Ensuring the safety of people and buildings against fire is a regulatory obligation requiring the characterization of the reaction to fire of materials and components in structures. The CSTB performs these tests within its Vulcain facility. It centralizes fire test and reaction-to-fire laboratories approved by the Interior Ministry (amended order of February 5, 1959), along with other special equipment. Thanks to the Vulcain facility, the CSTB can guide stakeholders in improving fire safety in structures by means of COFRAC No. 1-0301 standardized and accredited testing (scope available on www.cofrac.fr). It also performs customized testing for research, consulting and fire safety engineering studies.
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To ensure fire safety in structures, construction stakeholders have two options:
- Meet the performance requirements set forth in regulations for the building components;
- Conduct fire safety engineering studies to check the fire safety levels of structures with respect to their use.
Through its Vulcain fire test facility in Marne-la-Vallée and using its fire safety expertise, the CSTB offers stakeholders the most appropriate approach for their requirements. It performs standardized tests to certify the performance of materials and components in structures. It can also conduct performance-based fire safety engineering studies which aim to ensure that innovations in structures do not deteriorate the level of safety.
Fire tests
The CSTB fire test laboratory determines the lapse of time during which a construction element continues to fulfill its function when burning. The CSTB offers stakeholders a wide range of fire tests at its 2500-m² laboratory, which includes three major test facilities and four supporting installations.
Three furnaces are employed to thermally stress test specimens with standardized (ISO, hydrocarbon fire, etc.) or non-standardized temperature curves. In addition, loading systems enable application of mechanical stresses during testing. Inside the furnaces, endoscopic cameras record visual observations during testing. Outside the furnaces, a stereo image analysis system determines the displacement/deformation fields of the elements in three directions.
- Horizontal Furnace (H furnace) for test specimens up to 4 m long and 3 m wide, or on floors with a mechanical span up to 5 m;
- Vertical Furnace (ISO furnace) for test specimens up to 3 m long and 3 m high;
- Modular Furnace for flat and three-dimensional test specimens: elements up to 9 m high, floors with a span up to 7 m, complete assemblies.
Performing R&D testing of innovative structures with Vulcain
Fire tests for large or complex structures (buildings, industrial sites, transport infrastructure) require the use of special parameters. For this, the CSTB has a one-of-a-kind furnace in Europe. Its modularity makes it possible to perform high-added-value tests on large specimens and those with complex geometries. In its largest configuration, its total power is 13.5 MW (two to four times the power of conventional furnaces). For in-depth understanding of the phenomena observed, it is also possible to combine an experimental approach with digital simulation using special measuring technology.
Furthermore, the CSTB has a mobile furnace for fire tests on elements that cannot be moved. It is used for on-site tests, for example, on poles or walls of industrial installations, for tunnel elements, and for penetration seals in power plants.
Assessing reaction to fire
In its reaction to fire laboratory, the CSTB measures whether a building element contributes to the spread of fire, especially in the first 15 to 20 minutes (about the time to evacuate people and for the fire brigade to intervene).
The testing services offered by the reaction to fire laboratory can be customized for research or assessment requirements and performed in accordance with European (Euroclass system) and French (M classification) regulations. For this, the laboratory has:
- Two Single Burning Item (SBI) test benches for studying the behavior of products when heated;
- One calorimeter to measure the calorific value of products;
- Radiant panels to test floor coverings, ceilings and roofs;
- One ignitability test bench to test the flammability of products;
- One noncombustibility testing furnace.
Performing special tests
Testing external fire spread of facades
The CSTB has a specific facility for measuring external fire spread of facades for regulated buildings (residential buildings, buildings open to the public, high-rise buildings).
Called the LEPIR test, it is used in a two-story configuration. The ignition source is located in a ground floor room. The fire system is controlled by penetrations in the rear wall of the room on the ground floor. Temperature and radiant flux are measured.
Measuring the rate of heat released from large objects
In Saint-Yan, in the Saône-et-Loire department, the CSTB has a test facility comprising a calorimeter hood. This facility enables assessment of instantaneous rate of heat release from large objects subjected to thermal stress.
Its design allows to perform tests in accordance with various benchmarks:
- Roof tests in accordance with ISO 13784-1;
- Cladding and interior coating tests (ISO chamber) in accordance with ISO 9705.
This facility also enables measurement of the rate of heat release from various combustible materials (rubber tyres, electrical cabinets, cables, etc.).
Checking the effectiveness of smoke extraction systems
As a body recognized by the Interior Ministry to be qualified for smoke extraction assessment, the CSTB has mobile facilities for on-site testing of the effectiveness of smoke extraction systems in specific structures.
Developing active fire protection solutions
Assessing sprinkler and water mist systems
Automatic sprinkler and water mist systems are active fire protection systems designed to reduce the intensity of or extinguish fire. They are part of an overall strategy for the safety of people and/or limiting property damage inside buildings.
The CTSB guides project owners and industrial companies in assessing the capabilities of sprinkler and water mist systems to ensure sufficient fire safety on premises. This involves analyzing how these systems interact with others (fire detection, control system, smoke extraction).
To do this, the CSTB has an experimental installation in Marne-la-Vallée consisting of a model room connected to a hallway, similar to that found in residential buildings and buildings open to the public. This test installation can be customized based on specific needs (mechanical or natural ventilation, different hydrant sizes, etc.).
Innovative measuring technology, developed from CSTB research, makes it possible to:
- Measure temperature, opacity (visibility) and fire intensity;
- Assess the impact of extinguishing systems on fire and its spread, and on the evacuation of occupants and the intervention of the fire brigade.
