Evaluation on Combustion Characteristics of Finishing Materials for Exterior Walls

Existing fire test methods reply on measurement of the energy released rate to identify the combustion properties of a material. However, they are inadequate when assessing combustion characteristics of a composite material characterized by vertical flame spread and different inside/outside combustion behaviors. In addition, major factors that affect the flame spread outside the building include the combustion characteristics of materials used as well as air flow around a skyscraper. However, since it is highly difficult to analyze and forecast the air flow from a fire engineering viewpoint, an investigation of the flame spread characteristics of exterior walls of a building depends primarily on the combustion characteristics of materials. Hence, this study examined, using ISO 13785-2 testing method, the temperature changes and vertical flame spread behaviors of one of the finishing materials for exterior walls--（generic ＆ fire-resistant） aluminium panels by a real-scale combustion experiment. According to the results of real-scale experiment, the maximum heat temperature of 987.7 ℃ was recorded seven minutes after the fire test was initiated while the fire-resistant aluminium panels showed the maximum heat temperature of 850.2℃ after exposed for approximately 12 min. The vertical flame spread properties put more emphasis on the time required to reach the maximum temperature rather than its magnitude and there was a five minutes difference between the materials.

Modeling of wind-driven rain absorption ratio of building exterior finishing materials based on field measurements

Wind-driven rain(WDR)constitutes a significant source of moisture for building facades,which poses considerable challenges to both the thermal insulation performance and long-term durability of walls.Prior studies have contributed significantly to the understanding of fluid behavior and moisture response of WDR upon impacting walls.However,the quantification of absorbed rainwater by the wall remains elusive.To address this gap,this study focuses on comprehending the dynamic WDR absorption behavior of various exterior finishing materials.Specifically,nine types of finishing materials were selected as research objects and conducted field measurements.The findings reveal that WDR absorption ratio is influenced by physical parameters of materials,surface waterproofing and the cumulative WDR.Leveraging multiple regression fittings,we established an empirical WDR absorption ratio calculation mode.This model serves as a valuable reference for determining building simulation parameters regarding dynamic moisture boundary conditions on the exterior surfaces of walls.By providing empirical insights into WDR absorption,our research contributes to a more comprehensive understanding of moisture behavior in building envelopes,thereby aiding in the development of effective strategies for enhancing building performance and durability.