Cone calorimeter tests on FR treated Norway spruce, Comparison of different fire retardant products for timber structures

Fire retardants are effective in reducing different reaction to fire parameters of wood such as the ignitability, the heat release, the burning rate and the flame spread. This paper discusses the different mechanisms of fire retardant products as pressure impregnated wood, non-intumescence surface coatings and intumescence coatings on Norway spruce (Picea abies). The tests were performed by using the cone calorimeter test. The comparison of the investigated products will describe the mechanisms of action to reduce combustion by using the heat release rate of 25 kW/m² and 50 kW/m² and the standard IS0 834 test curve. As result information on the ignition time, the heat release rate, the mass loss and the temperature profile over the material thickness will be presented in this paper

Performance of different fire retardant products applied on Norway spruce tested in a Cone calorimeter

On the European market there are several fire retardant products available, which reach class B in the European classification system. The producers promise their fire retardants are effective in reducing different reaction to fire parameters of wood such as the time to ignition, the mass loss rate, the heat release rate, the total heat release, the charring rate and the flame spread. This paper discusses the performance of fire retardant products as pressure impregnated wood, non-intumescence surface coatings and intumescence coatings on Norway spruce (Picea abies). The investigations are performed by using a cone calo- rimeter test according to ISO 5660. The thermal exposures of the investigations are 50 kW/m2 and the standard IS0 834 test curve. As result information about the heat release rate, the mass loss rate and the total heat release for duration of 900 seconds will be presented in this paper

Einfluss einer wirkenden Biegebelastung auf die dynamischen Eigenschaften von Fichtenkanthölzern/Influence of bending stress on the dynamic properties of spruce timbers

Mithilfe der Ultraschallmesstechnik können über die Schallgeschwindigkeit bzw. den dadurch bestimmten dynamischen Elastizitätsmodul Rückschlüsse auf die Tragfähigkeit von Holzbauteilen geschlossen werden. Einsatzgebiete dieser zerstörungsfreien Methode sind insbesondere Sanierungen von Altbauten oder denkmalgeschützten Gebäuden. Die vorliegende Untersuchung befasst sich mit der Analyse der Abhängigkeit der Schallgeschwindigkeit vom Belastungszustand des zu untersuchenden Bauteiles. An 115 Fichten-Kanthölzern unterschiedlicher Sortierklassen, mit einer Länge von 2,65 Metern, werden im Zuge eines Biegeversuches Ultraschallmessungen in longitudinaler Richtung unter drei verschiedenen Belastungssituationen und an drei über den Querschnitt verteilten Messpunkten durchgeführt. Ein Vergleich der gemessenen Schalllaufzeiten untereinander zeigt eine leichte Vergrößerung der Schalllaufzeiten mit zunehmender Lasteinwirkung, vor allem in den Zonen mit größerer Spannung. Diese Abweichungen bewegen sich jedoch in einem äußerst geringen Bereich, sodass sie bei der praktischen Anwendung der Ultraschallmesstechnik keine maßgebenden Auswirkungen zeigen. Bei der Untersuchung des Einflusses der Durchbiegung auf die Schallgeschwindigkeit konnte im Zuge dieser Untersuchungen keine Korrelation festgestellt werden. Dies bedeutet, dass der Last- und Verformungszustand des Holzes keinen maßgebenden Einfluss auf die Messmethode hat.</p

Performance of different fire retardant products applied on Norway spruce tested in a Cone calorimeter

On the European market there are several fire retardant products available, which reach class B in the European classification system. The producers promise their fire retardants are effective in reducing different reaction to fire parameters of wood such as the time to ignition, the mass loss rate, the heat release rate, the total heat release, the charring rate and the flame spread. This paper discusses the performance of fire retardant products as pressure impregnated wood, non-intumescence surface coatings and intumescence coatings on Norway spruce (Picea abies). The investigations are performed by using a cone calo- rimeter test according to ISO 5660. The thermal exposures of the investigations are 50 kW/m2 and the standard IS0 834 test curve. As result information about the heat release rate, the mass loss rate and the total heat release for duration of 900 seconds will be presented in this paper

Comparison of mechanical properties of thermally modified wood at growth ring and cell wall level by means of instrumented indentation tests

Abstract Thermal modification is a well established method to improve the dimensional stability and the durability for outdoor use of wood. Unfortunately, these improvements are usually accompanied with a deterioration of mechanical performance (e.g., reduced strength or higher brittleness). In contrast, our investigations of the hardness properties in the longitudinal direction of beech wood revealed a significant improvement with thermal modification. Furthermore, we applied instrumented indentation tests on different hierarchical levels of wood structure (growth ring and cell wall level) to gain closer insights on the mechanisms of thermal treatment of wood on mechanical properties. This approach provides a variety of mechanical data (e.g., elastic parameters, hardness parameters, and viscoelastic properties) from one single experiment. Investigations on the influence of thermal treatment on the mechanical properties of beech revealed similar trends on the growth ring as well as the on the cell wall level of the wood structure.</jats:p