Components
Design of the fire load
For the experiments, a fire load density for the use of "residential space" is chosen. According to Osborne et al. [1], this results in a characteristic fire load density of 1085 MJ/m² for the 90% quantile. The fire load for the experiments is implemented in the form of wood cribs. The base areas of the individual wood cribs, evenly distributed in the fire room, each measure 1000 × 1000 mm². They are made of sticks with dimensions B × H = 40 × 40 mm².
The material surface-to-air ratio of the cribs is 1:1. Taking into account the wood moisture content of 14% by weight, the bulk density of 580 kg/m³, and a combustion heat of 17.28 MJ/kg [2] for the wood cribs, the fire load of 1085 MJ/m² described above corresponds to approximately 74 kg/m² of wood, which totals approximately 1.5 tons in the small room (4.5 × 4.5 m²) and approximately 3 tons of wood in the large room (4.5 × 9 m²).
The wooden cribs shown in red represent the two wooden cribs with ignition tubs as a source of fire.
The wooden cribs shown in red represent the two wooden cribs with ignition tubs as a source of fire.
References
- Osborne, L.; Dagenais, C.; Bénichou, N.: Preliminary CLT Fire Resistance Testing Report - Projekt No. 301006155 E-4794, Québec, 2012
- Engel T, Brunkhorst S, Steeger F, Butscher D, Kurzer C, Werther N, Winter S, Zehfuß J, Kampmeier B, Neske M (2022) Schlussbericht zum Verbundvorhaben TIMpuls - Brandschutztechnische Grundlagenuntersuchung zur Fortschreibung bauaufsichtlicher Regelungen im Hinblick auf eine erweiterte Anwendung des Holzbaus (Final report on the TIMpuls research project). Fachagentur Nachwachsende Rohstoffe; Gülzow-Prüzen doi.org/10.14459/2022md1661419
Opening
All compartments have one window opening. The opening factor is selected based on previous investigations and the natural fire curve used in the project, according to DIN EN 1991-1-2:2015-09 NA Annex AA [1], with a value of O = 0.094 m(1/2). This corresponds to an opening of 2.4 × 2.2 m² (width × height) in the small room (T0-T2, 4.5 × 4.5 m²) and 4.2 × 2.2 m² (width × height) in the large room (T3-T4, 4.5 × 9.0 m²). The "window" is open from the beginning. This ensures comparability between the real fire tests and the preliminary basic tests.
Reference
- German Institute for Standardization (2015) DIN EN 1991-1-2/NA National Annex—Nationally determined parameters—Eurocode 1: actions on structures—Part1–2: general actions—actions on structures exposed to fire. German Institute for Stan-dardization, Berlin
Facade Shield
Above the opening of the test room, a facade shield measuring "h x w" 5 x 4.5 m (T0-T2) or 5 x 9.0 m (T3-T4) was installed. This allowed the flame lengths from the opening above the test stand to be measured and assessed in the vertical direction.
The facade shield above the window opening was constructed from cement-bonded sandwich panels mounted on a timber substructure.
The use of cement-bonded sandwich panels was intended to reduce the influence of evaporating water steam to the measurements.
