scholarly journals Characterization of Natural Gypsum Materials and Their Composites for Building Applications

2019 ◽  
Vol 9 (12) ◽  
pp. 2443 ◽  
Author(s):  
Said Bouzit ◽  
Said Laasri ◽  
Mohamed Taha ◽  
Abdelaziz Laghzizil ◽  
Abdelowahed Hajjaji ◽  
...  
Keyword(s):  
Water Content ◽  
High Frequency ◽  
Transmission Loss ◽  
Complete Characterization ◽  
Sound Insulation ◽  
Acoustic Characteristics ◽  
Acoustic Performance ◽  
Heating And Cooling ◽  
Insulation Performance

Building retrofitting plays a key-role in energy saving and a growing interest is focused on insulating materials that allow a reduction in heat loss from envelopes with low thickness, by a process of reducing heating and cooling demand. In this context, a complete characterization of the physical properties of Moroccan natural gypsum materials was carried out. Basic information on the mineralogical, microstructure, thermal, mechanical, and acoustic characteristics of the rocks sampled from two Moroccan regions is provided. It was found that mineralogy, porosity, and water content are the main factors governing the development of the structure and the strength of the samples. The measured values of the porosity were 8.94%, the water content varied between 2.5–3.0% for the two studied typologies, coming from Agadir and Safi, respectively. Gypsum powder was used for fabricating samples, which were investigated in terms of thermal and acoustic performance. Thermal properties were measured by means of a hot disk apparatus and values of conductivity of 0.18 W/mK and 0.13 W/mK were obtained for Agadir and Safi Gypsum, respectively. The acoustic performance was evaluated in terms of absorption coefficient and sound insulation, measured by means of a Kundt’s Tube (ISO 10534-2). The absorption coefficients were slightly higher than the ones of conventional plasters with similar thickness. A good sound insulation performance was confirmed, especially for Safi Gypsum, with a transmission loss-value up to about 50 dB at high frequency.

Study on Acoustic Analysis of a Glass Window by BEM and FEM

2015 ◽  
Author(s):  
Hiroyuki Tanimoto ◽  
Yoshitaka Morimoto ◽  
Keigo Takasugi
Keyword(s):  
Acoustic Analysis ◽  
Transmission Loss ◽  
Plate Thickness ◽  
Performance Measure ◽  
Sound Insulation ◽  
Analysis Model ◽  
Glass Pane ◽  
Acoustic Characteristics ◽  
3D Cad ◽  
Insulation Performance

This research employed acoustic analysis software and established an analytical method for sound transmission loss, which is a sound-insulation performance measure for glass windows. In addition to prediction of transmission loss through vibration of the glass, the research estimated acoustic characteristics that considered transmission loss in the vibration of the frame. Acoustic analysis was conducted with 3D CAD for glass windows of 8 mm plate thickness through preparation of an analysis model under the same conditions as a vibration test. The acoustic analysis also considered both the glass pane and aluminum frame on the side of the sound source. This paper evaluated the results based on analytical values and experimentally observed values.

scholarly journals Kajian Eksperimental Koefisien Redaman Akustik Bahan Pelapis Plat Dek Kapal

2018 ◽  
Vol 3 (1) ◽  
pp. 41
Author(s):  
Wibowo Harso Nugroho ◽  
Nanang J.H. Purnomo ◽  
Hardi Zen ◽  
Andi Rahmadiansah
Keyword(s):  
Absorption Coefficient ◽  
High Frequency ◽  
Transmission Loss ◽  
Base Material ◽  
Sound Insulation ◽  
Insulation Material ◽  
Base Materials ◽  
Specimen Material ◽  
Ship Classification ◽  
Technical Assessment

With the increasingly strict requirements of the ship classification bureau for permissible noise limits to allow passengers and crew to be more comfortable and secure a technical assessment is required to address the characteristics of the noise. A noise beyond the standard allowed in the vessel can be a problem to the ship operators. This noise problem will greatly affects the crews' comfort and passengers. One method to reduce the noise on a ship is to use sound insulation. This paper describes the method for determining the absorption coefficient α and the transmission loss (TL) through an acoustic test of a concrete insulation in the laboratory. The test was conducted by using the method of impedance tube where a speciment response measured by a microphone. In general, the properties of this insulation material remains as the main base material which is concrete. it has been found that the transmission loss value (TL) is in the range of 10 - 50 dB whereas for the base material the concrete is around 22 - 49 dB but the absorption coefficient α of the specimen material is much higher than the material of the base material especially in high frequency, which ranges from 0.15 to 0.97, whereas for concrete base materials have absorbent coefficient α ranges from 0.01 to 0.02.

Research on the Insulation Performance of Sound-Isolating and Decoupled Tiles

2013 ◽  
Vol 457-458 ◽  
pp. 703-706 ◽  
Author(s):  
De Jin Qian ◽  
Xue Ren Wang ◽  
Xu Hong Miao
Keyword(s):  
Large Scale ◽  
Acoustic Radiation ◽  
Single Point ◽  
Mechanical Vibration ◽  
Sound Insulation ◽  
Acoustic Performance ◽  
Operating Modes ◽  
Insulation Effect ◽  
Vibration And Sound Radiation ◽  
Insulation Performance

The acoustic performance of sound-isolating and decoupled tiles is studied from macroscopic and microscopic. First, the sound absorption and reverse sound insulation performance of sound-isolating and decoupled tiles is studied based on laminated media; then the acoustic decoupling materials influence on acoustic radiation of double cylindrical shell underwater is studied, using a double-layer cylindrical structure of large-scale as experimental model .There are large amount of operating modes designed in this experiment, such as all laying, partial laying, laying and so on. The results show that sound-isolating and decoupled tiles not only have the effect of weakening the absorption of reflections, but also have reverse sound insulation effect, which increases as frequency increases; for single point mechanical vibration, the tiles can effectively inhibit vibration and sound radiation of high frequency in the double shell.

Sound insulation performance of pyramidal truss core sandwich structure with frame

2021 ◽  
pp. 109963622110288
Author(s):  
Yu-Zhou Wang ◽  
Li Ma
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Transmission Loss ◽  
Low Frequency ◽  
Sound Insulation ◽  
Geometrical Parameters ◽  
Acoustic Performance ◽  
Truss Core ◽  
Pyramidal Truss ◽  
Wave Angle

Recently, sandwich structures have been widely used in different fields because of their good mechanical properties, but these structures are weak in acoustic performance. In this paper, by combining pyramidal truss core sandwich structure with frame, a new structure is proposed with both good mechanical properties and excellent acoustic performance at low frequency. An analytical model of the pyramidal truss core sandwich structure with frame is developed to investigate the sound transmission loss (STL) performance. Finite element method (FEM) is also used to investigate the STL performance at low frequency. The effects of the incident wave angle and the geometrical parameters on the STL of the structure are discussed.

scholarly journals Physicochemical Characterization of Alginate Beads Containing Sugars and Biopolymers

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Tatiana Aguirre Calvo ◽  
Patricio Santagapita
Keyword(s):  
Water Content ◽  
Digital Image Analysis ◽  
Individual Component ◽  
Physicochemical Characterization ◽  
Alginate Beads ◽  
Complete Characterization ◽  
Ft Ir ◽  
Different Characteristics ◽  
Lower Water Content

Alginate hydrogels are suitable for the encapsulation of a great variety of biomolecules. Several alternatives to the conventional alginate formulation are being studied for a broad range of biotechnological applications; among them the addition of sugars and biopolymers arises as a good and economic strategy. Sugars (trehalose and β-cyclodextrin), a cationic biopolymer (chitosan), an anionic biopolymer (pectin), and neutral gums (Arabic, guar, espina corona, and vinal gums) provided different characteristics to the beads. Here we discuss the influence of beads composition on several physicochemical properties, such as size and shape, analyzed through digital image analysis besides both water content and activity. The results showed that the addition of a second biopolymer, β-CD, or trehalose provoked more compact beads, but the fact that they were compact not necessarily implies a concomitant increase in their circularity. Espina corona beads showed the highest circularity value, being useful for applications which require a controlled and high circularity, assuring quality control. Beads with trehalose showed lower water content than the rest of the system, followed by those containing galactomannans (espina corona, vinal, and guar gums), revealing polymer structure effects. A complete characterization of the beads was performed by FT-IR, assigning the characteristics bands to each individual component.

scholarly journals Indoor Acoustic Comfort Provided by an Innovative Preconstructed Wall Module: Sound Insulation Performance Analysis

2020 ◽  
Vol 12 (20) ◽  
pp. 8666
Author(s):  
Dimitra Tsirigoti ◽  
Christina Giarma ◽  
Katerina Tsikaloudaki
Keyword(s):  
Energy Performance ◽  
Bearing Steel ◽  
Sound Insulation ◽  
Frequency Noise ◽  
Indoor Environmental Quality ◽  
Exterior Surface ◽  
Acoustic Performance ◽  
Insulation Materials ◽  
Acoustic Comfort ◽  
Insulation Performance

The complicated nature of indoor environmental quality (IEQ) (thermal, visual, acoustic comfort, etc.) dictates a multi-fold approach for desirable IEQ levels to be achieved. The improvement of building shells’ thermal performance, imposed by the constantly revised buildings’ energy performance regulations, does not necessarily guarantee the upgrade of all IEQ-related aspects, such as the construction’s acoustic quality, as most of the commonly used insulation materials are characterized by their low acoustic performance properties. From this perspective the SUstainable PReconstructed Innovative Module (SU.PR.I.M.) research project investigates a new, innovative preconstructed building module with advanced characteristics, which can, among other features, provide a high quality of acoustic performance in the indoor space. The module consists of two reinforced concrete vertical panels, between which the load bearing steel profiles are positioned. In the cavity and at the exterior surface of the panel there is a layer of thermal insulation. For the scope of the analysis, different external finishing surfaces are considered, including cladding with slate and brick, and different cavity insulation materials are examined. The addition of Phase Change Materials (PCM) in different mix proportions in the interior concrete panel is also examined. For the calculation of the sound insulation performance of the building module the INSUL 9.0 software is used. The results were validated through an experimental measurement in the laboratory in order to test the consistency of the values obtained. The results indicate that the examined preconstructed module can cover the sound insulation national regulation’s performance limits, but the implementation of such panels in building constructions should be carefully considered in case of lower frequency noise environments.

An improved approach for normal-incidence sound transmission loss measurement using a four-microphone impedance tube

2020 ◽  
pp. 107754632092690
Author(s):  
Zechao Li ◽  
Sizhong Chen ◽  
Zhicheng Wu ◽  
Lin Yang
Keyword(s):  
Transfer Matrix ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Normal Incidence ◽  
Sound Insulation ◽  
Sound Transmission Loss ◽  
The Common ◽  
Wavefield Decomposition ◽  
Insulation Performance

The main aim of this study is to introduce an improved method for determining the sound properties of acoustic materials which is more precise than the common wavefield decomposition method and simpler than the common transfer matrix method. In the first part of the article, a group of formulae for calculating sound transmission loss is represented by combining the wavefield decomposition and transfer matrix methods. Subsequently, a formula for calculating sound absorption coefficients is derived from these formulae by definition. Furthermore, the present formulae are validated by comparing the experimental results achieved with the present formulae and those results obtained by other methods recorded in published articles. Eventually, it is demonstrated that the method can accurately measure the sound insulation performance of materials and the sound absorption properties of limp and lightweight materials.

Impact sound transmission: experiments of control at the receiver room

2021 ◽  
Vol 263 (1) ◽  
pp. 5595-5599
Author(s):  
Davi Akkerman ◽  
Paola Weitbrecht ◽  
Mariana Shieko ◽  
Marcel Borin ◽  
Leonardo Jacomussi
Keyword(s):  
Social Housing ◽  
Sound Transmission ◽  
Field Tests ◽  
Sound Level ◽  
Sound Insulation ◽  
Total Cost ◽  
Acoustic Performance ◽  
The Impact ◽  
Insulation Performance

Considering Impact sound level requirements accomplishment in Brazil, floating floors are still considered as an inviable solution for building companies due to the implications in the total cost of building, mainly for social housing. Alternative and sometimes cheaper solutions are those undertaken in the receiver room. However, the lack of laboratory and field tests on the acoustic performance of this type of system is still a barrier for acoustic designing in Brazil. The aim of this paper is to study and validate different constructive solutions developed jointly with building companies for improving the impact sound insulation performance on the receiving room of new Brazilian housing constructions.

Sound Insulation Performance of Finite Orthotropic Sandwich Panels

2013 ◽  
Vol 377 ◽  
pp. 12-16 ◽  
Author(s):  
Sheng Chun Wang ◽  
Wei Dong Shen ◽  
Jia Feng Xu ◽  
Pei Wen Wang ◽  
Yun Li
Keyword(s):  
Transmission Loss ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Sound Insulation ◽  
Honeycomb Sandwich ◽  
Theoretical Predictions ◽  
Core Thickness ◽  
Insulation Performance ◽  
Good Agreement

A theoretical model for calculating sound transmission loss (STL) of finite honeycomb sandwich panels is developed. The accuracy of the theoretical predictions is checked against experimental data, with good agreement achieved. Numerical analysis shows that increasing face sheet thickness can improve STL effectively, which is much more effective than increasing the core thickness. Core thickness and Youngs modulus of face sheet have evident effect on coincidence frequency, which should not be neglected when predicting STL.

Finite-Difference Time-Domain Analysis of Sound Insulation Performance of Wall Systems

2009 ◽  
Vol 16 (3) ◽  
pp. 267-281 ◽  
Author(s):  
Takumi Asakura ◽  
Shinichi Sakamoto
Keyword(s):  
Numerical Analysis ◽  
Finite Difference ◽  
Energy Loss ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Transmission Loss ◽  
Fdtd Method ◽  
Sound Insulation ◽  
Insulation Performance ◽  
Difference Time

A prediction method for the sound insulation of walls by vibro-acoustical numerical analysis using the finite-difference time-domain (FDTD) method is described. In order to accurately predict the sound insulation performance of walls, numerical modeling of the vibration energy loss of walls in the vibration analysis is necessary. In this study, the energy loss at the boundary part of the plates and the internal damping of the plates are modeled and the sound transmission loss of glass plates and plasterboard walls is calculated. A reasonable agreement is found between the calculation and measurement results and the applicability of the numerical analysis is confirmed.

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