Influence of Traditional Plaster Layer on the Combustion Performance of Larch and Korean Pine Wood

This study investigated the effects of traditional plastering on the combustion behavior of timber used in historic structures. Larch and Korean pine specimens treated with the traditional one hemp fibre and five plaster layer technique were tested using a Fire Propagation Apparatus (FPA). The plaster layer shortened the time to ignition and promoted fire propagation during the early combustion stage, while markedly reducing the peak heat release rate and toxic gas production and increasing the char yield of the wood specimens. These findings clarify the dual effect of traditional plastering on timber combustion and provide experimental evidence for assessing the fire performance of traditionally plastered components in historic timber buildings.

PRELIMINARY STUDY OF DEPENDENCE OF SMOKE AND CARBON MONOXIDE EMISSION ON HEAT RELEASE RATE FROM FAST-GROWING WOOD SPECIES

The aim of this paper is to create the model for prediction of carbon monoxide release rate (CORR) and smoke production rate (SPR) from heat release rate (HRR) of fast-growing wood species. The model is independent on wood species, thus is suitable for all fast-growing wood species. Three wood species hybrid poplar J-105 (Populus nigra × P. maximowiczii A. Henry), white willow (Salix alba L.) and black locust (Robinia pseudoacacia L.) were used for universal model creation. The heat release rate, smoke production rate and carbon monoxide release rate have been measured at three heat fluxes (25, 35 and 50 kW.m-2) by the cone calorimeter. The average values of CORR and SPR for all investigated wood species were 0.051 g.m-2.s-1 and 0.086 m2.m-2.s-1, respectively. Both dependencies of SPR and CORR on HRR have shown similar trends during the ignition phase (unstable trend) and during the intense burning phase (roughly linear increasing with HRR). The main difference was shown during the steady state phase (dependency of SPR on HRR is stable while dependency of CO on HRR is highly unstable). The results also proved a significant impact of wood density on these dependencies, thus, the neural network for prediction of SPR, CORR from HRR was applied. The coefficients of determination R2 for trained neural networks, for both SPR and CORR, were achieved in the range from 0.96 to 0.97

Characterization of the Burning of Oriented Strand Boards Exposed to Flame

Since the methods based on the interaction of a relatively low intensity flame on the lignocellulose sample surface often do not allow measuring the heat release rate (HRR), a procedure using oxygen consumption calorimetry was proposed. The method was applied to OSB samples with dimensions of 320 mm x 140 mm x 25 mm placed in a vertical position. During the measurement, in addition to the HRR, the production of smoke, which was significant after stopping the burner, was also monitored. The average net value of HRR at burner outputs of 3 kW, 4 kW and 5 kW was 2.339 kW and the smoke specific extinction area was in the range of 10.88 m2.kg-1 and 13.19 m2.kg-1.