Measurement of Heat Transfer and Fire Damage Patterns on Walls for Fire Model Validation

• NCJ Number: 310170
• Author(s): Matthew J. Didomizio; Jonathan W. Butta
• Date Published: September 2024
• Length: 286 pages
• Grant Number(s): 15PNIJ-21-GG-04167-RESS
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)

Annotation

This technical report addresses the measurement of heat transfer and fire damage patterns on walls for fire model validation.

Abstract

This report details the measurements and findings from a series of experiments addressing three validation spaces: thermal exposure to walls, heat transfer within walls, and fire damage patterns on walls. The study revealed that the cumulative heat flux over the surface of a fire-exposed GWB wall was not consistent with the observed discoloration and mass loss fire effects. On the other hand, a distinct relationship was found between mass loss and discoloration fire effects, and it was determined that lines of demarcation between charred and un-charred regions of the fire-exposed wall coincided with a mass loss ratio of 14.9 ±2.1% for the GWB considered. This study revealed a pathway for fire investigators to relate fire model predictions (mass loss occurring in a GWB wall, driven by thermal decomposition of the material) to physical evidence collected in an investigation (discoloration fire damage patterns). A total of 63 experiments were conducted, encompassing seven fire sources and three wall types. Fire sources include a natural gas burner, gasoline and heptane pools, wood cribs, and upholstered furniture. Three types of walls were used to address the three validation spaces: a calcium silicate board (CSB) wall to address the heat transfer through walls validation objective; a gypsum wallboard (GWB) wall to address the fire damage patterns validation objective; and a steel wall (in the form of a plate heat flux sensor of equivalent area to the CSB and GWB walls) to address the heat transfer to walls validation objective.