A Study on Smoke Hazards from Burning Aramid Fibre Composite Materials in a Building Fire

Description

Aramid fibre composite material (AFCM) has emerged as a popular material for bothrepairing old buildings and constructing new buildings. However, the polymer matrixmaterials, adhesives and aramid fibres are combustible. Consequently, more smoke isemitted by burning AFCM than by burning composite materials based on carbon or glassfibres. When buildings made of AFCM catch fire, the emitted smoke generates anenvironment that is hazardous for the occupants and firefighting personnel. In addition,it has been reported that several laboratory personnel who frequently carry out standardfire safety tests on AFCM have suffered from smoke exposure.This project will study the smoke hazards associated with burning AFCM products inbuilding fires. The burning behaviour and smoke hazards of AFCM products (in theform of both panes and sheets, which are commonly used in buildings) will beinvestigated using bench-scale, medium-scale and full-scale experiments. During theearly stages of a room fire, the upper part of vertically orientated AFCM products areexposed to a layer of hot gas and they can easily ignite and emit smoke. Therefore, thefire behaviour of vertically orientated AFCM products under non-uniform high radiativeheat fluxes will be investigated using a cone calorimeter. Multiple radiative heat fluxeswill be tested on both vertically and horizontally orientated AFCM samples in the conecalorimeter. The surface temperatures, ignition times and fire and smoke potencyparameters of the AFCM samples will be measured. The concentrations of toxic gaseswill be measured using Fourier transform infrared (FTIR) spectrometry. Theseconcentration values will be used in an N-gas model to assess the smoke toxicity emittedfrom burning AFCM samples (and the model will also be modified to explore the effectsof taking into account different types of gas, for example, taking into account onlycarbon monoxide). Medium-scale experiments will be carried out on the AFCM samplesusing a thermal radiator that can emit higher radiative heat fluxes at the top comparedto the bottom. The smoke emission resulting from changes in the thermal decompositionat various AFCM surface temperatures will be observed. Full-scale burning tests on partof a model AFCM system in a building will be carried out to investigate the toxicity ofthe emitted smoke and the reduced visibility. The results will then be used to proposeappropriate fire safety tests for assessing the smoke hazards of AFCM.?