Analysis of the influence of the heating process on the charring depth of wooden elements

Abstract

In accordance with European standards in the field of designing wooden structures in the design process and in fire safety engineering, differentiated fire impacts should be applied, depending on the expected scenario of its development. These interactions describe the time-temperature relationship. Fire resistance is generally related to the thermal interaction determined by a logarithmic relationship called a standard curve describing a fire developed in a room in the form. It is possible to use other, more realistic scenarios characterizing the thermal impact determined by the so-called nominal curves covering the effects of fire emanating from a window or hydrocarbon fires (eg in fuel depots). Individual fire scenarios can also be used. The basis for determining the time to the loss of the load bearing capacity of the wooden structure (fire resistance due to the load capacity criterion for a given temperature course over time) is the geometric characteristics of the uncut core of the cross-section. The dimensions of the uncut, working cross section are determined so far only for rods heated according to the standard curve, assuming a charring speed for glued laminated timber of 0.50 -0.80 mm / min depending on the type of wood and product. For other curves, research in this area is lacking.