WOOD RESEARCH Volume 61, Number 5, 2016
Adam Krajewski, Paweł Kozakiewicz, and Piotr Witomski

Shear strength of Scots pine (Pinus sylvestris L.) from the historical buildings

Comparative research was conducted on shear strength parallel to grain of heartwood of Scots pine (Pinus sylvestris L.) from the 16-18th century from Central Poland and of modern wood. Tests were performed on 150 samples of aged wood from 13 construction elements of 4 historic buildings and on 100 samples from 10 modern constructional elements. Aged wood revealed a better technical quality. The difference of average shear strength parallel to grain values equaled 0.09 MPa and the translation of correlation line was about 0.35 MPa in favour of aged wood.

WOOD RESEARCH Volume 61, Number 2, 2016
Piotr Mańkowski, Paweł Kozakiewicz, and MICHAŁ DROŻDŻEK

The selected properties of fossil oak wood from medieval burgh in Płońsk

Oak wood is characterized by a high resistance to effects of biotic factors and thereby it is often found in archaeological excavations. While lying over many years in the wet environment, the wood turns black as a result of reaction with iron compounds. Archaeological oak is a valuable raw material. In this paper selected mechanical and chemical properties of a thousand years archaeological oak were investigated. Then the archaeological oak properties were examined and compared with the contemporary oak wood. Archaeological oak wood as well as contemporary oak wood has a directly proportional relationship between MOE (modulus of elasticity) and wood density, and similar relationships between wood density and compressive strength, bending strength, content of mineral substances. Contemporary wood of the same density as the archaeological oak wood would show significantly higher mechanical properties.

WOOD RESEARCH Volume 65, Number 3, 2020
Adam Krajewski, Paweł Kozakiewicz, and Piotr Witomski

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

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 (R2 = 0.5599), and also of contemporary timber (R2 = 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.