Fire protection is a crucial safety requirement in the field of building design and construction. As a common building type, the fire resistance of steel structures has become one of the key concerns. The high temperatures caused by fire can have a direct impact on steel structures. Although steel itself is not flammable, its strength, stiffness, and stability will be significantly reduced under a high-temperature environment, and even the phenomenon of high-temperature softening will occur. Therefore, if too much heat is absorbed in a fire, the steel structure may lose its structural integrity, leading to the collapse of the building. To improve the fire performance of steel buildings, effective fire prevention techniques and measures are needed. These measures slow the heating of the steel. They also buy time for putting out fires and for evacuating people.
Table of Contents
Understanding Fire Risks in Steel Structures
High temperatures significantly affect steel structures. They are susceptible to oxidation and corrosion. These reduce properties like strength, stiffness, and toughness. This reduction in properties can lead to problems such as deformation, buckling, and twisting of the steel structure. Steel does not burn. But, under a high-temperature flame, its strength decreases as the temperature rises. When the temperature reaches an ultimate critical point, the load-carrying capacity of the steel is significantly reduced. In actual fires, the critical temperature at which the steel structure loses its static equilibrium stability is about 500℃, while the fire temperature usually reaches 800~1000℃.
Therefore, steel structure buildings must take fire prevention measures to prevent the steel structure from rapidly warming up to the critical temperature in a fire. This will not only gain valuable time for fire extinguishing and safe evacuation of people but also reduce the damage caused by the fire. Effective fire protection measures include the use of fire-resistant coatings, fire-resistant panels, and water sprinkler systems.
Fire Protection Methods for Steel Structures
| Method | Principle | Materials | Application Range |
|---|---|---|---|
| Spray Method | Using | Vario | Any stee |
| Encapsulation Method | Wrapping | Fireproof boards, concrete, bricks, mortar | Steel columns, steel beams |
| Shielding Method | Enclosing steel components within walls or ceilings made of fire-resistant materials | Fireproof boards | Steel roofs |
| Water Spray Method | Installing a sprinkler network to form a continuous water film on component surfaces during a fire | Water | Large spaces |
| Water Cooling Method | Filling hollow components with water to dissipate heat through evaporation or circulation | Water circulation | Steel columns |
Fire-Resistant Paints
Fire-resistant paints are a kind of functional paint. They have the special function of fireproofing. This is on top of the protective and decorative properties of general paints. At present, fire-resistant paint is the most commonly used and convenient method in steel structure fire protection. The fireproof coating can block high temperatures and slow the steel’s heat. It also slows steel’s softening and bending in fire. This gives people time to put out the fire. The fire prevention mechanism says steel structure fireproof coating has intumescent and non-intumescent types.
Intumescent Fireproof Coating
Intumescent Fireproof Coating: Intumescent steel structure fireproof coating, also known as a thin fireproof coating. In a fire, it expands and forms a uniform and dense honeycomb or spongy carbon foam. This isolates the flame from the object. It stops or slows burning and protects steel. Intumescent fireproof coating has the advantages of thin coating, lightweight, good vibration resistance, and good decorative properties. In a commercial building, intumescent fire-resistant coatings slow the heat of the steel. This prevents structural collapse during a fire. So, people can be evacuated in time.
Non-Intumescent Fireproof Coating: Non-intumescent steel structure fireproof coating, also known as thick fireproof coating. It does not expand in case of fire and has good heat insulation. Non-intumescent fireproof coating has good inherent adiabatic and ablative properties. It blocks and consumes fire heat, thus delaying steel from reaching critical temperature. In designing steel warehouse buildings, the use of non-intumescent fireproofing coatings to protect the steel structure, so that it remains stable in the fire, for the fire brigade to fight for valuable rescue time.
Fireproof Boards
The following is the introduction of several common steel structure fireproof boards.
Mineral wool boards and glass wool boards: mineral wool and glass wool are mainly used as heat-insulating materials. It is non-combustible, good in high-temperature resistance, and light in weight.
Fireproof gypsum board: The main component is non-combustible and contains crystallized water, which has better fire resistance and can be used as a partition wall, ceiling, and roofing board. In use, it is lightweight, can reduce the building load-bearing, and processing is easy, construction is convenient, good decorative.
Calcium silicate fiberboard: lime, silicate, and inorganic fiber reinforcing materials as the main raw material for the construction of panels, lightweight, high strength and heat insulation, durability, processing performance, and construction performance is excellent, etc., mainly used for making ceilings, partition walls, and as steel columns and beams of fire protection materials.
| Fireproof Board Type | Main Materials | Application Range | Key Advantages |
| Mineral Wool Board, Glass Wool Board | Mineral Wool, Glass Wool | Partition Walls, Ceilings, Roof Panels | Non-combustible, High-temperature resistance, Lightweight |
| Fireproof Gypsum Board | Gypsum, Non-combustible Crystalline Water | Partition Walls, Ceilings, Roof Panels | Lightweight, Fire-resistant, Easy to process, Good decorative properties |
| Calcium Silicate Fiber Board | Lime, Silicate, Inorganic Fiber | Ceilings, Partition Walls, Fire Protection for Steel Columns and Beams | Lightweight, High strength, Good thermal insulation, Durability, Excellent processing and construction performance |
Fire Spray
Fire protection sprays usually consist of binders, fillers, and fibers and are delivered to the construction site in powder form. Fire protection sprays cause the surface of the steel structure to become rough and are suitable for buildings where aesthetics are not required. Usually, workers engaged in fire spraying must be prepared with protective clothing and respirators, because the spray contains many toxic chemicals to the human body.
Water Spraying
The water spray method is usually set up on the roof’s water supply network. In a fire, the network will spray water. The water will form a flowing layer on the building’s surface. This layer will play a role in extinguishing the fire.
Water-filled cooling method
The cooling method is closed. It’s in a steel column with an internal hollow filled with water. When a fire occurs, the components transfer their heat to the water. The water will evaporate due to the heat. At the same time, the water-absorbed heat will continue to circulate the cooling will heat away.
Conclusion
Fire protection of steel structures, as an important load-bearing structure in buildings, is of paramount importance. Good fire protection can greatly improve building safety and durability. This is true in various sites and conditions. Whether it is the use of fireproof coatings, fireproof panels, or other effective fireproofing methods, they can provide critical protection to the building in the event of a fire, slowing down the spread of the fire and buying valuable time for fire suppression and evacuation.
Especially the increasing number of steel multi-storey buildings, these buildings once a fire, the fire is difficult to extinguish within a short period, so the design of the material must be strengthened to enhance the fire performance of the fire-resistant limit.
If you are planning to construct a steel building or would like to know more about the latest technologies and solutions for steel fire protection, please do not hesitate to contact us. We have the experience and expertise to provide tailored fire protection advice and support for your project.
FAQ
Fire-resistant paints, fireproof boards, and water-filled systems are common methods.
Fireproof boards keep their shape. They are also better for looks. Sprays are easier to apply to complex shapes.
Yes, various standards like BS EN 1994-1-2 and TCVN specify fire safety requirements.
They keep steel temperatures low during fires, maintaining structural integrity.
Regular inspections are essential, typically annually or as specified by local regulations.
