Evaluation of the Fire Impact of Cellulose-Based Indoor Building Finishing Materials According to Changes in Room Size Aspect Ratio

Abstract

In modern society, the size of buildings tends to expand due to technological advances. However, while prioritizing performance design and specific building materials, fire research has fallen short of creating a comprehensive fire characteristic database for building materials. This study presents a plan for building a big data resource to evaluate the fire performance of cellulose-based flame retardant building finishing material in buildings of varying sizes. The three types of building finishing materials applied in this study are polyurethane foam, MDF, and cellulose-based building finishing materials. The variables were determined based on the floor area, and the change in floor area was calculated using the aspect ratio, a dimensionless number. Data analysis utilized the Fire Dynamics Simulator (FDS) to determine the time required to meet life safety standards for temperature, visibility, and Fractional Effective Dose (FED). The results confirm a correlation between the safe evacuation time (ASET) and increasing floor area. Additionally, the study demonstrates that cellulose-based flame-retardant building finishing material effectively maintains safe evacuation times even with increasing floor areas, as evidenced by increases of 41.0 s, 13.2 s, and 97.5 s in temperature, visibility, and FED, respectively.

1. Introduction

The worldwide average number of fire accidents was 2.4 million annually from 1993 to 2020, leading to approximately 40,000 deaths [1]. Moreover, in 2021, fire-related fatalities averaged 1.3 deaths and 4.9 injuries per 100,000 people, with building fires comprising around 31.3% of all fires [1].

Modern society is showing rapid growth in the construction industry due to the development of technology, and buildings are gradually expanding in size, as seen by the increase in enlargements and high-rise buildings, due to overcrowding populations [2,3]. However, this trend is accompanied by a gradual rise in fire accidents within buildings, leading to numerous deaths and significant property damage each year. As a result, interest in fire safety management in buildings is growing [4]. Therefore, a fire safety evaluation must be conducted in the construction planning stage to mitigate fire risk, which necessitates specialized expertise for accurate assessments [5].

In 2022, a fire at an apartment in Bronx, New York, USA, resulted in 17 deaths and 44 injuries due to smoke inhalation [6]. Smoke generated by the combustion of combustible substances during building fires is highly toxic, containing soot particles and steam, and it severely impairs occupants’ visibility, which is a primary cause of casualties [7,8]. Notably, building finishes composed of chemicals release a significant amount of harmful substances during combustion [8].

In addition, heat spreading through building finishing materials contributes to the growth of fires, making it imperative to scrutinize the progression of indoor building fires regarding temperature elevation over time. This can be achieved by employing HRR (heat release rate) and THR (total heat release) values [9,10].

In a previous study focused on fire prevention in buildings, Cui et al. introduced a knowledge graph aimed at visualizing the causes of fire, the fire development process, and the evacuation procedures based on building fire case information in China [11].

Zhang et al. addressed the limitations of the indicator system method currently employed in evaluating the fire risk of high-rise buildings. They proposed a new method for analyzing the probability of fire occurrence, which integrates the spatial Markov chain model [12].

Dong et al. investigated the temporal distribution and flow of smoke in buildings with complex structures using two software tools, Pyrosim and Revit [13].

Zhang et al. emphasized the significance of evacuation routes by investigating the utilization of large-scale crowd evacuation routes using the hierarchical node relocation model (HNRM), taking into account the intricacies of the fire evacuation process within complex structures [14].

Kodur et al. discussed the adverse effects of fire hazards in buildings and the constraints of current fire safety measures. Additionally, they underscored the importance of developing fire suppression systems, adopting fire design approaches, characterizing building materials, and implementing performance-based codes as methods to enhance fire safety [15].

Kim et al. conducted a fire hazard assessment for various building finishing materials in medical facilities using FDS and Pathfinder simulations. Their findings suggested the potential use of cellulose-based construction finishing materials and proposed measures to evaluate the safety of occupants during evacuation [16].

Ahn et al. conducted a study on construction finishing materials, where they experimented with manufacturing fire-resistant finishing materials by incorporating expandable graphite and magnesium hydroxide into cellulose-based construction finishing materials. As a result of the experiment, findings suggested the potential for eco-friendly construction finishing materials through the recycling of waste paper and highlighted the impact of particle size of expandable graphite on flame-retardant performance [17].

Han proposed the necessity of legal regulations concerning the fire vulnerability and flame-retardant performance of recently interior finishing materials. This proposal was based on fire combustion tests, flame propagation tests, and smoke density tests conducted on polyethylene combustible synthetic resin insulated wallpaper, commonly used for insulation and interior effects [18].

Kang et al. conducted a physical test on the vertical fire diffusion of outer wall finishing materials, combining the flame-retardant properties of polyurethane boards—commonly used as insulation materials in Asia—with aluminum sheets or granite materials, and evaluated the extent of fire diffusion resulting from this combination [19].

Park et al. conducted experiments following the test regulations of IMO Res to assess the combustibility and emission of combustion gases from flame-retardant plywood. As a result of the experiment, they suggest the potential of flame-retardant plywood as a building finishing material, achievable through enhancements in the surface functionality of wood [20].

Previous fire research has primarily focused on fire analysis techniques, fire risk factors, enhancements of evacuation routes, and improving overall fire safety. Also, research on building finishing materials has centered on developing new materials, emphasizing the importance of flame-retardant properties, and evaluating their impact on fire spread.

However, the structure of buildings is diversifying rapidly, yet the fire characteristics of new building finishing materials are not being integrated into a database. In addition, the current performance-based design should incorporate the fire characteristics of building finishing materials to mitigate fire risks like malfunctioning firefighting equipment. To address these concerns, this study aimed to identify the diversifying building structures and fire characteristics of building finishing materials and propose a research plan for constructing big data.

To understand how building structure influences fire characteristics, this study employed simulations to examine the effect of various building finishing materials on the internal space. Additionally, we selected the aspect ratio of floor area as the key variable to develop a strategy for utilizing basic data related to size variations. The variable chosen for building size was the aspect ratio of the floor area. Computational fluid dynamics (CFD) analysis was conducted using a Fire Dynamics Simulator (FDS) to assess fire characteristics. Parameters such as Fractional Effective Dose (FED), temperature, and visibility were selected for the analysis, and a quantitative evaluation was performed.

2. Experimental and Methods

2.1. Experimental Conditions

In modern society, buildings come in various shapes, but square shapes are common. This study aims to examine the fire characteristics of building finishing materials as the size of the building increases. The variable used to measure the building size is the floor area, with the aspect ratio of width to length (W:L) increasing from 1:1 to 1:5. However, to simulate harsh conditions, the indoor space was fixed at a low ceiling height of 2.2 m. Figure 1 illustrates the aspect ratios used in this study, while

Table 1. Fire room size.

Properties	W (m)	L (m)	H (m)
Aspect ratio 1	2	2	2.2
Aspect ratio 2		4
Aspect ratio 3		6
Aspect ratio 4		8
Aspect ratio 5		10

outlines the actual sizes used for modeling.

2.2. Fire Analysis

2.2.1. Fire Modeling

In this study, the ignition source was a 0.2 m × 0.2 m × 0.2 m wooden block, and the simulation confirmed flame spread with the building finishing materials attached to the wall. Additionally, the fire room was configured as a closed space with no external air inflow. Polyurethane foam and MDF are commonly used building materials in Asia (including Korea) contributing to the high fire risk. To address this concern, we selected three different building finishing materials to highlight the importance of using flame-resistant materials and the need to evaluate the fire performance of newly developed building finishing materials. The building finishing materials selected for this study included polyurethane foam, MDF, and cellulose-based flame-resistant finishing materials [17,21]. The cellulose-based flame-retardant building finishing material (CFBFM) comprises 100 g of cellulose, 30 g of expanded graphite, and 20 g of magnesium hydroxide. Figure 2 depicts the flowchart of specimen production.

The specimen was manufactured with dimensions of 10 cm × 10 cm × 2 cm, conforming to the ISO 5660-1 standard [22] to confirm the flame-retardant performance. The manufacturing procedure was carried out by mixing water, expanded graphite, and magnesium hydroxide with finely pulverized waste paper, 3D printing it [23], and drying it.

The physical property values of MDF and CFRBFM were measured through a cone calorimeter (FESTEC Co., Seoul, Republic of Korea) and LFA 1000 (LINSEIS, Selb, Germany) experiments. Data values provided by FDS were used for the polyurethane foam.

Table 2. Reaction parameter.

Properties	Polyurethane Foam	MDF	CFRBFM
Density (kg/m3)	40.0	536.1	530.0
Specific heat (kJ/kg·K)	1.0	1.8	4.122
Conductivity (W/m·K)	0.05	0.2	0.835
Heat of combustion (kJ/kg)	30,000.0	19,702.5	1246.7
CO yield (kg/kg)	0.0310	0.0668	0.0284
Soot yield (kg/kg)	0.10	0.009515	0.009861

outlines the reaction parameters of the building finishing materials, while

Table 3. Boundary condition for fire simulation.

Properties	Condition
Heat Release Rate (HRR)	200 kW
Air Temperature	20 °C
Simulation Time	400 s
Interior Finishing Material Thickness	2 cm

specifies the boundary conditions.

2.2.2. Mesh Resolution

The calculation accuracy strongly depends on the FDS mesh size. The size of the analysis grid can be determined by the characteristic fire diameter using Equation (1) in the fire plume analysis:

$${\mathrm{D}}^{\mathrm{*}}={\left(\frac{\dot{\mathrm{Q}}}{{\mathsf{\rho }}_{\mathrm{\infty }}{\mathrm{C}}_{\mathrm{p}}{\mathrm{T}}_{\mathrm{\infty }}\sqrt{\mathrm{g}}}\right)}^{2/5}$$

(1)

where ${\mathrm{D}}^{\mathrm{*}}$: characteristic fire diameter, $\dot{\mathrm{Q}}$: total heat release rate (kW), ${\mathsf{\rho }}_{\mathrm{\infty }}$: outside air density (kg/m³), ${\mathrm{C}}_{\mathrm{p}}$: specific heat (kJ/kg·K), ${\mathrm{T}}_{\mathrm{\infty }}$: outside air temperature (K), $\mathrm{g}$: acceleration of gravity (m/s²), and ${\mathsf{\delta }}_{\mathsf{\chi }}$: nominal size of a mesh cell.

The ${\mathrm{D}}^{\mathrm{*}}/{\mathsf{\delta }}_{\mathsf{\chi }}$ parameter is only valid if the value is between 4 and 16 [24]. The ${\mathrm{D}}^{\mathrm{*}}$ applied to this analysis is 0.503 m, and in this paper, ${\mathrm{D}}^{\mathrm{*}}/{\mathsf{\delta }}_{\mathsf{\chi }}$ has a value of 10.06.

2.2.3. Safety Criteria

The life safety criteria in performance-based design are defined by parameters such as temperature, visibility, oxygen (O₂), carbon monoxide (CO), and carbon dioxide (CO₂), measured at a height of 1.8 m above the floor, which corresponds to the respiratory threshold for evacuees [25]. Temperature affects residents by causing thermal effects, and high temperatures of 60 °C or higher increase the risk of respiratory issues and skin burns [26,27]. Visibility is a factor that can obstruct evacuation due to the blocking of occupants’ view. Therefore, it is defined as safe when visibility is secured at more than 5 m [28]. Additionally, O₂, CO, and CO₂ values can be calculated using the Fractional Effective Dose (FED), which assesses the behavioral impact of gas concentration in the respiratory zone of the occupant. Equations (2)–(5) depict the calculation methods for FED [29].

$${\mathrm{F}\mathrm{E}\mathrm{D}}_{\mathrm{t}\mathrm{o}\mathrm{t}}={\mathrm{F}\mathrm{E}\mathrm{D}}_{\mathrm{C}\mathrm{O}}\times {\mathrm{H}\mathrm{V}}_{{\mathrm{C}\mathrm{O}}_2}+{\mathrm{F}\mathrm{E}\mathrm{D}}_{{\mathrm{O}}_2}$$

(2)

$${\mathrm{F}\mathrm{E}\mathrm{D}}_{\mathrm{C}\mathrm{O}}=4.607\times {10}^{-7}{\left({\mathrm{C}}_{\mathrm{C}\mathrm{O}}\right)}^{1.036}\mathrm{t}$$

(3)

$${\mathrm{F}\mathrm{E}\mathrm{D}}_{{\mathrm{O}}_2}=\frac{\mathrm{t}}{60\mathrm{e}\mathrm{x}\mathrm{p}\left[8.13-0.54\left(20.9-{\mathrm{C}}_{{\mathrm{O}}_2}\right)\right]}$$

(4)

$${\mathrm{H}\mathrm{V}}_{{\mathrm{C}\mathrm{O}}_2}=\frac{\mathrm{e}\mathrm{x}\mathrm{p}\left(0.1930{\mathrm{C}}_{{\mathrm{C}\mathrm{O}}_2}+2.0004\right)}{7.1}$$

(5)

where, t: unit time(s), ${\mathrm{C}}_{\mathrm{C}\mathrm{O}}$: CO concentration (ppm), ${\mathrm{C}}_{{\mathrm{O}}_2}$: O₂ concentration (%), and ${\mathrm{C}}_{{\mathrm{C}\mathrm{O}}_2}$: CO₂ concentration (%).

The FED value serves as a criterion for assessing the impact of harmful gases resulting from combustion on the human body. An FED value of 1 indicates fatality for 50% of the occupants. Additionally, an FED value of 0.3 is considered an index of human body incapacitation [30,31].

In this study, the measurement criteria for fire risk assessment were divided into three categories: temperature, visibility, and FED.

Table 4. Performance criteria for life safety [25,30].

Properties	Limit
Respiratory limit line	1.8 m
Fractional Effective Dose (FED)	<0.3
Temperature	<60 °C
Visibility	>5 m

outlines the life safety criteria utilized in this study.

3. Results

3.1. Analysis Result

Analysis Result of Safety Criteria

In this study, the measurement locations for life safety criteria were chosen as the farthest points from the ignition source, based on the height of 1.8 m from the floor, representing the breathing area.

Table 5. Fire room measurement point by aspect ratio.

Properties	W, L, H (m)
	Fire Source	Measurement Point
Aspect ratio 1	0.1, 0.1, 0.2	1.9, 1.9, 1.8
Aspect ratio 2		1.9, 3.9, 1.8
Aspect ratio 3		1.9, 5.9, 1.8
Aspect ratio 4		1.9, 7.9, 1.8
Aspect ratio 5		1.9, 9.9, 1.8

details the location of each measurement point based on aspect ratios.

The arrival time of the life safety criteria can be defined as ASET (available safety egress time), and the measurement results showed that the ASET varied depending on the building finishing material. Figure 3 illustrates the variation in the ASET for each building finishing material according to the aspect ratio, while

Table 6. ASET for each building finishing material by aspect ratio change.

Properties		Aspect ratio
		1	2	3	4	5
Polyurethane foam	Temperature	3.20 s	4.80 s	6.00 s	7.60 s	9.21 s
	Visibility	3.20 s	4.80 s	6.00 s	7.60 s	9.21 s
	FED	8.40 s	8.80 s	10.40 s	11.61 s	12.80 s
MDF	Temperature	3.20 s	4.80 s	6.40 s	8.40 s	10.80 s
	Visibility	3.20 s	4.80 s	6.40 s	8.40 s	11.20 s
	FED	14.40 s	16.41 s	18.81 s	21.21 s	22.81 s
CFRBFM	Temperature	3.60 s	5.20 s	7.20 s	9.61 s	11.61 s
	Visibility	4.00 s	5.20 s	7.20 s	10.00 s	11.61 s
	FED	68.81 s	101.22 s	135.64 s	159.62 s	186.45 s

presents the ASET values for each building finishing material.

The simulation results confirmed that the ASET was delayed as the aspect ratio increased. With the aspect ratio increasing from 1 to 5, the arrival times of temperature, visibility, and FED safety criteria for polyurethane foam were delayed by 6.0 s, 6.0 s, and 4.4 s, respectively. For MDF, similar delays were observed: 7.6 s for temperature, 8.0 s for visibility, and 8.4 s for FED criteria. CFRPBM exhibited the most significant delays with increasing aspect ratio. The reference excess times for temperature and visibility increased by 8.0 and 7.6 s, respectively. However, the FED excess time saw a much larger delay of 117.6 s.

The average increase in the ASET for temperature, visibility, and FED with the increase in aspect ratio was 1.5 s, 1.5 s, and 1.1 s, respectively, for polyurethane foam and 1.9 s, 2.0 s, and 2.1 s for MDF. CFRBFM exhibited an average increase of 2.0 s, 1.9 s, and 29.41 s, respectively, indicating its superior performance in the FED category compared to the building finishing material of the control group.

3.2. Change in Floor Area with Same Aspect Ratio

To further analyze the impact of building finishing materials based on the area of the fire room, we assumed that only the area was expanded without changing the aspect ratio. The aspect ratio was fixed at 1, and the length was extended by 2 m per case for additional simulations. Figure 4 depicts the conditions for the simulation with a fixed aspect ratio, and

Table 7. Fire room size of same aspect ratio condition.

Properties	W (m)	L (m)	H (m)
Case 1	2	2	2.2
Case 2	4	4
Case 3	6	6
Case 4	8	8
Case 5	10	10

details the sizes applied to the simulation.

In same aspect ratio conditions, the change in area results in a significant increase compared to conditions where the aspect ratio changes. This is due to the smoke’s radial expansion driven by heat buoyancy, which significantly impacts arrival times. Figure 5 illustrates the variation in the arrival time of safety standards for different building finishing materials under fixed aspect ratio conditions, while

Table 8. ASET for each building finishing material under same aspect ratio conditions.

Properties		Case
		1	2	3	4	5
Polyurethane foam	Temperature	3.20 s	6.00 s	8.80 s	11.20 s	13.21 s
	Visibility	3.20 s	6.00 s	8.80 s	11.20 s	13.61 s
	FED	8.40 s	12.40 s	16.00 s	22.81 s	28.82 s
MDF	Temperature	3.20 s	6.00 s	10.40 s	17.61 s	24.42 s
	Visibility	3.20 s	8.40 s	12.40 s	17.61 s	23.61 s
	FED	14.40 s	22.01 s	27.61 s	36.03 s	41.65 s
CFRBFM	Temperature	3.60 s	7.20 s	11.61 s	41.22 s	167.62 s
	Visibility	4.00 s	7.20 s	17.21 s	36.81 s	56.81 s
	FED	68.81 s	156.02 s	250.81 s	351.25 s	>400.00 s

presents the ASET of building finishing materials for each case.

The simulation results showed varying ASET differences between temperature, visibility, and FED criteria in Cases 1 and 5. For polyurethane foam, these delays ranged from 10.0 s (temperature) to 10.4 s (visibility) and 20.4 s (FED). Similarly, MDF exhibited delays of 21.2 s (temperature), 20.4 s (visibility), and 27.2 s (FED). However, CFRBFM displayed a significantly larger disparity. The time differences for CFRBFM were 164.0 s (temperature), 52.8 s (visibility), and a substantial 331.2 s (FED). The average increase in the ASET for temperature, visibility, and FED with the increase in area was 2.5 s, 2.6 s, and 5.11 s, respectively, for polyurethane foam and 5.3 s, 5.1 s, and 6.8 s for MDF. In contrast, CFRBFM exhibited increases of 41.0 s, 13.2 s, and 82.8 s, respectively, demonstrating superior performance in temperature and FED compared to the building finishing material of the control group. These results indicate enhanced safety in indoor fire diffusion suppression and occupant breathing areas.

3.3. Distribution of ASET in Room Size Conditions

The ASET of the building finishing material tended to increase with the increase in the aspect ratio. However, it was confirmed that there was no significant difference between the ASET changes in polyurethane foam and MDF. On the other hand, while the ASET change for CFRBFM did not differ significantly in the temperature and visibility items, it was observed that the ASET increased significantly with the increase in the aspect ratio in the FED item.

Therefore, when CFRBFM is used as indoor finishing material, the correlation between excess time and the aspect ratio of temperature and visibility is represented by Equation (6), while the correlation between the FED and aspect ratio is represented by Equation (7).

$$y_{T,V}=0.10107x^2+1.41607x+2.163$$

(6)

$$y_{FED}=-1.54286x^2+38.62514x+31.444$$

(7)

Figure 6 illustrates the ASET distribution of CFRBFM based on life safety criteria.

An increase in the aspect ratio of the floor area results in a corridor-shaped structure. Therefore, we conducted an additional fire impact assessment of building finishing materials to account for changes in area while maintaining the same aspect ratio. With the aspect ratio being maintained at 1, an increase in the area corresponds to an increase in the square of the length.

As a result of the simulation, when CFRBFM is used as an indoor finishing material, the correlation between the ASET of temperature, visibility, and FED and the length of the floor area is shown in Equations (8)–(10), respectively. However, in Case 5, the ASET for FED was not measured during the simulation operation time and was excluded.

$$y_{Temperature}=4.83571x^2-39.92557x+73.032$$

(8)

$$y_{Visibility}=0.77125x^2-2.4935x+5.432$$

(9)

$$y_{FED}=0.82687x^2+38.83675x-12.2675$$

(10)

Applying Equation (10), the FED standard ASET for Case 5 is predicted to be 458.79 s. Figure 7 illustrates the distribution of the ASET for CFRBFM based on life safety criteria under the same aspect ratio condition.

In terms of temperature and visibility of CFRBFM, the ASET showed a similar distribution, but the difference in the ASET increased when a certain length was exceeded. Trend line analysis confirmed that the trend line of temperature and the trend line of visibility intersect at approximately 6.74 m. Therefore, it is judged that mixing Equations (9) and (10) based on a floor length of 6.74 m provides a more accurate correlation for CFRBFM’s ASET of the temperature criteria.

4. Discussion

Fire development in a compartment proceeds in the order of growth, full development, and decline. The risk of a flashover phenomenon occurs when the internal temperature rises above 600 °C during this process [32,33]. Therefore, the temperature change observed during the simulation can be used to predict the flashover phenomenon. Figure 8 presents the distribution of temperature changes over time for different building finishing materials.

The simulation analysis revealed that polyurethane foam exceeded 600 °C within 50 s and reached a maximum temperature of 1265 °C, regardless of compartment structure and size. In contrast, MDF reached a maximum of 978 °C, lower than polyurethane foam but still exceeding 600 °C within 100 s, posing a risk of a flashover phenomenon.

In contrast, CFRPBM exhibited a significantly lower maximum temperature of around 433 °C. In the largest compartment (Case 5), the maximum temperature only reached around 72 °C, highlighting the fire suppression effect due to its flame-retardant properties.

The results may vary depending on openings like doors or windows in the compartment, which can affect airflow. However, it is judged that securing data for building finishing materials can be a valuable tool for ensuring the safety of occupants.

5. Conclusions

In this study, a fire impact assessment was conducted on three types of building finishing materials (polyurethane foam, MDF, and CFRBFM) in response to changes in the indoor floor area. For the fire risk assessment, the ASET of life safety criteria in three items—temperature, visibility, and FED—was measured, and the following results were derived through an analysis of the measurement results.

(1)

When the aspect ratio increased by 1, the ASET for temperature and visibility rose by an average of 1.5 to 2.0 s for all three building finishing materials. However, the impact on the FED’s ASET varied considerably. Polyurethane foam and MDF saw average increases of 1.1 s and 2.1 s, respectively. In contrast, CFRBFM exhibited a substantial increase of 29.41 s, highlighting a significant difference in fire safety performance for larger compartments.

(2)

Increasing the area while maintaining the aspect ratio resulted in an average ASET increase of 2.5 s to 6.81 s for polyurethane foam and MDF. CFRBFM, however, exhibited a larger increase in the ASET, with average delays of 41.0 s, 13.2 s, and 82.8 s for temperature, visibility, and FED, respectively. This suggests that CFRBFM may offer an advantage in securing an ASET for temperature and FED in larger compartments.

(3)

Regardless of the type of increase in the floor area, both polyurethane foam and MDF exhibited a slight increase in the ASET within 8.5 s as the area expanded, with smoke spreading over the entire area within 42.0 s.

(4)

The ASET of CFRBFM showed different results depending on the shape of the floor area. When the floor area was increased proportionally by the aspect ratio, the increase in the ASET tended to be uniform. However, when the area increased with the same aspect ratio, it was observed that the increase in the ASET gradually rose. In particular, in the case of temperature, it was noted that the increase in the ASET escalated rapidly when the length of the floor surface exceeded 6 m. This was attributed to the flame-retardant performance of CFRBFM. Therefore, it was demonstrated that the larger the size of the room, the more effective it was in securing the ASET.

(5)

The fire risk assessment of building finishing materials was conducted by incrementally increasing the floor area in five stages based on the aspect ratio. As a result of the study, when the building finishing material is CFRBFM, the correlation between temperature, visibility, FED’s ASET, and changes in floor area conditions can be expressed by the trend equation provided in Equation (6) through (10).

(6)

By monitoring temperature changes over time, we observed a maximum internal temperature increase of 433 °C for CFRPBM within 400 s. This finding suggests a very low risk of flashover, indicating CFRPBM’s strong flame-retardant performance.

(7)

This study investigated the effectiveness and correlation between fire risk and cellulose-based building finishing materials by assessing fire risk while varying the building’s floor area based on its aspect ratio. This research method demonstrates the potential of big data analysis for evaluating fire risk, predicting fire characteristics and making ASET predictions based on the chosen building finishing materials.

However, further research is necessary to explore the combined impact of changes in both area and volume, including the fire space height and the reference length used for aspect ratio calculations. Additionally, comprehensive big data and ensuring the reliability of building finishing materials require further research and cross-validation using various up-to-date numerical models. Experimental data, including thermal pyrolysis data, are also considered essential for determining the chemical properties of building finishing materials.