Teil 2: Trittschalldämmung — Flankentrittschallpegel und Trittschallminderung

Sound protection of cavity floors. Part 2: Impact sound insulation — namely impact sound flanking level and impact sound reduction In part 1 [1] of this three‐part report on cavity floor sound protection, the history of the development of cavity floors introduced on the market since the early 1980s, the main design principles of such floors, and the concepts of flanking level reduction and weighted standard flanking level difference were illustrated. This second part examines two aspects of impact sound insulation, namely impact sound flanking level — previously sometimes referred to as horizontal impact sound insulation — and impact sound reduction. The following discussion of these two impact sound insulation parameters is based on approximately 150 measurements in an acoustics laboratory. The bulk of the measurements was carried out according to DIN 52 210 [3], more recent measurements according to DIN EN ISO 140‐12 [4].     

Teil 3: Anwendung von Laborergebnissen in der Baupraxis,Ausführungsfehler

Sound protection of cavity floors. Part 3: Application of laboratory results in practice; pitfalls during construction This third part of the three‐part „Sound protection of cavity floors”︁ series relates the laboratory examination and analysis of the acoustic parameters of cavity floors to the application in practice. Part 1 [1] described the historic development of cavity floors since the 1980s and the main airborne sound protection parameters, i.e. the standard flanking level difference (airborne sound protection for horizontal transfer, flanking level reduction) and the sound insulation of solid ceilings with cavity floors for vertical sound transfer. Part 2 of the series [2] described the impact sound insulation parameters, i.e. the weighted impact sound reduction (impact sound improvement) and the weighted flanking impact sound level (weighted standard impact sound level for horizontal transfer). This third part suggests cavity floor design options for meeting the required sound protection levels that may exist either in the form of minimum requirements stipulated by building authorities or through civil law agreements between users and investors.     

Schalldämmung und Schall‐Längsdämmung von Fassadenkonstruktionen im Prüfstand – Erkenntnisse für die bauakustische Beratung in der Praxis

Airborne sound insulation and flanking sound insulation of façade constructions (Curtain wallings) in the test stand – findings for acoustic consulting in practice. Based on serial and single measurements for the determination of the weighted sound reduction index and of the normalized flanking sound insulation in horizontal and in vertical transmission direction of façades effects of the measurement procedure and of constructive façade details onto the measurement result are shown. For the performance of measurements of the weighted sound reduction index of façade constructions the possibility of the utilization of German standards DIN ENISO140‐3 in a test stand for wall constructions or of the in field procedure of DIN ENISO140‐5 in a test stand for the determination of the flanking sound insulation of façades is possible. Because the two measurement procedures lead to measurement results with systematically differences for the same façade construction, next to the formal aspect of the communicability of the two measurement procedures the mounting situation of façade elements in the test stand is taken into account. The influence of constructive details of the façade construction and their detailed effect on the determined weighted sound reduction index and/or the determined normalized flanking level difference is supposed to be shown due to carried out measurements of different façades. To that size, kind and order of the glazing, carrying out of façade molliums and façade transoms as well as construction of the façade connecting element as a single‐element for the determination of the normalized flanking sound insulation of a façade construction are taken into account.     

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.     

Zur Prognose der Schalldämmung zweischaliger Membrankonstruktionen

Transmission‐loss prediction for double‐leaf membrane constructions. The sound transmission loss of double‐leaf membrane constructions can be predicted quite well, if the cavity between the membranes contains absorptive material. This is exemplified by a construction with a membrane distance of 20 cm and a 10 cm thick, open‐porous foam plate inside the cavity. The program LAYERS is used for the calculations. A previously applied approximate formula is inappropriate, because it does not correctly account for the incidence‐angle dependency of the sound transmission. In principle, a LAYERS prediction is also possible with an “empty”, only lightly damped cavity. However, the results are less accurate, since information about the absorption within the air or gas space and at the boundaries is scarce. Further uncertainties pertain to the distributions of incidence angles in testing facilities and their influence on the sound transmission loss.     

Schall‐Längsleitung im Holz‐Mischbau

Flanking transmission of timber elements in the building shell with concrete construction parts. The following article describes the test of the flanking transmission of timber elements in the building shell with concrete construction parts for high rise buildings and the effects of different construction methods, like multi‐storey elements, separation boards and the influence of installation layers. The version with the junction of the elements on a level with the ceiling elements and the design of an installation layer cause an substantial improvement of the normalized sound pressure level difference.     

On the sound insulation of masonry wall façades

In this paper, laboratory measurements of sound reduction index for two types of cavity walls commonly used in façades are presented. The first type consists of “masonry–air cavity–brick” and the second one consists of “masonry–air cavity–-gypsum board”. Data are used to show that masonry walls with gypsum boards provide higher sound insulation than masonry cavity walls. The influence on sound reduction index of apertures made on external leaf of the wall to ventilate the cavity of the wall is also examined.     

高层住宅地下室水泵噪声的治理

某高层住宅地下室2层中设置的水泵产生噪声,1层、2层住户房间内超过了国家规范的要求,住户提出意见,通过对噪声源、噪声传播途径的分析,确定了本例中噪声超标的主要原因是固体声的传递,采取了噪声源减噪、设置吸声设施、加设隔声设施等治理措施,有效降低了1层、2层房间的噪声,取得了良好的治理效果.     

Schallschutz mit schalldämmenden Lüftungsgittern

Sound protection using sound‐absorbing ventilation grilles. Sound‐absorbing ventilation grilles are used for supply and exhaust air openings in buildings, in naturally ventilated multistorey car parks, and for screening noise‐emitting equipment requiring a flow of air. The sound insulation of different ventilation grilles was measured in the laboratory. A nomogram taking account of the gap length and width was developed for estimating the weighted sound reduction index of typical sound‐absorbing ventilation grilles. Suggested spectrum adjustment values for the weighted sound reduction index are provided.     

Teil 1: Entwicklungsstand und Flankenpegeldifferenz

Sound protection of cavity floors Part 1: State of the development and difference in flanking transmission level After more than 20 years of development, a summary of current insights regarding the sound protection of cavity floors is provided, based on more than 500 measurements in an acoustics laboratory and several hundred measurements on site, with the latter invariably taking account of the combined effect of walls, ceilings, cavity floors and other components.     

城市绿地群落降嗓效应研究

通过室内装置测量植物的隔声量,比较不同植物类型的隔声效果,并通过野外实测,分析不同植物群落的降噪效果及其影响因子,为降噪绿地构建提供依据。     

发动机消声室设计工程实例

发动机是拖拉机噪声的主要声源.为了解决拖拉机噪声问题就需要建造相应的试验设施,发动机整机半消声室就是其中一项.针对典型的工程实例,从消声室的结构形式入手,依据振动与声学原理,探讨了固体传声与振动声辐射问题,建立了一套发动机半消声室的隔振消声设计方法,成功地解决了消声室背景噪声问题.     

Schallschutz zwischen Reihenhäusern mit unvollständiger Trennung

Sound insulation between terraced houses with incomplete separation. Between terraced houses with double‐leaf partition walls a high quality of sound insulation can be accieved even with suitable structures to go through and attaced to the ground. Therefore it is required to have a sufficient high mass per unit area of the structures to go through, to have a sufficient high mass per unit area of the double‐leaf partition wall and to have a suitable spartial arrangement of the living rooms (floor plan). Different qualities of separation have to be distinguished. It is suggested, to establish a qualtitative ΔR_w‐additional for the prediction and calulation of the sound insulation in the German Standard DIN 4109. Measuring results of the frequency dependent reduction of the impact sound pressure level at the double‐leaf partition wall are presented.     

楼板隔声材料的撞击声隔声实验室测量结果研究

隔声降噪问题越来越成为住宅品质的关注方向,尤其是上下楼层之间的撞击声隔声,隔声地板、隔声砂浆、隔声涂料及隔声垫等隔音材料应运而生。本文对比了这4种产品的计权撞击声压级和计权撞击声压级改善量的实验室测试结果。结果表明,这4种隔音材料的隔声效果、隔声原理和施工要求各有特点,在一定厚度、一定密度下均能改善基础分户楼板的计权撞击声压级,并达到标准要求。     

钢纤维高性能混凝土在声屏障中的应用

在高速铁路的降噪系统中,混凝土声屏障因其降噪效果好、造价低和施工方便正越来越受欢迎。壳体材料选择和结构设计是制作高强轻质混凝土声屏障单元板的关键。为提高台风区高速铁路声屏障单元板的抗弯强度,壳体材料采用钢纤维高性能混凝土。通过计算、试验并结合施工因素,声屏障单元板壳体最小壁厚取25mm,内空腔取消隔板。有限元分析结果表明,其在最不利工况——背板在7.0kPa弯曲荷载作用下,壳体最大拉应力小于钢纤维高强混凝土材料抗拉强度值9MPa。经试验性能研究:背板在高达8.0kPa弯曲荷载作用下,单元板没有开裂破损,跨中挠度较小;单元板降噪系数达0.75,隔音量40dB,均优于要求标准。研究表明该单元板自重小,强度满足台风地区高速铁路的抗弯性能要求,吸音性能优良。     

住宅设计中应高度重视楼板隔声问题

针对目前建筑设计中不重视楼板隔声,普通混凝土楼板撞击声隔声量不能达到国家标准不大于75dB的问题,提出采用浮筑地面、木地板装修、或粘贴阻尼板等技术手段,改善隔声性能,达到相关建筑隔声设计标准。     

Schallschutz von Bauteilen aus mineralischen Baustoffen in Abhängigkeit von der Abbindezeit

Sound protection of structural components made from mineral materials as a function of the setting time. For structural components made from mineral materials, e.g. slabs and walls made from masonry or concrete, screed or cavity floors, the acoustic properties relating to impact and airborne sound protection are expected to change over time. This is due to the fact that the strength increases during the setting process while the mass decreases during the drying process. This article describes the sound insulation characteristics of typical structural components over time during the setting/drying process and defines the intervals after which the state reached after 28 days can be determined with acceptable accuracy.     

Untersuchungen zur Homogenität von Bauwerksteilen mit Lasertechniken

Investigations concerning homogeneity of building parts by laser techniques. The subproject B1 “Diagnostics and Quality Control by Non‐Destructive, Contactless Testing Techniques” is working within the CRC 524 on the procedural and measurement technological evolutionary development of the conventional ultrasonic through‐transmission method towards an optical measuring method by application of laser technologies. The aim is the determination of the distribution of elastic characteristic parameters for the evaluation of laboratory test specimens in investigations on durability of concrete and for the actual state of construction elements in the course of revitalising buildings. In this case, a laser induced sound excitation takes place by means of an Nd:YAG‐laser. The sound waves that have been influenced by the investigation object are detected by a laser vibrometer. By applying these methods, both a high lasing rate and a high achievable data density are to be expected since the laser beams in both systems can be deflected optically by means of scanners. Furthermore, a surveying‐technological approach for sound path determination at each pair of measuring points has been developed, which can also be used for the conventional application of the ultrasonic through‐transmission method.     

Vergleichende Untersuchung raumakustischer Konzepte von Mehrpersonenbüros hinsichtlich Sprachverständlichkeit,Arbeitsgedächtnisleistung und Arbeitsbehaglichkeit durch Hörversuche

Comparative studies of room‐acoustic concepts for open‐plan offices with regard to speech intelligibility, short‐term memory perfomance and acoustic comfort. Increasing use of tempering the core of reeinforced concrete ceilings of open‐plan offices for cooling and if necessary for heating strongly limits the implementation of sound‐absorbing ceilings. In these cases the classic concept for offices with fully sound‐absorbing ceilings and screen barriers is not applicable anymore. As an alternative to this concept of screen barriers a so‐called partition wall concept is going to be implemented in these open‐plan offices. In this case a sound‐absorbing ceiling is not used anymore; instead room‐high partition walls are mounted, which are highly sound‐absorbing on both sides. The objective of the study was to compare these two concepts for open‐plan offices regarding speech intelligibility on the phone, ability to concentrate and acoustic comfort. In addition to that the effect of low‐frequency absorbers was investigated. To evaluate the acoustic concepts of theses offices audibility tests were conducted. For this purpose the room‐acoustic conditions of the office situations were auralized with the help of measured binaural room impulse responses of original open‐plan offices. For comparison an open‐plan office without room‐acoustic measures was included. With this procedure different office situations are directly comparable.     

Tragmodelle zur Bestimmung der Längsschubtragfähigkeit des Kronendübels als neuartiges Verbindungsmittel im Verbundbau

Design model for calculating the longitudinal shear force capacity of a crowndowel. The geometrical shape of the shear connector is a new one and has been developed at the Institute for Structural Engineering at the Vienna University of Technology. In this paper two design models for calculating the longitudinal shear force capacity of a crowndowel are presented. The assignment is to ensure a combined virtue of the steel and of the concrete cross‐section by acceptance of the shear flow in the contact joint. Basic concept of these models is the definition of the longitudinal shear carrying capacity with the load‐bearing capacity of the full plastic steel crown. A comparison with physical experiments shows the suitability of the given models for correct predicting of the longitudinal shear carrying capacity of new shear connectors. For the verification of the load carrying model results of nonlinear FE‐analyses using the program package ABAQUS are given.