Sandwich In Eps Thermal Insulation Material Fire Combustion Characteristic Multiscale Research

As a kind of organic insulation material, expanded polystyrene(EPS) has a potential fire hazard. This paper has studied the combustion behavior of EPS within the sandwich.First, the process, kinetics and products of the pyrolysis of EPS at three kinds of atmosphere have been studied by using of TG-DSC-IR-MS.The experimental results have shown that EPS completely decomposed in all three kinds of atmosphere. In nitrogen, the pyrolysis of EPS could be well simulated by one first order reaction which has an activation energy of about150kJ/mol. The main pyrolysis products of EPS are C, H2O, CO, CO2, CH3CH2OH, acids, styrene, m-substituted benzene and some hydrocarbons. In air, EPS could be well simulated by one second order reaction which has an activation energy of about50kJ/mol. The main pyrolysis products are C, CO2, C4H3, C4H4, CH3CH2OH, alkynes and carbonyls. The pyrolysis of EPS could be well simulated by one second order reaction which has an activation energy of about110kJ/mol in oxygen. The main pyrolysis products are C, H2O, CO2, CH3CH2OH, aldehydes and some hydrocarbons.Secondly, the cone calorimeter is applied to study the combustion behavior of EPS at different heat radiation fluxes. The results show that ignition time shortens, the mean mass loss rate increases, the heat release rate increase and the hazard of EPS in fire increases with external radiation heat flux increasing. The calculative results of thermally thick kindling model are as follow:the critical heat flux is11.4kW/m2, the ignition temperature is346℃and the thermal properties parameter kpc is0.652. The combustion characteristic index for EPS insulation materials has been given when the heat flux is50kW/m2. The correlation between the ignition temperature caculated by the cone calorimeter and the pyrolysis temperature measured by the thermal gravimetric analyzer is explored, as well as the the correlation between the quality loss measured by the cone calorimeter and the quality loss measured by the TG.Finally, the combustion behavior of EPS within the sandwich has been studied by a experimental platform to simulate the sandwich fire. The results show the sustained combustion of EPS depends on whether the pool fire could be formed. The ignition methods, material thicknesses and sizes have a great influence on the combustion behavior of EPS. With the thickness and size of EPS increasing, the combustion is more sufficient which means more dangerous in fire.This paper studies the combustion of EPS, which could provide experimental and theoretical basis for the personnel evacuation, the rescue in high building fires, the fire protection design for the exterior insulation system of high buildings and the relative specification of fire protection design of high buildings.