Mass and size distribution of firebrands generated from burning Korean pine (Pinus koraiensis) trees

Abstract

SUMMARYThe present study reports on a series of real-scale fire experiments that were performed to determine the mass and size distribution of firebrands generated from Korean Pine (Pinus koraiensis), a common conifer species indigenous to China, Japan, and Korea. The experiments were performed at the Building Research Institute in Tsukuba, Japan. The total tree height was fixed at 4.0 m and tree moisture content was varied to examine the influence that this parameter has on the mass and size distribution of the firebrands that are produced, under ambient wind conditions. The firebrands were collected using an array of pans. The pans used for firebrand collection were filled with water. This ensured that firebrands would be quenched as soon as they made contact with the pans. The firebrands were subsequently dried and the mass and size of more than 500 firebrands were measured. The Korean pine trees were also mounted on load cells during burning to determine the temporally resolved mass loss profiles. The mass loss data were used to compare the total amount of mass collected as firebrands with the total amount of mass burned. Results of this study are presented and compared with the mass and size distribution of firebrands collected from burning Douglas-fir trees, a conifer tree species indigenous to the U.S.A.

Exposing Decking Assemblies to Continuous Wind-Driven Firebrand Showers

“…For all tests, Douglas-fir wood pieces machined to dimensions of 7.9 mm (H) by 7.9 mm (W) by 12.7 mm (L) were used to produce firebrands. The same-size wood pieces were used to feed the bench-scale continuous Firebrand Generator in past studies and have been shown to be commensurate with sizes measured from full-scale burning trees, as well size distributions obtained from actual WUI fires [22,28].…”

“…Interestingly, post-fire damage studies have suggested for some time that firebrands are a significant cause of structure ignition in WUI fires, yet for over 40 years, firebrand studies have focused on understanding how far firebrands fly, known as spotting distance [10][11][12][13][14][15][16][17][18][19][20]. Few studies have examined firebrand generation [21][22][23] and the ultimate ignition of materials by firebrands [24][25][26][27]. For these reasons, the prior firebrand studies are of limited help in designing firebrand-resistant structures.…”

The Performance of Concrete Tile and Terracotta Tile Roofing Assemblies Exposed to Wind-Driven Firebrand Showers

“…Manzello et al [5] have shown that the firebrands produced using these filtering and ignition procedures generate firebrands with mass up to 0.2 g and surface area up to 1000 mm 2 . This is within the range of firebrands generated from burning conifer species (Douglas-Fir and Korean Pine Trees) [8][9].…”

On the Development and Characterization of a Reduced Scale Continuous Feed Firebrand Generator

“…While firebrands have been studied for some time, most of these studies have been focused on how far firebrands fly [4][5][6][7][8][9][10][11][12][13][14]. Unfortunately, very few studies have been performed regarding firebrand generation [15][16][17] and the ultimate ignition of materials by firebrands [18][19][20][21].…”

“…Recently Manzello et al [17,[22][23][24][25] developed an experimental apparatus, known as the NIST Firebrand Generator (NIST Dragon), to investigate ignition vulnerabilities of structures to firebrand showers. The NIST Firebrand Generator is able to generate a controlled and repeatable size and mass distribution of glowing firebrands.…”