Konserwacja zachowawcza a trwałość budowli drewnianych

The paper outlines the main problems associated with the durability of wooden buildings in the context of biodegradation. Wood destroying organisms were listed and their climatic requirements were pointed. It was indicated that the main factor affecting the durability of the old historical buildings, was the selection of wood. Traditional carpentry solutions ensuring the durability of timber structures were presented.W pracy zaprezentowano główne problemy związane z trwałością budowli drewnianych w kontekście biokorozji. Wymieniono czynniki biokorozji występujące w architekturze drewnianej oraz ich zależność od warunków klimatycznych. Wskazano główne czynniki wpływające na wielowiekową trwałość budowli historycznych, w tym dobór materiałów. Dokonano przeglądu rozwiązań konstrukcyjnych przyczyniających się do zwiększenia trwałości obiektów, zarówno tych wyrosłych z tradycji ciesielskiej, jak i współcześnie stosowanych zabiegów konserwatorskich

VIDEOENDOSCOPY AS A METHOD OF ASSESSING THE STATE OF WOODEN CONSTRUCTIONS IN HISTORICAL MONUMENTS

Apresentation of an industrial videoendoscope – a new appliance used for the remote observation of inaccessible space without the necessity of disturbing the outer layers. The authors demonstrated the technical potential of the videoendoscope and its application for the conservation of historical monuments. The text also discusses the outcome of research conducted with the assistance of the videoendoscope in Wilanów Palace and the Museum of the Mazovian Village in Siepiec, where it was possible to identify the factors of timber biodegradation – xylophage insects and fungi causing the disintegration of timber – without exposure

Assessment of the Ability for Early Detection of Newly Hatched Larvae of Hylotrupes bajulus L. Using the Acoustic Emission Method in Scots Pine Wood

The acoustic emission analysis method was used to determine the activity of very young Hylotrupes bajulus larvae in their long-term development. In the laboratory conditions the simulated scenario of a fresh, intense infestation inside the construction wood was evaluated. The sounds generated by the insects during their feeding on the wooden samples were processed by the measurement system, which was able to detect and count the larva-originated sound pulses and calculate related energy. So far, no one has examined possibilities of detecting infant larvae of Hylotrupes bajulus L. This work is a continuation of research on the influence of the insect mass on its AE-based detection. The experiments performed with multiple wood samples analyzed through the period of one year have shown dependency between the mass of the larva and the intensity of the sound generated by them. The moment of the earliest possible detection of infestation in the wooden structure was evaluated. In the appropriate conditions (large number of young larvae inside the wood and optimal temperature) the insects reach the mass of tens of mg, which makes them detectable using the AE method

The borings of Teredinidae in fossil wood of Taxodium Distichum Gothan, 1906

The borings of Teredinidae in fossil wood of Taxodium distichum Gothan, 1906. Photographs of borings in fossil wood (Taxodium distichum Gothan, Miocene, Roztocze, Poland) were taken. The texture of the borings surface was analyzed. Moreover, photographs were taken of the surface texture of borings in makore wood (Tieghemella heckelii Pierre) from Africa after Teredinidae and after different species of insects in Scotch pine (Pinus sylvestris L.) for comparative purposes. The photographs were compared. The suspected wood borings in the studied fossil wood of T. distichum were made by mollusc (Teredinidae).Tunele Teredinidae w skamieniałym drewnie Taxodium distichum Gothan, 1906. Wykonano zdjęcia faktury powierzchni ściany tuneli wydrążonych przez Teredinidae w kopalnym drewnie Taxodium distichum z Frampola (Miocen, Roztocze, SE Polska). Dla celów porównawczych sfotografowano tekstury powierzchni ściany tuneli w drewnie makore (Tieghemella heckelii Pierre) z Afryki, pozostałe w sośnie zwyczajnej (Pinus sylvestris L.) po żerowaniu Teredinidae i innych gatunkach owadów. Na podstawie porównania fotografii stwierdzono, że tunel w badanym drewnie kopalnym T. distichum został wydrążony przez Teredinidae

Sinoxylon anale as wood borer insect and its parasites

Sinoxylon anale as wood borer insect and its parasites. A piece of furniture imported to Warsaw from India was used for the investigations. The wood borer insect was defined as Sinoxylon anale Lesne. The wood was hardly damaged by the larvae. There is 4.8 cm3 of wood for one adult who has left wood. In the conditions of high population density of the local population of S. anale only few holes of adults of Chalcidoidea have been found that are parasites. The death of adults in exuvium was probably caused by microorganisms.Sinoxylon anale, jako szkodnik drewna i jego parazytoidy. Do badań wykorzystano mebel, który sprowadzono do Warszawy z Indii. Ksylofagiczny owad, który zniszczył drewno, oznaczony został, jako Sinoxylon anale Lesne. Drewno było bardzo mocno uszkodzone przez larwy. Na jednego dorosłego osobnika, który opuścił drewno, przypada 4,8 cm3 drewna. W warunkach wysokiej gęstości miejscowej populacji S. anale stwierdzono jedynie kilka otworów dorosłych osobników Chalcidoidea, które są pasożytami. Śmierć imago w exuvium była prawdopodobnie spowodowana przez mikroorganizmy

The subjectivity of the estimation of natural wood’s resistance to destruction by termites based on visual assessment in laboratory tests

This study concerns visual assessment of the degree of damage done to Pinus sylvestris L. wood blocks by Reticulitermes lucifugus Rossi, in an experiment conducted according to ASTM D 3345-08:2017. The six evaluators made their assessments individually. The differing results obtained from the evaluators are a cause for concern. Visual assessment of the degree of wood damage can vary significantly from person to person. Measurement of weight loss seems to be a better way of evaluating the degree of damage done to wood samples by termites in laboratory tests

Effects of White and Brown Rot Decay on Changes of Wood Ultrastructure

Fungal decay results in gradual decomposition of compounds of wood cell walls. Mass loss of wood is usually applied to characterize the decay. However, mechanisms of brown and white rot decay are significantly different, resulting in different degradation of components of wood cell walls. Either type of wood decay should differentially influence wood ultrastructure. The traditionally applied descriptors of wood ultrastructure, i.e. crystallinity, the average spacing of the crystal planes and crystallite size, characterize the ultrastructure in an insufficient way. Crystallographic texture analysis was applied in the present study to characterize changes in wood ultrastructure as a result of brown and white rot decay. The Orientation Distribution Function (ODF) was separately determined for wood decayed by brown rot and white fungi and for several levels of mass loss. A series of crystallographic descriptors was derived from the obtained ODFs. The descriptors consisted of texture index, crystalline volume fraction, and skeleton lines of the ODF. The identified crystallographic orientations confirmed different mechanisms of wood decay for brown and white rot fungi. The observations were supported by different rates of changes of the texture index and evolution of crystalline volume fraction