Fire resistance

The fire resistance (also fire resistance ) or the fire resistance class of a component stands for the duration during which a component retains its function in the event of a standard fire . Depending on the tested component, defined requirements and a. placed on the load-bearing capacity , the room closure or the thermal insulation .

The fire resistance period of some proven constructions is cataloged in part 4 of the German DIN 4102, for example. The components and building materials listed here can be deployed and used without a fire test. Fire tests normally have to be carried out as part of the preparation of the usability certificates. The usability of constructions that are not shown in the normative and those that cannot be adequately classified even by means of a fire test can be proven in Germany by means of a general building inspectorate approval , a general building inspectorate test certificate or approval in individual cases.

Classification of the components according to fire resistance classes

The fire resistance, together with other criteria, forms the fire resistance class of a component. For example, a single-leaf (fire protection) door must fulfill the fire resistance function even after a specified number of opening and closing processes (in this case 200,000 cycles). Sometimes a weathering test is required before the fire test.

The fire behavior of the building materials that make up a component must be distinguished from the fire resistance or fire resistance class of a complete component . The fire behavior of the building materials is divided into different building material classes according to DIN 4102-1 and EN 13501-1. A distinction is made between combustible and non-combustible building materials. The type of monitoring or the evidence to be provided for building products is based on the building regulations lists. For building products that are not listed in the Building Regulations List A Part 1 or B Part 1 and which meet the requirements for fire protection, external monitoring and certification of the building product by a notified body (European) or certification is generally required at the European level and in Germany . a recognized testing, monitoring and certification body (Germany) required.

In order to classify a component according to its fire resistance, a test of the fire behavior is necessary (with the exception of components and building materials listed in DIN 4102-4). The reaction to fire is tested in Europe on the basis of European harmonized standards (e.g. EN 13501ff., EN 1363ff. Or EN 13823 for the SBI (Single Item Burning Test)) or in Germany according to national standards (DIN 4102-2 or 4102- 14). The components are classified into fire resistance classes based on the results in accordance with national DIN 4102 or European EN 13501.

Requirements that are placed on a component result from the applicable state building regulations (LBO) or the model building regulations (MBO).

The assembled component must be verifiably made of standardized and monitored material. Furthermore, it is imperative to adhere to the tolerances of the relevant approval (for example, the requirements for minimum thicknesses in DIN 4102-4). For example: A ceiling made of a specified concrete which has achieved a 120-minute fire resistance and has been tested in a thickness of 120 mm may not be used below this thickness if this fire resistance class was required during construction. Such tolerances, such as the minimum thickness of a material, are part of the building approval. The classification is only achieved in construction if the installation of the approved product takes place within the tolerances of the approval. The approval must be valid at the time the product is installed on the construction site.

DIN 4102-2

Fire resistance classes according to DIN 4102-2 and designation according to MBO are:

Fire resistance class short name	Function maintenance over	German designation by the building authorities
F30	30 minutes	fire retardant
F60	60 minutes	highly fire retardant
F90	90 minutes	fire resistant
F120	120 minutes	highly fire resistant
F180	180 minutes	highly fire resistant

Certain components have their own code letters, which are used instead of the general "F" and are described in the parts of DIN 4102 assigned to them:

Q: Walls, ceilings, building supports and beams, stairs
F: fire protection glazing. (F-glazing: prevents the spread of fire and smoke and the passage of thermal radiation)
T: fire barriers (doors, gates and flaps)
G: Fire protection glazing (G glazing: prevents the spread of fire and smoke, the passage of thermal radiation is hindered, but not prevented)
L: ventilation ducts
E: Function maintenance of electrical cable systems
I: Installation shafts and ducts as well as the closures of their inspection openings
K: Shut-off devices in ventilation lines (e.g. fire dampers)
R: Pipe sealing and pipe jacketing
S: Cable insulation
W: Non-load-bearing external walls including parapets and aprons

A component can be further specified by adding the identifier for the fire behavior of the building materials. For example, class F30-B designates a component of fire resistance class F30, which is made of combustible materials in its essential (load-bearing) and other parts. Class F60-AB describes a component that only consists of non-combustible materials in its load-bearing parts.

Partition walls in buildings of building class 4, for example, generally have to meet F60, doors in these walls T30. Fire walls must have a fire resistance rating of F90 and also withstand mechanical impact tests, regulated in DIN 4102-3.

EN 13501

EN 13501 was introduced as a European standard. Part 2 of the standard deals with the fire resistance classes. The classification times of DIN 4102-2 (30, 60, 90, 120 and 180 minutes) are supplemented with the times 10, 15, 20, 45, 240 and 360 minutes.

The performance characteristics of the components are individually abbreviated with the following letters:

R (Resistance): carrying capacity; no loss of stability
E (Etanchéité): space closure; Prevention of fire or gas penetration on the unflamed side
I (insulation): thermal insulation (under fire); Limiting the transfer of heat to the side facing away from the fire
W (Radiation; originally Watt ): thermal radiation; Limitation of the passage of thermal radiation to the opposite side
S (Smoke): smoke tightness; Limiting the passage of smoke in closed rooms
M (Mechanical): Mechanical action; Impact on the wall
C (Closing): self-closing; for smoke protection doors and other fire protection closures
G: Soot fire resistance for exhaust systems
K: fire protection effect; Protection against ignition or charring, for wall or ceiling coverings

In addition, there is information on the direction of the fire resistance period (e.g. i → o, from the inside to the outside in the case of non-load-bearing outer walls) or on test conditions (e.g. constant fire exposure at 500 ° C (r)).

A wall of fire resistance class F90 according to DIN 4102, for example, is referred to as REI 90 according to EN 13501. If this wall is to be designed as a fire wall, it must have the classification REI 90-M (additional criterion impact stress for the fire wall).

Example of a classification according to EN 13501-2: The stability is maintained by a load-bearing wall over a period of 200 minutes, the room closure over a period of 110 minutes and the thermal insulation over 44 minutes. All properties are guaranteed even under shock loads. The classification of this component is: R 180 / RE 90 / REI 30 / REI-M.

In Germany, DIN EN 13501 with parts 1 and 2 has been introduced into the building regulations list 2002/1 ff. (Building regulations list A part 1 annex 0.1.2).

International

Internationally there are many variants with diverse requirements for almost countless components.

In Canada, for example, the Canadian Institute for Research in Construction, part of the National Research Council of Canada , publisher of the Canadian Model Building Code (NBC) specifies special requirements for seals for plastic pipes. Due to the possibly high temperature difference between inside and outside temperatures (for example +20 ° C inside and −40 ° C outside before the fire develops), the Canadian test standard, the application of which is mandatory in the Canadian MBO, requires a positive furnace pressure of> 50 Pa. Hoods in which the overpressure is artificially created must be put on in the test stand. After the fire test has been successfully completed, the bulkhead may also be subjected to a 30 PSI extinguishing water test for a certain period of time.

In the USA , certain fire doors are even allowed to open during the fire test, but only slightly.

Countries without authorization

England and the US nuclear industry are unique in the international construction industry , where no approval is required. Only the test reports are used here, but they do not result in approvals that interpret the test report in a standardized manner. In the NAFTA nuclear power plant sector, it is even common for assembly companies to have the test specimens made in their own workshop without official or independent certification.

This is not allowed in Germany. Legal channels are used there in order to be able to bring manufacturers and assembly companies to justice in the event of damage. However, the evidence is made significantly more difficult by the fact that the exact material properties of the test object are not known, in addition, without a standardized interpretation of an examination report with the following approval, the legal interpretation of the same is disputable in court.

Norms

DIN 4102-2 Fire behavior of building materials and components; Components, terms, requirements and tests .
DIN 4102-3 Fire behavior of building materials and components; Fire walls and non-load-bearing external walls, terms, requirements and tests .
DIN 4102-4 Fire behavior of building materials and components - Part 4: Compilation and application of classified building materials, components and special components .
EN 13501-2 Classification of building products and types of fire behavior - Part 2: Classification with the results of the fire resistance tests, with the exception of ventilation systems .
Model Building Regulations - MBO - last amended by resolution of the Conference of Building Ministers on May 13, 2016.

literature

Frieder Kircher, Rainer Sonntag: Die Roten Hefte, Issue 25 - Preventive Fire Protection . 1st edition. Kohlhammer, Stuttgart 2014, ISBN 978-3-17-016996-8 .
Nabil A. Fouad, Astrid Schwedler: Fire protection design at a glance according to DIN 4102 . Beuth Verlag, 2010, ISBN 978-3-410-21628-5 ( online )
Klaus W. Usemann: Fire protection in building technology: Basics - Legislation - Components - Applications . Verlag Springer, 2002, ISBN 3-642-19001-4 ( online )
Lutz, Jenisch, Klopfer, Freymuth, Krampf, Petzold: Textbook of building physics. Sound - heat - humidity - light - fire - climate. 5th edition. Teubner publishing house, Stuttgart / Leipzig / Wiesbaden 2002, ISBN 3-519-45014-3 .
Wilhelm Scholz, Wolfram Hiese (Ed.): Knowledge of building materials. Werner-Verlag, Cologne 2007, ISBN 978-3-8041-5227-4 .
Katrina Bounin, Walter Graf, Peter Schulz: Handbuch Bauphysik. Sound insulation, heat insulation, moisture protection, fire protection. 9th edition. Deutsche Verlags-Anstalt, Munich 2010, ISBN 978-3-421-03770-1 .
Ulrich Schneider, Jean Marc Franssen, Christian Lebeda: Structural fire protection. National and European standardization. Building regulations. Practical examples. 2nd Edition. Bauwerk Verlag, Berlin 2008, ISBN 978-3-89932-086-2 .
Hans Michael Bock, Ernst Klement: Fire protection practice for architects and engineers. Fire protection regulations and current planning examples. 4th edition. Beuth Verlag, Berlin 2016, ISBN 978-3-410-24746-3 .

Web links

Building material classification according to DIN EN 13501-1 and fire resistance classes according to DIN EN 13501-2 on the website of the Hagebau fire protection alliance

Individual evidence

^ Also in the English BS 476 or in the Canadian MBO - NBC.
↑ Lecture on preventive structural fire protection in the course on safety and security at the Magdeburg-Stendal University of Applied Sciences
↑ 2000/367 / EG: Commission decision of May 3, 2000 on the implementation of Council Directive 89/106 / EEC with regard to the classification of fire resistance of construction products, structures and parts thereof (announced under file number K (2000) 1001)

[1] Also in the English BS 476 or in the Canadian MBO - NBC.

[sga-2] Lecture on preventive structural fire protection in the course on safety and security at the Magdeburg-Stendal University of Applied Sciences

[EU-3] 2000/367 / EG: Commission decision of May 3, 2000 on the implementation of Council Directive 89/106 / EEC with regard to the classification of fire resistance of construction products, structures and parts thereof (announced under file number K (2000) 1001)