Comparison of mechanical properties of the eldest larch wood construction with oak wood and spruce wood

The paper discusses mechanical properties of timber for structures – most frequently used spruce wood, historically used oak wood and rarely mentioned larch wood. The main focus is on larch wood extracted from the ceiling of an immovable cultural monument from the 17th century – the determination of its age, its historical importance and mechanical properties. Mechanical properties were obtained by the standard tests in compression parallel and perpendicular to the fibres and in bending. The results of tests are compared to the mechanical properties of oak wood, of commonly used spruce wood and of recently felled larch wood.

Methods for determining the charring rate of timber and their mutual comparison

There are simplified and advanced design methods for the determination of the mechanical resistance of timber structures in fire. The simplified methods have some limitations and in case it is not possible to use the simplified methods, it is necessary to use the advanced ones. These advanced design methods can be analytical or numerical. This contribution deals with the determination of the one-dimensional charring rate depending on time by advanced calculations, focusing on the influence of different input parameters, with the results of an experiment being presented for comparison. The aim of this paper is to show that despite the suitability and conservativeness of the method according to Eurocode 5, there are various cases (different moisture, wood species etc.) when it is necessary to perform numerical or analytical analyses without the possibility to apply standard input parameters. Therefore, this contribution compares individual methods for finding of the most appropriate one.