The European Standards EN 13381-4 and EN 13381-8 provide a comprehensive methodology for testing the effectiveness of fire protection systems applied to structural steel members. These standards focus on different types of fire protection technologies: passive and reactive fire protection systems, respectively. Both play crucial roles in enhancing the fire resistance of structural steel, which is vital in maintaining the structural integrity and stability of buildings during fires.
EN 13381-4: Testing Passive Fire Protection
Passive Fire Protection systems consist of materials that maintain their physical form under fire exposure. Common forms of passive protection include:
- Sprays (with or without mesh reinforcement)
- Rendering
- Mat products and boards
EN 13381-4 details how to measure the physical properties of passive fire protection materials, such as thickness, density, and moisture content. This data is crucial for determining the appropriate thickness of fire protection material needed to achieve desired fire resistance levels, based on test results.
EN 13381-8: Testing Reactive Fire Protection
Reactive Fire Protection involves materials that undergo a physical transformation when exposed to heat. These materials, often intumescent coatings, expand to form an insulating barrier that protects the steel from heat. An intumescent coating (basecoat) is often applied as a system (although not always), along with compatible primer to enhance stickability and topcoat to improve environmental durability.
Stickability
In addition to the insulation performance, both standards evaluate the “stickability” of the fire protection system. This test assesses the ability of the fire protection material to remain adhered and coherent under a range of conditions including deformations, varying furnace temperatures, and steel temperatures. Ensuring the material (or char in case of intumescent coating) stays in place is vital for its effectiveness in protecting the steel from heat.
Assessment
One aspect of these EN 13381 standards is the defined assessment procedure, which analyses temperature data from tests on both loaded and unloaded steel sections. This analysis helps predict how long the steel can maintain a temperature below a critical threshold under specific conditions. The assessment considers factors such as:
- The range of steel sections and their properties
- Section factor
- Thickness of the fire protection material
- Field of design temperatures
This procedure is designed to classify specific fire durations and is best conducted within the same testing laboratory to ensure consistency and reliability in the data and subsequent analysis.
Application
The fire test methodology makes provision for the collection and presentation of data as well as assessments, which can subsequently be used as direct input to the calculation of fire resistance of steel structural members in accordance with the procedures given in EN 1993-1-2 and EN 1994-1-2.
