Advanced Materials Research Vol. 923

Abstract: The aim of the experiment was to determine the durability of wood based board materials against wood-rot fungi (Serpula lacrymans) effect. The particle boards, oriented strands boards and plywood as the testing materials were chosen. The spruce solid wood as the reference testing material was selected due to the fact that is most common timber species in the Central European region. The testing samples were exposed to wood-rot fungi and in the individual time periods the weight loss (declaring the deterioration process) and mechanical properties (static bending strength and tensile strength perpendicular to the plane of the board) was investigated. It was found that the deterioration of board materials in a very small weight decreases (up to 1.0%) leads to a significant decrease of their strength properties.

Abstract: The problem of finding a suitable diagnostic procedure for the examination of structural elements has been closely analyzed in recent years. In this connection, the main material of interest is wood as a type of heterogeneous matter, and the diagnostic procedure is directed towards enabling prospective industrial application. A new diagnostic method based on X-ray imaging and acoustic electromagnetic waves has been proposed and tested. The X-ray technique utilizes the reduction of the imaging information into 2D planar projection; it allows us to represent clearly the rate of material damage through displaying the weighted damage rate.

Abstract: The wood is traditionally been applied as the building material in building and bridge construction. The number of applications of wood in building structures increases in recent years. According with this trend, the emphasis is on the development of diagnostic and monitoring methods for existing wood structures. In the paper, published results of a survey of existing wood structures in relation to the evaluation of qualitative and quantitative characteristics of the investigated structures. There are finally discussed the possibility to reproduce the results of non-destructive measurement relative to evaluate the strength characteristics of wood.

Abstract: Application of timber structures in civil engineering is completely traditional technology. On the other hand, the materials with better durability characteristics are preferred in present construction. Increased or fluctuating moisture of wood is a significant limiting factor of its life. Wood modification, which results in water intake reduction and also serves to maintain the low equilibrium moisture, may significantly improve the properties of wood, reduces the caused volumetric changes and extends its durability. Utilization of partial or total wood mineralization is just one of the material modification possibilities. This method seems to be promising due to so far gathered results, namely the anti swelling efficiency was greater than 65% for tested wooden species.

Abstract: The paper deals with the influence of climatic factors on selected properties of remedial plaster. The results of experimental measurements of hydrophobicity on samples of plasters after exposure to UV radiation are analyzed.

Abstract: In this paper we present the tests of high temperatures resistances of glass fibre cement plates. The aim of the research was to determine the values of tensile strength in bending for samples subjected to annealing at temperatures 200, 300, 400 and 500 °C in endurance at the highest temperature level for 24 hours. The bending strength was performed according to the norm EN 1170-4. The thermal dilatometric analysis was performed in the temperatures till 540 °C.

Abstract: The paper is devoted to the research and development of modified plasters for restoration and finishing works based on decorative multicomponent cements containing white Portland cement and supplementary cementitious materials (silica fume, metakaolin and fine ground limestone). This cements are similar to Roman cement by their chemical composition. The use of optimal granulometry of decorative multicomponent cements provide directed formation of microstructure of the cement matrix with the formation of stable hydration products. Compositions of modified plasters by the criterions of workability and compressive strength were designed. Physico-chemical modification of plaster by complex air-entraining admixture allows to obtain high-quality modified plasters with improved quality parameters.

Abstract: The paper deals with the stabilization, conservation and strengthening of historic plaster fabrics based on nanofibers. As a result of degradation processes, especially of a chemical nature, accompanied by increased humidity of historic masonry, there is a loss of cohesion and a disturbance of the surface finish and plaster. Traditional remediation techniques and methods normally lead to a reduction of diffuse permeability in the multiphase structure and create different expansion properties under the plaster. The undesirable feature of this method is its irreversible character. Currently there are a number of primarily preferred procedures that stabilize the structure of the external finish, yet at the same time preserve the original features of the historical plasters. This paper will list the partial results of the ongoing in-situ and laboratory research applications of fabric based on nanofibers formed by the supporting layer and spinning polymer.

Abstract: The current approach to the restoration of listed buildings emphasizes the minimization of interference and the maintenance of authenticity and historical value as a whole, alongside detail. This opens a wide field of applications for composite materials and nanomaterials. The use of nanotechnology is currently one of the most reviewed areas of research in various technical disciplines. The extraordinary properties of nanomaterials allow their successful use in the restoration of listed buildings.