The sound absorption coefficient is a commonly used parameter to characterize the acoustic properties of materials. The fire performance of construction products has to be evaluated on the basis of their reaction to fire performance. The evaluation of the reaction to fire performance for the flammable construction materials which are in Class E reaction to fire is based on the ignitability test and the thermal test using the radiant heat source. For this study, nine types of STERED^® products, which were made from the recycled automotive technical textiles, were chosen in order to evaluate their ability for sound absorption and the reaction to fire. The fire performance was evaluated on the basis of the relative mass loss in the radiant heat source test; the ignitability in accordance with ISO 11925-2, the possible appearance of flame, duration of flame, and the glowing during the single flame source test. The sound absorption of nine products was rated on the basis of the sound absorption coefficient and the noise reduction coefficient. The measurement was performed using the transfer function method in accordance with ISO 10534-2. From the nine tested types of STERED^® products, the product Senizol AT XX2 TL 60 had the lowest mass loss at thermal loads up to 700 °C and it fulfilled the conditions for Class E reaction to fire. This product had the highest noise reduction coefficient of 0.81 and a high absorption coefficient for frequencies ranging between 500 Hz and 2000 Hz. The STERED^® product Senizol AT XX2 TL 60, as well as Senizol AT 22 TL 50, Senizol AT 40 TL 25, Senizol AT XX4 TL 50 and Senizol AT XX4 TL 10 with a sound absorption coefficient α of between 0.80 to 0.95 and corresponding NRCs from 0.66 to 0.81, these STERED^® products can be classified according to ISO 11654 into the sound absorption classes A and B.

The purpose of this paper is to propose a method for the optimization of raw wood for the timber construction industry that would meet the green business and sustainable development requirements within the concept of corporate social responsibility. The methodology conceptually applied the ImageJ software in the process of spruce-timber valuation using 100 log specimens according to the standard STN 480055. The impact of timber structure on the environment compared to silicate buildings was assessed via selected environmental criteria of life-cycle assessment. The methodology was applied according to the standards within the monitored phase of the life-cycle cradle to a gate based on the available environmental products declaration. The overall difference in the assortment value when using the ImageJ software as the evaluation method reached €426.68 (+6.7%). The individual construction elements creating the composition of perimeter walls of the evaluated alternatives showed a positive impact of the following indicators: global warning potential, primary energy input for production, ozone depletion potential, and photochemical ozone creation potential of the reference timber structure. The findings presented in this study clearly confirm the ecological approach toward building a wood-based structure while meeting the requirements of sustainable development.

The aim of the paper is to evaluate the price development of timber assortments in selected countries in Central Europe, to compare the prices and identify the factors influencing the prices, and to quantify the extent of their impact on the prices. A further aim is to predict the price development based on comparing various models for predicting time series of prices. The analyses of the price development was carried out for the assortments of spruce, fir, and beech sawlogs in Slovakia, Czech Republic, and selected Austrian provinces. The analyzed period covered the years from 2001 to 2017 per individual months. Following the selected factors, the study was focused on the timber price development, and subsequently the prediction up to the end of 2019 was calculated. The most significant factor having a negative impact on the price development was the global economic crisis. Following all the prediction methods, the next two years can expect an increase in the prices of sawlogs, except the beech sawlogs in Austria. Analysis of the price developments in the selected countries confirmed that all global factors reflected the price level trends approximately equally in all countries.

The qualitative evaluation of harvested raw logs and sawlogs is mainly based on the quantitative and qualitative evaluation of the visible macroscopic features of the wood. Modern methods allow for the analysis of whole logs by means of computed tomography. These devices can analyze the internal qualitative features of wood that are not visible on the external structures of the logs. The aim of this work was to evaluate the detection accuracy of a CT-scanning device intended for scanning logs on the internal qualitative features of wood using model trunks. Two logs of beech and oak with a length of 4 m were selected for the analysis, based on availability. Qualitative features were identified through computed tomography scanning, visually identified on cut sections, and then manually measured in accordance with applicable legislation. Relatively good agreement was demonstrated for the detected features in terms of identifying their location (dimension in millimeters from the end of the log). For this parameter, the average differences were 0.90% on the beech log and only 1.21% on the oak log. Relatively high accuracy was shown via CT detection of qualitative features in the beech section (with average differences in dimensions of only 3.5%). In the case of the oak log, the dimensions of the quality features were significantly overestimated. These results indicate that CT scanning technology may have a problem with some hardwood species. It was primarily developed for coniferous tree species, and software algorithms are, therefore, not yet fully adapted to the precise detection of the dimensions of individual quality features. Despite the detected differences, it was confirmed that the CT technology of scanning harvested wood can have a fundamental impact on optimization procedures in the recovery and processing of wood. Renting a scanning line for a certain capacity of wood volume appears to be a deployment option for forestry operations and smaller wood processing operations. Thus, this technology can become an important factor in improving the economic evaluation of the final production of wood.

Storage and Fuel Quality of Coniferous Wood Chips

The paper deals with comparing the measurement of noise from the railroads in the residential zone of the town of Zvolen with the results calculated using the prediction methods “Schall 03“ (Deutsche Bundesbahn, 1990) and “Methodical instructions for the calculation of sound pressure level from transport” (MPVHD). The first is used in the Slovakia and second in the Czech Republic. The measurement results and the results obtained from the prediction methods for both measurement locations were evaluated graphically and statistically. The evaluation of the conformity of the measurement with the prediction showed that the results obtained using the method “Schall 03” are in better agreement with the measurement.