燃的特征Characteristicsofflashover：口室内可燃物猛烈燃烧：Fierceburningof the indoorfuel口火灾温度呈直线上升并达到最高点The temperature rise straightly up to the highest point口燃烧稳定，燃烧速度几乎不变。可燃物烧毁质量占火灾烧毁总质量的80%The combustionis stable with a constant speed.The burning mass is80%ofthetotalmassinfire
房间内局部燃烧向全室性燃烧过渡的这种现象称为轰燃。轰燃是室内火 灾最显著的特征之一，它标志着火灾全面发展阶段的开始。对于安全疏散 而言，人们若在轰燃之前还没有从室内逃出，则很难幸存。 This phenomenon, commonly called flashover, is the transition from the local combustion to the whole combustion. Flashover is one of the most prominent features of indoor fire, it marks the beginning of the full burning stage. For safe evacuation, it is difficult to survive, if people have not been out of the room before the flashover. 轰燃的特征 Characteristics of flashover： 室内可燃物猛烈燃烧: Fierce burning of the indoor fuel 火灾温度呈直线上升并达到最高点 The temperature rise straightly up to the highest point. 燃烧稳定，燃烧速度几乎不变。可燃物烧毁质量占火灾烧毁总质量的80% The combustion is stable with a constant speed. The burning mass is 80% of the total mass in fire
口火灾衰退阶段firerecessionstage随着室内可燃物的不断减少，火灾燃烧速度递减，进入熄灭阶段With the decrease of indoor fuel, the burning rate is decreasingand enters the quenching stage特征Characteristics：口室内可燃物减少，温度开始下降the indoor fuel decreases and the temperature starts to drop口温度下降的速度与火灾持续时间有关，火灾持续时间长，温度下降速度小，火灾持续时间短，温度下降速度大The drop speed of temperature is related to the duration of fire, the longerduration of fire is, the lower the temperature drops. Conversely, thetemperature drops faster, when the fire duration is short.口火灾衰退阶段的初期，温度仍然很高，火势很猛，仍对周围有很多威胁。Intheearly stage of fire recession,thetemperature is still high andthe fireis fierce, which is still a lot of threats to the surroundings
火灾衰退阶段 fire recession stage 随着室内可燃物的不断减少，火灾燃烧速度递减，进入熄灭阶段。 With the decrease of indoor fuel, the burning rate is decreasing and enters the quenching stage. 特征 Characteristics： 室内可燃物减少，温度开始下降 the indoor fuel decreases and the temperature starts to drop 温度下降的速度与火灾持续时间有关，火灾持续时间长，温度下降速度小， 火灾持续时间短，温度下降速度大 The drop speed of temperature is related to the duration of fire, the longer duration of fire is, the lower the temperature drops. Conversely, the temperature drops faster, when the fire duration is short. 火灾衰退阶段的初期，温度仍然很高，火势很猛，仍对周围有很多威胁。 In the early stage of fire recession , the temperature is still high and the fire is fierce, which is still a lot of threats to the surroundings
6.1.3.建筑材料的耐火性能Fire-resistance of building materials材料的耐火性能Fireresistanceofthematerials口材料的燃烧性能Combustionproperties可燃性，火焰特征，燃烧速度，发热量，燃烧方式等combustibility,flame characteristics,combustion speed,calorificvalue,combustionmodeetc.可分为非燃烧体、难燃烧体、可燃燃烧体和易燃烧体Building materials are classified as non-combustible,difficult-burning,combustibleandeasy-combustiblematerials口材料的导热性Thermalconductivity导热性好的非燃烧材料，往往耐火防火性能差Non-combustible material with good thermal conductivity oftenhasapoorfireresistanceperformancesuchassteel.口材料的隔热性能thermalinsulationperformance
6.1.3.建筑材料的耐火性能 Fire-resistance of building materials 材料的耐火性能 Fire resistance of the materials 材料的燃烧性能 Combustion properties 可燃性，火焰特征，燃烧速度，发热量，燃烧方式等 combustibility, flame characteristics, combustion speed, calorific value, combustion mode etc. 可分为非燃烧体、难燃烧体、可燃燃烧体 和易燃烧体 Building materials are classified as non-combustible , difficultburning, combustible and easy-combustible materials. 材料的导热性 Thermal conductivity 导热性好的非燃烧材料，往往耐火防火性能差 Non-combustible material with good thermal conductivity often has a poor fire resistance performance such as steel. 材料的隔热性能 thermal insulation performance
6.1.3. Fire resistance of building materialsFireresistanceofthematerials口材料在高温下的物理力学性能Mechanical properties of materials athightemperature高温下或高温后，材料的力学性能随温度的升高而变化规律。当达到一定温度时，结构丧失承载力，构件失稳，或爆裂。The mechanical properties of material will change with the temperatureincrease.Whenthetemperaturereachesacertain value,thestructureloses its bearing capacity, the components is unstable and even burst.口材料的发烟性能Smokingpropertiesofmaterials一方面使人室息，另一方面遮挡视线而影响扑救和人员疏散The smoke can choke people, block the sight and hamper the rescueandevacuationofpeople口材料的毒性性能toxicityofmaterials材料热分解产生有毒物质随烟气扩散，将会产生更严重的危害The toxic produced by the thermal decomposition of materials diffuseswiththe smoke,whichwill causemore serious damage
6.1.3. Fire resistance of building materials Fire resistance of the materials 材料在高温下的物理力学性能 Mechanical properties of materials at high temperature 高温下或高温后，材料的力学性能随温度的升高而变化规律。当达到一 定温度时，结构丧失承载力，构件失稳，或爆裂。 The mechanical properties of material will change with the temperature increase. When the temperature reaches a certain value, the structure loses its bearing capacity, the components is unstable and even burst. 材料的发烟性能 Smoking properties of materials 一方面使人窒息，另一方面遮挡视线而影响扑救和人员疏散 The smoke can choke people, block the sight and hamper the rescue and evacuation of people 材料的毒性性能 toxicity of materials 材料热分解产生有毒物质随烟气扩散，将会产生更严重的危害 The toxic produced by the thermal decomposition of materials diffuses with the smoke, which will cause more serious damage
6.1.4.建筑火灾对结构的破坏Damage of buildingfire structures火对结构的损伤Damageoffiretostructure口建筑火灾对结构的破坏Damageofbuildingfiretostructuretimberstructure:结构本身发生燃烧并不断削弱结构构件的截面，势必造成结构倒塌The burning of structure will continuously weaken the cross-section of structural components, which definitely leads to thecollapseofstructureReinforcedConcreteStructureandSteelStructures材料本身并不燃烧，强度和弹性模量降低，造成截面破坏或变形较大而失效、倒塌The material itself is not-burning. But the decrease of strength andelastic modulus will cause the failure and collapse ofthe crosssectionorlargerdeformation
6.1.4.建筑火灾对结构的破坏 Damage of building fire structures 火对结构的损伤 Damage of fire to structure 建筑火灾对结构的破坏 Damage of building fire to structure timber structure: 结构本身发生燃烧并不断削弱结构构件的截面，势必造成结构倒塌 The burning of structure will continuously weaken the cross -section of structural components, which definitely leads to the collapse of structure Reinforced Concrete Structure and Steel Structures: 材料本身并不燃烧, 强度和弹性模量降低，造成截面破坏或变形较 大而失效、倒塌 The material itself is not-burning. But the decrease of strength and elastic modulus will cause the failure and collapse of the cross section or larger deformation