Structural Basics - Fire Protection Treatment for Steel Structures
The poor fire resistance of steel structures is well known. Although steel is a non-combustible material, it is highly conductive and susceptible to fire damage, with a fire resistance limit of only 15–20 minutes. Under fire temperatures, the strength of steel structures is a function of temperature. Unprotected steel structures lose one-third, one-half, and two-thirds of their strength when the structural temperature reaches 350°C, 500°C, and 600°C, respectively. When the structural temperature exceeds 600°C, the structure completely loses its load-bearing capacity. Therefore, under fire conditions, inevitably deform and twist, ultimately leading to collapse and destruction.
After a fire breaks out in a steel structure, the structure collapses quickly, posing significant challenges for firefighting efforts and reducing the escape time for trapped individuals. Additionally, the collapsed steel structure often becomes twisted into a ‘twisted rope-like’ or ‘noodle-like’ state, making it difficult to repair and reuse, often resulting in significant loss of life and economic damage.
The essence of fire protection design for steel structures is to select protective materials and determine the required thickness so that the temperature rise of the structure during a fire does not exceed its critical temperature, thereby ensuring fire resistance stability. The objective of fire protection design is to ensure that the actual fire resistance time of structural components is greater than or equal to the specified fire resistance limit.
fireproof coating
Thick-film fireproof coatings: Thick-film steel structure fireproof coatings refer to coatings with a thickness of 8 to 50 millimetres. The fire resistance limit of this type of steel structure fireproof coating can reach 0.5 to 3 hours. During a fire, the coating does not expand. Instead, it relies on the non-combustibility, low thermal conductivity, or heat-absorbing properties of the materials in the coating to slow down the temperature rise of the steel and protect the steel components. This type of fireproof coating for steel structures is composed of an appropriate binder combined with inorganic lightweight materials and reinforcing materials. Compared to other types of steel structure fireproof coatings, in addition to possessing some of the advantages of water-soluble fireproof coatings, this type also has the prominent feature of being cost-effective, as both the base material and most additives are inorganic. This type of steel structure fireproof coating is applied via spraying and is generally used on indoor steel structures with fire resistance limits exceeding 2 hours. However, due to the thick coating, its decorative appearance is relatively poor.
Star Er is a technology-based construction enterprise committed to promoting scientific and technological innovation to lead future life. We have been specializing in steel construction for more than 10 years.
Our products cover all types of steel structure buildings, including various prefabricated metal building warehouse, steel structure workshops, steel structure garages, steel structure poultry houses, steel structure prefabricated houses, etc.
