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Acoustical Guide: Acoustic Research Report on Mass Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1839
Year of Publication
2018
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Other Materials
Application
Floors
Organization
AcoustiTECH
Editor
Dompierre, David
Garant, Samuel
Publisher
AcoustiTECH
Year of Publication
2018
Format
Book/Guide
Material
CLT (Cross-Laminated Timber)
Other Materials
Application
Floors
Topic
Acoustics and Vibration
Keywords
Mass Timber
Sound Absorption
Impact Sound Insulation
Research Status
Complete
Summary
AcoustiTECH is a North American leader in acoustic solitions and has quickly become the reference standard in the industry. For 25 years, AcoustiTECH has teamed uo with Architects, builders, general contractors, acoustic consultants and other stakeholders to help them achieve their vision by providing proven acoustical solutions and expertise. AcoustiTECH looks at the specific requirements of each individual project, evaluates the requirements, determines the needs and provides personalized solutions. AcoustiTECH's approach is unique, efficient and reliable. We possess our own acoustic laboratory that we use for our research and development in order to recommend the best acoustic solutions by type of structure. Thousands of tests have been performed inclusing over 300 on heavy timber assemblies. The principal objective of creating this document is for the professionals to compare and choose from 25 assemblies the ones that suit their needs the best. The most interesting and popular assemblies have been selected and compared side by side in the same environment, built and tested by the same professional unisg the same flooring materials. It is important to note that the quality of construction can affect the performance. Indeed, construction standards and assemblies recommendations must be followed in order to reach the seeking performance.
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Acoustics Summary: Sound Insulation in Mid-Rise Wood Building

https://research.thinkwood.com/en/permalink/catalogue750
Year of Publication
2014
Topic
Acoustics and Vibration
Design and Systems
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Author
Schoenwald, Stefan
Zeitler, Berndt
King, Frances
Sabourin, Ivan
Organization
National Research Council of Canada
Year of Publication
2014
Format
Report
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Design and Systems
Keywords
Mid-Rise
Sound Insulation
Impact Sound Transmission
Airborne Sound Transmission
Research Status
Complete
Summary
This report summarizes the acoustics research component regarding sound insulation of elements and systems for the research project on mid-rise and larger wood buildings. The summary outlines the background, main research considerations, research conducted and major outcomes. Further details of the design and the results can found in the appendix of Client Report A1-100035-02.1. The goal of the acoustics research components was to develop design solutions for mid-rise wood and wood-hybrid buildings that comply both with the current National Building Code of Canada (NBCC) 2010 [2] requirements for direct sound insulation and with the anticipated requirements for flanking sound transmission in the proposed, 2015 version of the NBCC. In addition, the design solutions were to provide better impact sound insulation while still achieving code compliance for all other disciplines (interdependencies) as identified in the final report of the scoping study conducted in FY 2010/2011.
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Acoustic Testing of CLT and Glulam Floor Assemblies

https://research.thinkwood.com/en/permalink/catalogue1863
Year of Publication
2016
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Sabourin, Ivan
Organization
National Research Council of Canada
Publisher
Regupol America
Year of Publication
2016
Format
Report
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Transmission Loss
Impact Sound Transmission
Impact Sound Pressure Level
Research Status
Complete
Series
Nordic Engineered Wood Report
Summary
This report contains the transmission loss (TL) results measured in accordance with ASTM E90-09 and the normalized impact sound pressure level (NISPL) results measured in accordance with ASTM E492-09 of 13 cross-laminated timber (CLT) floor assemblies and 5 glulam floor assemblies. The report also contains the nonstandard impact sound pressure level results measured on 6 different small patch specimens. Summary tables containing the specimen number, sketch, short description, the sound transmission class (STC) and impact isolation class (IIC) ratings, as well as, the page number of the detailed test reports are provided starting on page 5. A brief analysis of the floors tested as part of this test series is provided after the summary tables on page 9. The standard test reports of the tested floor assemblies begin on page 16. The floor assemblies were built and tested between January and April 2016.
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Airborne and impact sound performance of modern lightweight timber buildings in the Australian construction industry

https://research.thinkwood.com/en/permalink/catalogue2948
Year of Publication
2021
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Jayalath, Amitha
Navaratnam, Satheeskumar
Gunawardena, Tharaka
Mendis, Priyan
Aye, Lu
Organization
The University of Melbourne
RMIT University
Publisher
Elsevier
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Impact Sound Transmission
Airborne Sound Transmission
Simulation
Research Status
Complete
Series
Case Studies in Construction Materials
Summary
Timber usage in the Australian construction industry has significantly increased due to its strength, aesthetic properties and extended allowances recently introduced in building codes. However, issues with acoustic performance of lightweight timber buildings were reported due to their inherit product variability and varying construction methods. This article reviews the recent literature on the transmissions of impact and airborne sounds, flanking transmission of timber buildings, and the state of computer prediction tools with reference to the Australian practice. An in-depth analysis of issues and an objective discussion related to acoustic performance of timber buildings are presented. Timber is a lightweight material and shows low airborne sound resistance in low frequency range. Attenuation of sound transmission with addition of mass, layer isolation, different products like cross-laminated timber and prefabrication are discussed. Challenges in measuring sound transmissions and reproducibility of results in low frequency ranges are discussed. Well-defined measurement protocols and refined computer simulation methods are required. The serviceability design criteria for modern lightweight timber applications in Australia need to be re-evaluated in the area of impact generated sound. Developing computer tools to predict airborne and impact sound transmission in lightweight timber buildings is quite challenging as several components such as timber members and complex connections with varying stiffnesses are non-homogeneous by nature. Further, there is a lack of experimentally validated and computationally efficient tools to predict the sound transmission in timber buildings. Computer prediction tools need to be developed with a focus on mid-frequency transmission over flanks and low-frequency transmission of timber and prefabricated buildings.
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Correlation Between Sound Insulation and Occupants' Perception - Proposal of Alternative Single Number Rating of Impact Sound, Part II

https://research.thinkwood.com/en/permalink/catalogue2134
Year of Publication
2017
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Floors
Author
Ljunggren, Fredrik
Simmons, Christian
Öqvist, Rikard
Publisher
Elsevier
Year of Publication
2017
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Impact Sound Insulation
Low Frequency
Lightweight
Footstep Annoyance
Subjective Perception
Single Number Quantity
Research Status
Complete
Series
Applied Acoustics
Summary
A previous Swedish research project indicated the potential need for evaluating impact sound insulation from 20 Hz in buildings with lightweight constructions. This is a discrepancy compared to the commonly used frequency intervals starting from 50 or 100 Hz. The statistical significance of this groundbreaking suggestion was however not satisfactorily strong since the result was based upon a limited number of building objects. The scope of the present paper is to secure the previous study by adding additional objects to the underlying database, thereby increasing the confidence of the results. The methodology is to perform impact sound insulation measurements in apartment buildings of various construction types and to perform questionnaire surveys among the residents. The measured sound insulation is compared to the subjective rating by the occupants in order to find the parameter giving the highest correlation with respect to frequency range and weighting. The highest correlation was found when the impact sound insulation was evaluated from 25 Hz using a flat frequency-weighting factor. Frequencies below 50 Hz are of great importance when evaluating impact sound insulation in lightweight constructions.
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Development of Robust Design Details for Improved Acoustics in Mass Timber Construction

https://research.thinkwood.com/en/permalink/catalogue2249
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Organization
Université du Québec à Chicoutimi
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Model
Airborne Sound Transmission
Impact Sound Transmission
Research Status
In Progress
Notes
Project contact is Sylvain Ménard at Université du Québec à Chicoutimi
Summary
To ensure the acoustic performance of wood constructions, the research group at the Sustainable Building Institute at Napier University has established a series of proven solutions. The advantage of this approach is to provide designers with solutions that have been technically validated, thus allowing them to overcome the burden of proposing to the manufacturer an acoustic solution. The tools to develop this concept will involve an understanding of the propagation of impact and airborne noises in the main CLT building design typologies, validating the main solutions through laboratory testing and providing proven solutions. Many NRC (National Research Council of Canada) trials could have been avoided. Conducting tests is expensive, and it would be interesting to link the test results to the modeling results.
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Finite Element Modeling for Vibration Transmission in a Cross Laminated Timber Structure

https://research.thinkwood.com/en/permalink/catalogue1633
Year of Publication
2016
Topic
Acoustics and Vibration
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Vardaxis, Nikolaos-Georgios
Hagberg, Klas
Bard, Delphine
Year of Publication
2016
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Acoustics and Vibration
Keywords
Sweden
Numerical Model
Finite Element Model
Impact Noise Transmission
Impact Sound
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 2953-2962
Summary
This paper deals with a certain type of C.L.T. (Cross Laminated Timber) construction, in a residential building in Fristad, Sweden. The objective is to study impact noise transmission, at the lower frequency range (10-200 Hz), where wooden dwellings perform inefficiently, in terms of acoustic quality. The vibrational behavior of lightweight structures and specifically a multilayered floor separating two vertically adjacent bedrooms are investigated. A numerical model of the multilayered test plate, which includes sound insulation and vibration isolation layers, is developed using the Finite Element Method (F.E.M.) in commercial software. The design process, the analysis and improvement of the calculated outcome concerning accuracy and complexity are of interest. In situ vibration measurements were also performed so as to evaluate the structures dynamic behavior in reality and consequently the validity of the modelled results. The whole process from design to evaluation is discussed thoroughly, where uncertainties of the complex F.E.M. model and the approximations of the real structure are analyzed. Numerical comparisons are presented including mechanical mobility and impact noise transmission results. The overall aim is to set up a template of calculations that can be used as a prediction tool in the future by the industry and researchers.
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Fire Resistance of Timber Framed Floor with Isolated Ceiling Assembly

https://research.thinkwood.com/en/permalink/catalogue685
Year of Publication
2014
Topic
Acoustics and Vibration
Fire
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Ceilings
Author
Park, Joo-Saeng
Lee, Sang-Joon
Yeo, In-Hwan
Year of Publication
2014
Format
Conference Paper
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Ceilings
Topic
Acoustics and Vibration
Fire
Keywords
Heavy Impact Sound
Fire Resistance
Sound Insulation
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 10-14, 2014, Quebec City, Canada
Summary
Fire resistance test was performed for a floor assembly, of which stiffness was reinforced by shortening the span of floor joists by adding glulam beam in the middle of the original span, and which an additional ceiling component was installed apart from floor part. These factors are expected to show good insulation performance of timber framed floor against heavy impact sound. From full scale fire test, it is conclude that the designed and manufactured floor achieved 1 hour of fire resistance rating.
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Guide to Calculating Airborne Sound Transmission in Buildings: Fifth Edition, December 2019

https://research.thinkwood.com/en/permalink/catalogue2617
Year of Publication
2019
Topic
Acoustics and Vibration
Design and Systems
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Floors
Walls
Author
Hoeller, Christoph
Quirt, David
Mahn, Jeffrey
Müller-Trapet, Markus
Organization
National Research Council of Canada. Construction
Publisher
National Research Council of Canada. Construction
Year of Publication
2019
Format
Book/Guide
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Floors
Walls
Topic
Acoustics and Vibration
Design and Systems
Keywords
Apparent Sound Transmission Class
Sound Insulation
Sound Transmission
Concrete
Building Code
Impact Sound
Research Status
Complete
Summary
In recent years, the science and engineering for controlling sound transmission in buildings have shifted from a focus on individual assemblies such as walls or floors, to a focus on performance of the complete system. Standardized procedures for calculating the overall transmission, combined with standardized measurements to characterize sub-assemblies, provide much better prediction of sound transmission between adjacent indoor spaces. The International Standards Organization (ISO) has published a calculation method, ISO 15712-1 that uses laboratory test data for sub-assemblies such as walls and floors as inputs for a detailed procedure to calculate the expected sound transmission between adjacent rooms in a building. This standard works very well for some types of construction, but to use it in a North American context one must overcome two obstacles – incompatibility with the ASTM standards used by our construction industry, and low accuracy of its predictions for lightweight wood or steel frame construction. To bypass limitations of ISO 15712-1, this Guide explains how to merge ASTM and ISO test data in the ISO calculation procedure, and provides recommendations for applying extended measurement and calculation procedures for specific common types of construction. This Guide was developed in a project established by the National Research Council of Canada to support the transition of construction industry practice to using apparent sound transmission class (ASTC) for sound control objectives in the National Building Code of Canada (NBCC). However, the potential range of application goes beyond the minimum requirements of the NBCC – the Guide also facilitates design to provide enhanced sound insulation, and should be generally applicable to construction in both Canada and the USA. This publication contains a limited set of examples for several types of construction, to provide an introduction and overview of the ASTC calculation procedure. Additional examples and measurement data can be found in the companion documents to this Guide, namely NRC Research Reports RR-333 to RR-337. Furthermore, the calculation procedure outlined and illustrated in this Guide is also used by the software web application soundPATHS, which is available for free on the website of the National Research Council of Canada (see the references in Section 7 of this Guide for access details).
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Impedance Characteristics in Wooden Frames Structure Using Large Dimension Glued Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue994
Year of Publication
2013
Topic
Acoustics and Vibration
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Author
Yoda, Takuya
Inoue, Katsuo
Tomita, Ryuta
Okura, Yasuhiko
Organization
Architectural Institute of Japan
Year of Publication
2013
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Floors
Topic
Acoustics and Vibration
Keywords
Impact Sound
Research Status
Complete
Summary
Recent years have witnessed an increased use of glued timber products in construction, due to their highlights in versatility and sustainability. It is therefore a demanding necessity to develop non-destructive integrity assessment methods for structural health monitoring of timber constructions, both during production and utilization. Particularly, the integrity and load bearing capacity of the glue line need to be tested. Air coupled ultrasound (ACU) is a novel non-destructive method which is well suited for this purpose. The advantages with respect to traditional ultrasonic contact techniques are phenomenal reproducibility and unlimited scanning capabilities, together with full preservation of the properties of the inspected object. As part of an on-going project in the Swiss Federal Laboratories for Materials Testing and Research (Empa) together with the Laboratory for Wood Physics and Non-Destructive Testing Methods of ETH Zuerich, experiments were performed in samples consisting of two layers of glued laminated timber with artificially introduced delaminations. First, the main ultrasound propagation phenomena were modelled with dedicated analytical calculations and numerical simulations. Next the samples were scanned with a precise mechanical system and a Normal Transmission Mode setup and the ACU waveforms were digitized for each scanned position. A specific amplitude tracking algorithm together with a self-calibration procedure applied to the ultrasonic images were used to compensate for ultrasonic amplitude variations induced by wood heterogeneity. The mean amplitude variations in the orthotropic R-T plane and in the L axis were of 10 and 5 dB respectively. After an appropriate wood heterogeneity correction the uncertainty in the R-T plane was reduced down to 4 dB. Adhesion defects were reliably assessed for the investigated samples, as well in situations where adhesive was present in the glue line but no bonding existed between timber lamellas (dry glue), or where the adhesive spread during the pressing in an uncontrolled way to the desired non-glued regions. The ACU results were validated with an also novel Micro Focus Computed Tomography glue line assessment method. Specific wave propagation phenomena depending on the year ring orientation with respect to the insonification direction were also discussed.
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16 records – page 1 of 2.