Flankenübertragung bei Massivholzkonstruktionen – Teil 1: Verbesserung der Flankendämmung durch Einbau elastischer Zwischenschichten und Verifizierung der Anwendbarkeit von EN 12354

Flanking‐Transmission at Solid Wood Constructions. Part 1: Improvement of Flanking Transmission by Application of Flexible Interlayers and Verification of Applicability of EN 12354. Since solid wood constructions are more frequently applicated for multy‐storey residential buildings the demand for reliable prediction of sound insulation is increasing. Prediction is carried out following EN 12354 which, however, does not contain any input data for solid wood constructions. Therefore, sound‐ and vibration measurements are realized on solid wood test facilities where flanking transmission and input data for standardized predictions are acquired. The normalized impact sound pressure level is calculated for different flexible interlayers and compared to the results of the measurements. Single number quantities show satisfactory accordance between measurement and prediction with deviations between 0 and 2 dB. Considering frequency dependent values major deviations, which can be detected in a certain frequency range, require more accurate modelling.     

Zeitabhängiges Verhalten von Makrokunststofffaserbeton und dessen Einfluss auf die Bemessung von Industriefußböden

Time Dependent Behaviour of Macro Synthetic Fibre. Reinforced Concrete and its Influence on the Design of Industrial Slabs on Ground Material tests and tests on structural elements with synthetic macro fibre reinforced concrete are presented. The experimental program included the investigation of the load carrying capacity and the deformation behaviour under short‐term as well as under long‐term loading conditions. Long‐term load tests were carried out on pre‐cracked fibrereinforced concrete beams to measure the load level above which creep failure can occur. At service load level creep coefficients for a time period of up to three years were determined. Centre point load tests were carried out on concrete slabson‐ground. Two slabs were reinforced with steel mesh and two with synthetic macro fibres only. The tests were performed under short‐term and long‐term loading conditions over a period of 18 month. The current main application of synthetic macro fibre reinforced concrete is slab‐on‐ground. Slabs‐on‐ground can be designed under the assumption of elastic subgrade reaction. The concrete slab itself can be calculated either by elastic theory for uncracked concrete or by yield line theory taking fibre reinforcement into account. Based on the test results of the experimental programme, design recommendations for permanently loaded slabs‐on‐ground are presented.     

Einfluss des Verlustfaktors auf die Schalldämmung von Lochsteinmauerwerk

Effect of loss factor on the sound insulation of hollow block masonry. Sound insulation is known to depend on the loss factor. In solid construction elements the loss factor is largely determined by the energy transfer to adjacent construction elements via the edges, so that the installation conditions influence the sound insulation. This effect is taken into account in the calculation models of EN 12354 through the so‐called in‐situ correction, whereby the overall loss factor of a component tested in the laboratory is converted to an expected loss factor in a real building. This paper illustrates how the loss factor correction should be applied for vertically perforated bricks with possible resonance frequencies from around 800 Hz. It was found that the correction can basically be applied in the same way as for homogeneous masonry, but only up the first resonance frequency of the brick. For higher frequencies the sound insulation was found to be independent of the installation conditions, so that in this range no loss factor correction should be applied.     

Die Wärmeübertragung in porösen Stoffen – Einfluss von Albedo und Extinktion

Heat transfer in porous materials – effect of albedo and extinction. In the context of European market harmonisation it is important to determine the properties of construction and insulation products with minimum measurement uncertainty. For insulation used for industrial equipment and building services the temperature‐dependent thermal conductivity has to be specified for the respective application. However, the established test methods for determining thermal conductivity are not designed for high temperatures. prEN 15548‐1:2006 [4] is a new technical specification designed to meet the requirements of such measurements. In order to be able to compare different types of insulation products, the measuring methods must have approximately the same measurement uncertainty, and the influence factors for the different measuring methods must be clear. For certain products the thickness is a significant influence parameter, which may have different causes. This paper focuses on the so‐called thickness effect.