COMPARISON OF SELECTED PROPERTIES OF NATURAL AGED WOOD AND CONTEMPORARY TIMBER OF PINUS SYLVESTRIS L. INVESTIGATED USING STANDARD METHODS AND MEASURING OF TRANSITION SPEED OF ULTRASOUNDS ALONG THE FIBRE

摘要

Scots pine wood (Pinus sylvestris L.) is the most common wood material used in historical buildings in many parts of Central and Eastern Europe. Experiments were conducted natural aged wood (263 - 459 years old), extracted from construction elements of four historical buildings (from seven construction elements), and contemporary wood extracted from 5 construction elements. A strong relationship was observed between density and static bending strength (MOR) of natural aged wood (R-2 = 0.5599), and also of contemporary timber (R-2 = 0.7863). Antique wood compared to contemporary wood with the same average moisture content and density is characterized by significantly lower modules (static and dynamic), the speed of ultrasonic waves transitions, and bending strength. Differences in these properties increase with increasing wood density.