British BS476-20 Fire Resistance Test

Judgment Content:

Integrity:

Under standard fire resistance test conditions, the ability of a building separation component to prevent flame and hot gas penetration or the appearance of flames on the unexposed side for a certain period when one side is exposed to fire. For example, when testing a wall, observations are made to determine whether cracks, holes, or other conditions occur that could allow flames and hot gases to spread from one side to the other. If the component does not exhibit flame penetration within the specified test duration (e.g., 30 minutes, 60 minutes, or longer), its integrity is considered compliant.

For opening components such as doors and windows, integrity testing is particularly important. The effectiveness of sealing materials in doors or windows under high fire temperatures in preventing the entry of flames and smoke is a critical evaluation factor.

Thermal Insulation:

Under standard fire resistance test conditions, the ability of a building separation component to maintain the temperature on its unexposed side below a specified limit for a certain period when one side is exposed to fire. Temperature monitoring devices such as thermocouples are typically used to measure temperature changes.

For instance, if thermal insulation is poor, high temperatures from the fire-exposed side can quickly transfer to the other side, potentially igniting items on that side or making it unsafe for people to approach the wall for evacuation. Standards specify that the temperature rise on the unexposed side must not exceed certain limits within a given time to ensure thermal insulation performance.

Load-Bearing Capacity:

This primarily applies to components that bear structural loads in buildings, such as beams, columns, and floors. Under high fire temperatures, the material properties of these components change, affecting their load-bearing capacity.

During testing, the component's actual load-bearing conditions in a building are simulated while exposing it to high fire temperatures. Parameters such as deformation and deflection under high temperatures are measured, and mechanical theories are applied to assess whether the load-bearing capacity meets requirements within the specified time. For example, a beam supporting the weight of a floor must be ensured not to collapse due to reduced strength under high temperatures within a designated period (e.g., 1–3 hours or other grades).

Applicable Product Scope:

(一)Partition Walls, Dividers, and Wall Panels: Non-load-bearing wall structures used to divide internal building spaces. These products require certain fire resistance properties to prevent fire spread between different areas.

(二)Door and Window Products:

Fully Insulated Doors and Windows: Capable of effectively blocking heat and flame propagation during a fire while maintaining structural integrity and thermal insulation.

Partially Insulated Doors and Windows: These offer relatively weaker thermal insulation but must still meet certain fire resistance requirements to ensure safe evacuation and overall building fire performance.

Non-Insulated Doors and Windows: While lacking thermal insulation功能, they must meet corresponding fire resistance standards to ensure functionality for a period during a fire, such as for evacuation purposes.

(三)Ceilings and Suspended Ceilings: As decorative and structural components of building interiors, ceilings and suspended ceilings must withstand certain levels of heat and flame impact during a fire. Therefore, fire resistance testing is necessary to ensure their safety.

(四)Glass Components: Glass products such as glass curtain walls and glass partitions are widely used in buildings. These glass components must also meet the fire resistance requirements of 476-20 to ensure they do not break or collapse during a fire, posing risks to personnel.

Steel Structures: Some steel structural components play critical roles in supporting building structures. Specially treated steel structures or those protected with fire-resistant coatings can undergo fire resistance testing according to 476-20 to verify their performance under fire conditions.