Apparent impact sound insulation performance of cross laminated timber floors with floating concrete toppings

2021 ◽  
Vol 263 (1) ◽  
pp. 5203-5215
Author(s):  
Jianhui Zhou ◽  
Zijian Zhao
Keyword(s):  
High Performance ◽  
Dynamic Stiffness ◽  
Steel Structures ◽  
Bending Stiffness ◽  
Sound Insulation ◽  
Small Scale ◽  
Cross Laminated Timber ◽  
Mass Timber ◽  
The Impact ◽  
Insulation Performance

Mass timber buildings are gaining increasing popularity as a sustainable alternative to concrete and steel structures. Mass timber panels, especially cross-laminated timber (CLT), are often used as floors due to their dry and fast construction. CLT has poor impact sound insulation performance due to its lightweight and relatively high bending stiffness. Floating concrete toppings are often applied to increase both the airborne and impact sound insulation performance. However, the impact sound insulation performance of floating concrete toppings on CLT structural floors is affected by both the concrete thickness and resilient interlayer. This study investigated the efficiency of both continuous and discrete floating floor assemblies through mock-up building tests using small-scale concrete toppings according to ASTM E1007-16. It was found that the improvements by continuous floating floor assemblies are dependent on the concrete thicknesses and dynamic stiffness of resilient interlayers. The improvements cannot be well predicted by the equations developed for concrete structural floors. The highest apparent impact sound insulation class (AIIC) achieved with continuous floating floor assemblies in this study was 53 dBA, while that of the discrete floating floor assemblies was up to 62 dBA. The discrete floating floor solution showed great potential for use in mass timber buildings due to the high performance with thinner concrete toppings.

Impact sound insulation of cross-laminated timber/massive wood floor constructions: Collection of laboratory measurements and result evaluation

2016 ◽  
Vol 24 (1) ◽  
pp. 35-52 ◽  
Author(s):  
Anders Homb ◽  
Catherine Guigou-Carter ◽  
Andreas Rabold
Keyword(s):  
Prediction Models ◽  
Dynamic Stiffness ◽  
Sound Level ◽  
Sound Insulation ◽  
Cross Laminated Timber ◽  
Wood Floor ◽  
Weak Part ◽  
Floor Systems ◽  
Single Number ◽  
The Impact

Wooden building systems, including cross-laminated timber elements, are becoming more common. The last few years have seen new developments and documentation of innovative types of cross-laminated timber floor assemblies. Regarding impact sound associated to walking persons, running or jumping children, such floor assemblies can be regarded as a weak part. So far, there are no reliable standardized calculation models available, for prediction of impact sound in the entire frequency range. Therefore the design is always based upon previous experiences and available measurements. This article presents the results of a number of well controlled sound insulation measurements of cross-laminated timber/massive wood floor constructions conducted in laboratories. The collection of data and results analysis highlight some basic phenomena. For instance, how structural differences related to the grouping of the constructions change the frequency distribution of the impact sound level and the single number quantities. Another significant result is the influence of the dynamic stiffness of the resilient interlayer of floating floor systems and the mass per unit area of the floors. Based on this analysis, the aim is to identify similarities and carry out simplifications. The data will be further processed and used in the development of prediction models and optimization process of cross-laminated timber floor assemblies.

Changes in Floor Impact Sound Insulation Performance with Time

2015 ◽  
Vol 752-753 ◽  
pp. 698-701
Author(s):  
Kyoung Woo Kim ◽  
Jun Oh Yeon ◽  
Kwan Seop Yang
Keyword(s):  
Physical Characteristic ◽  
Dynamic Stiffness ◽  
Vibration Reduction ◽  
Sound Insulation ◽  
Degree Of Reduction ◽  
Floor Structure ◽  
Reduction Effect ◽  
Sound Reduction ◽  
Insulation Performance

Floating floor structures installed with resilient materials are commonly used to reduce sound from floor impacts. Resilient materials minimize the transmission of vibrations by absorbing shock vibrations occurring on the upper part. The floor impact sound reduction performance of resilient materials is related to the dynamic stiffness, which is a physical characteristic of materials. However, the dynamic stiffness varies according to the increase in the loading time of the load that is installed on the upper part of resilient materials. The dynamic stiffness values increase with an increase in the loading time; an increased dynamic stiffness value decreases the vibration reduction effect. The present study focuses on a floor structure installed with resilient materials, and identifies the degree of reduction in floor impact sound insulation performance with the elapse of time. The insulation of sound from lightweight impact sound decreased with the elapse of time, whereas the heavyweight impact sound did not show significant changes.

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.

Studies of the thermal protective performance of fabrics under fire exposure: from small-scale to hexagon tests

2017 ◽  
Vol 88 (20) ◽  
pp. 2339-2352 ◽  
Author(s):  
Sumit Mandal ◽  
Simon Annaheim ◽  
Thomas Pitts ◽  
Martin Camenzind ◽  
René M Rossi
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Radiant Heat ◽  
Air Permeability ◽  
Small Scale ◽  
Fire Exposure ◽  
Thermal Protective Performance ◽  
Flash Fire ◽  
Protective Performance ◽  
The Impact

This study aims to investigate the thermal protective performance of fabrics used in firefighters' clothing under high-intensity fire exposure. The performance of thermal protective fabric systems with different physical properties was evaluated under laboratory simulated fire exposure. Additionally, the influence of the configuration of the fire exposure tests and modes of heat transfer through the fabrics was also thoroughly investigated. The protective performance was evaluated using the standard small-scale flame [International Organization for Standardization (ISO) 9151:1995] and radiant heat (ISO 6942:2002) exposure tests. Additionally, the protective performance was evaluated under flash-fire exposure using a newly developed hexagon test. The protective performance values obtained from the small-scale (flame and radiant heat) and hexagon (flash fire) tests were compared and discussed. It has been found that a multi-layered fabric with high weight, thickness, and thermal resistance can significantly and positively affect the protective performance. If the air permeability of this fabric is high, it can show a lower protective performance; however, the impact of air permeability on the protective performance is insignificant especially in the case of the hexagon test. Notably, the protective performance can differ under two types of small-scale tests − flame and radiant heat. Also, this protective performance value is generally higher in the case of hexagon test in comparison with the small-scale tests. These differences in protective performance are mainly due to the unique configurations of these tests and/or different modes of heat transfer through the tested fabrics. The findings from this study will guide textile or materials engineers in the design and selection of materials for high performance thermal protective clothing; in turn, it will improve the occupational health and safety for firefighters.

Experimental study on the impact sound insulation of cross laminated timber and timber-concrete composite floors

2020 ◽  
Vol 161 ◽  
pp. 107173 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Xiamin Hu ◽  
Hongwei Gong ◽  
Jing Zhang ◽  
Zhicheng Lv ◽  
...  
Keyword(s):  
Experimental Study ◽  
Sound Insulation ◽  
Cross Laminated Timber ◽  
The Impact ◽  
Composite Floors

scholarly journals TURBULENT OSCILLATORY FLOW OVER RIPPLES AT HIGH REYNOLDS NUMBERS FOR PETA-SCALE SIMULATIONS

2018 ◽  
pp. 95
Author(s):  
Guillermo Oyarzun ◽  
Athanassios Dimas
Keyword(s):  
Coastal Zone ◽  
High Performance ◽  
Oscillatory Flow ◽  
Three Dimensional ◽  
Small Scale ◽  
Poisson Solver ◽  
Execution Model ◽  
High Reynolds ◽  
Wave Induced ◽  
The Impact

Surface waves in the coastal zone induce oscillatory flow motions in the vicinity of the seabed. These wave-induced coastal flows interact with the sandy seabed and modify the bed shape by generating coherent small-scale bed structures, which are generally known as ripples. The presence of ripples in oscillatory flows is important due to the impact they have on the seabed roughness and how they affect the near-bed boundary layer hydrodynamics. Simulations of higher and more real-scale Reynolds number (Re) require the use of supercomputers in order to obtain results in a reasonable amount of time. However, the constant evolution of the computing facilities makes the development of parallel algorithms a rather difficult task. The objective of the proposed research is to advance in the comprehension of coastal processes utilizing high performance computing (HPC) for the numerical simulation of the three-dimensional, turbulent flow, which is induced in the coastal zone by wave propagation. In particular, our CFD code (SimuCoast) has been developed using a hybrid MPI+OpenACC execution model that increases its scalability and allows it to engage the vast majority of high-end supercomputers. Special attention has been paid in the parallelization strategy of the Poisson solver that is the most computational demanding operation.

Acoustic design tools for estimation of sound insulation performance of wood wall and floor assemblies

2021 ◽  
Vol 263 (6) ◽  
pp. 267-274
Author(s):  
Cheng Qian ◽  
Lin Hu ◽  
Christian Dagenais ◽  
Sylvain Gagnon
Keyword(s):  
Prediction Models ◽  
National Research Council ◽  
Design Tool ◽  
Sound Insulation ◽  
Prediction Tools ◽  
Minimum Requirements ◽  
Sound Transmission Class ◽  
Interior Walls ◽  
The Impact ◽  
Insulation Performance

The National Building Code of Canada 2015 stipulates the minimum requirements of the airborne sound insulation transmission through common interior walls and ceiling/floor assemblies. The required minimum Apparent Sound Transmission Class (ASTC) is 47 in Canada, whereas the Impact Insulation Class (IIC) for floors is recommended to be higher than 55. For many years, significant efforts were made to develop sound insulation prediction models or tools to predict the sound insulation performance of wall and floor/ceiling assemblies at the design phase in order to meet the requirements and the recommendations made by codes. However, today few models can provide a reliable acoustics design tool. In this document, three prediction tools thought to be practically useful are presented and evaluated. Between these three prediction tools, one is an analytical model of the Insul software while the other two are empirical models developed by the National Research Council of Canada and the American Wood Council. This paper compared the STC and IIC ratings of wood wall and floor assemblies estimated by these three models and verified them by the measured STC and IIC ratings. This work aims at providing an idea for readers to choose a suitable design tool to proceed with their acoustic designs.

The Effect of Chevrons on Crackle: Engine and Scale Model Results

2011 ◽  
Author(s):  
Steve Martens ◽  
John T. Spyropoulos ◽  
Zac Nagel
Keyword(s):  
High Performance ◽  
Jet Noise ◽  
Scale Model ◽  
Small Scale ◽  
Mixing Enhancement ◽  
Noise Component ◽  
Acoustic Environment ◽  
Jet Mixing ◽  
Near Term ◽  
The Impact

GE and the USN continue to work together to find and develop practical techniques to reduce jet noise on tactical aircraft such as the F/A-18 E/F/G. Noise is an important issue for the Navy because of the harsh acoustic environment induced during operations of these aircraft on aircraft carriers and the impact to communities around Naval Air Bases and training sites. The noise generated by these systems is predominantly the noise generated by the exhaust plume due to the low bypass ratio of the engine and very high exhaust jet velocities. The main components of this jet noise are the jet mixing, shock and crackle noise. The present paper reports on progress, following Reference [1] with the F/A-18 E/F/G jet noise reduction program, which is currently focused on the USN near term goal of up to 3 dB reduction in the peak directivity direction. This goal also includes the reduction of the shock and crackle noise components. These goals are currently being pursued with nozzle plume mixing enhancement employing mechanical chevrons. These chevrons can be incorporated in the production version as a redesign of the F414 nozzle seals and do not involve the introduction of additional parts to the nozzle. This paper focuses on the effect of chevrons on the crackle noise component both in full scale on the F404 engine, and in small scale on the F414 engine nozzle in the twin configuration. The paper aims to make the case that this effect, which was first observed during ground engine testing of prototype chevrons, is a beneficial one in reducing/eliminating crackle which continues to be prevalent in high performance tactical aircraft engines today.

scholarly journals Comparison between Chinese Code and Eurocode on the impact sound insulation requirements of the residential floor

2019 ◽  
Vol 275 ◽  
pp. 05001
Author(s):  
Xiaoyu Zhang ◽  
Xiamin Hu
Keyword(s):  
Experimental Data ◽  
Physical Performance ◽  
Critical Index ◽  
Residential Building ◽  
Sound Insulation ◽  
Effective Measure ◽  
Limit Value ◽  
The Impact ◽  
Insulation Performance

At present, the impact sound insulation performance of the residential floor attracts increasing attention, which is a critical index to evaluate the physical performance of the residential building. Improving the sound insulation performance is an effective measure to improve the living quality and solve the contradictions between neighbors. Therefore, many sound insulation standards have been established to guide the design of building sound insulation. In this paper, comparisons between Chinese code and Eurocode on the impact sound insulation requirements of the residential floor were presented, including the evaluation parameter and the limit value of sound insulation. In addition, the applicability of limit value of sound insulation standard for each country was analyzed in detail through the existing experimental data of different floor structures, and then reasonable suggestions were put forward.

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