Advanced Materials Research Vol. 778

Abstract: The goal of this work was an attempt to understand and model the combined effect of time, geographical location, exposition, and coating type on the physical-chemical mechanisms for wood weathering in structures. A series of wooden samples non coated and coated with top industrial coating has been exposed to natural weathering conditions in seven locations varying in climatic conditions, including whole Italy and southern part of Germany. The set of samples has been exposed for four years, collecting representative samples each year. Four exposition directions (North, South, East and West) were investigated. All the samples have been collected from the field site and stored in a dark and conditioned room including non-weathered reference samples. Measurements of the samples included: photogrammetry, near and mid infrared spectroscopy, color, gloss, roughness and elemental composition (X-Ray Fluorescence spectroscopy). Such a wide set of information collected has been used for investigation of the collective effect of the above mentioned variables on the surface properties of timber structures exposed to weathering. A dedicated algorithm has been tested for modeling the exposure time and service life prediction.

Abstract: Wood as a natural resource is subject to continuous degradation by means of different environmental agents, where fungal decay is one of the main factors affecting timber structure elements. The goal of this work was to monitor and model effects of fungal growth on the chemical-physical properties of Norway spruce (Picea abies L. Karst.). The spectra of wood samples were obtained with near infrared spectrometer and subjected to chemometric analysis. It was found that the white root fungi (Trametes versicolor) affected spectral bands related to lignin and also hemicelluloses. Brown root fungi (Postia placenta, Coniphora puteana, Gleophyllum trabeum) exhibit spectra deviations mostly in the regions related to carbohydrates. However, it was evident that the degradation efficiency of Coniphora puteana was the highest among all the investigated fungi. It was possible to classify the wood samples to clusters separating the investigated fungi. Accordingly, different effects on the strength loss of the wooden members can be identified. It was shown that near infrared spectroscopy has a great potential for in-field assessment of the fungal degradation of wood.

Abstract: Floor structures are an integral part and a valuable element of antique buildings, and the only limitation of their preservation consists in their usage properties. A thorough study of their state of preservation is the starting point for choosing the correct conservation programmes. Currently, fungi are the main reason that leads to the replacement of antique wooden parquets in Poland. Simple visual inspections in many cases do not ensure a precise evaluation of the level of fungal infestation and the depth of penetration of the myceliums hyphae in the wood. Tests of ergosterol, which is a component of most fungis cell membrane, allow us to monitor the level of fungi infestation of diverse materials. This makes it possible to determine the depth of mycelium penetration within the wood quite precisely. Unfortunately, in case of basidiomycota it is not possible to correlate ergosterol with the myceliums biomass nor with the grade of wood degradation. Moreover, tests of ergosterol are not able to answer the question whether the fungi infestation is active, because this substance is also present in dead fungi hyphae. The presence of ergosterol in the wood can only give us a hint of presence of a substrate mycelium, which is responsible for the secretion of exoenzymes that degrade structural substances. Therefore, only the test results of ergosterol content and of the woods chemical composition, wettability curve and moisture equivalent, as well as computer simulations of its capacity to transfer own and usage loads (on the basis of the elasticity modulus, bending strength and wood density) together with the hardness, resistance to abrasion and resistance to scratches of wooden parquets permit us to take a correct decision as to the possibility of their further usage. The research carried out shows that, in many cases, parquets infested with fungi can be used safely. The article presents the proprieties that are important in the correct assessment of antique wooden parquets state of preservation and usage prospects. It specifies the factors that permit to eliminate the problem of fungi infestation and describes the proper usage conditions, proposing efficient methods of conservation.

Abstract: This paper presents results of experimental laboratory establishment of changes in physical properties (swelling, water absorption) of timber (spruce, pine, oak) caused by wood-destroying fungi (Serpula lacrymans, Stereum hirsutum). The experiment was carried out using standard test samples (20x20x30 mm) prepared from new timber and subsequently exposed to the wood-destroying fungi under optimal growth conditions for the period of 10 to 30 days. Changes in physical properties were observed in the damaged samples in compliance with CSN 490126 (equivalent to ISO 4859-1982, equivalent to ISO 4860-1982) and CSN 490104 Czech National Standards. The experiment proved changes in the observed properties depending on the wood and fungi species and the duration of the exposure.

Abstract: This paper introduces the recent attempts to clarify the seismic behavior of traditional timber architecture. The subject of the research is a timber temple, Kencho-ji, in Japan, designated as important cultural property. The temple was affected by the Great Kanto Earthquake 1923. There are two main halls in the Kencho-ji temple, and one of them collapsed while the other slightly inclined. The two main halls have similar structures, and stand next to each other. The authors have been trying to clarify the reason for the difference in the damage for the past ten years through on-sight measurement, micro tremor test, earthquake monitoring and structural analysis. As there is very few information concerning the hidden detail of the joints, recently the authors have operated X-ray inspection. The paper introduces the result of the X-ray test and the structural analysis using the result of the newly revealed hidden joint is discussed.

Abstract: The paper presents an overview on the timber structures of the Royal Palace of Naples. Focusing on the roofs of the Historical Apartment, located at the second level of the palace, different structural typologies are illustrated. The structural identification was achieved starting from an extensive in situ survey, aimed at assessing materials, conservation state, geometries and static schemes. Therefore 3D FEM models of the study systems as whole were set up and the structural analyses carried out, allowing to catch the weaknesses in terms of strength and deformation capacities; the safety checks were performed according to Eurocode 5 provisions. Finally, on the basis of the acquired knowledge, the appropriate retrofitting techniques were suggested [1, . In particular, with reference to the Diplomatic Hall (II), details of the realized restoration interventions, based on mixed technologies, are presented [.

Abstract: This paper reports an in situ inspection project conducted on heavy timber structures of a century-old industrial building at a paper manufacturing facility. A nondestructive inspection procedure was employed to evaluate the true condition of the heavy timbers that serve as the main framing structure of the building. The on-site investigation involved monitoring of the microclimate environment resulting from the paper machine operations, wood species identification, wood moisture content measurements, and internal decay detection using sounding, stress wave timing, and resistance micro-drilling methods. The testing results revealed that numerous locations were in poor condition indicated by widespread internal and external deterioration, reduced cross-sections from fire damages, and multiple failed members. Many timber members in the first floor exhibited a very high level of moisture condition (23 to 55%) as a result of high humidity air created by the paper making operations. This paper also showcases a new way of interpreting the evaluation results as straightforward as possible to the customer by creating 3D model-drawings and colored condition mappings.

Abstract: The Ducal Palace in Sabbioneta, commissioned by Vespasiano Gonzaga in the end of 16th century, keeps four precious wooden ceilings inside. Rough wooden planks nailed to a skeleton structure creates the support for fine wood decorative elements. The requirement of a conservation work has prompted a diagnosis phase about the ceilings as a whole. This was carried out by closed up observations, drilling tests and laboratory analysis.

Abstract: The Structural Concept of the 16th Century Floors of the Ducal Palace in Sabbioneta (Mantua, Italy)

Abstract: The paper aims to inform on the executive phases and on the problems faced during the restoration work on some wooden floors of the sixteenth century Ducal Palace in Sabbioneta near Mantua in Italy, site in the World Heritage list since 2008. The particular historical, artistic and architectural importance of the Palace-and of the floors-required the involvement of expert restorers and a constant control during the work by the Director of works, by the Manager of procedure and by the responsibles of Superintendence for Architectural Heritage and Landscape of Mantua. The paper describes the work performed mainly on wooden structures postponing in another place those relating to the restoration of the decorative elements.