We present correlations between visually determined characteristics of structural sawn timber produced from Slovenian spruce and its mechanical properties. Dried sawn timber was visually graded into sorting classes according to SIST DIN 4074-1. Results of visual grading were compared with grade determining properties. The most decisive factors to judge lower grade were however knots, followed by twist, the presence of pith and rate of growth. The results of this study represent a basis on which visual grades can be assigned to a strength classes.
COBISS.SI-ID: 1874313
The characteristic properties of Slovenian spruce and fir timber were assessed on 1074 elements with different cross sections. Simple nondestructive methods for the determination of indicative properties of timber and evaluation of their applicability are presented. On the basis of the research, described in the article, we found out that the strength, density and modulus of elasticity, compared to the countries of the “Central and Eastern Europe” growth area, are high enough to grade our softwood species according to European standards into comparable or even higher strength classes.
COBISS.SI-ID: 254377216