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ASTM E1042-02

(Classification)

Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray

Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray

SCOPE
1.1 This classification covers materials applied by trowel or spray to surfaces for the purpose of increasing their acoustical absorption.

General Information

Status
Historical
Publication Date
09-Oct-2002
ICS
91.120.20 - Acoustics in building. Sound insulation
Technical Committee
E33 - Building and Environmental Acoustics
Drafting Committee
E33.04 - Application of Acoustical Materials and Systems
Current Stage
Ref Project

Relations

Replaces
ASTM E1042-92(1997)e1 - Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray
Effective Date
10-Oct-2002
Replaced By
ASTM E1042-02(2008) - Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray
Effective Date
15-Mar-2008
Referred By
ASTM C634-22 - Standard Terminology Relating to Building and Environmental Acoustics
Effective Date
10-Oct-2002

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ASTM E1042-02 - Standard Classification for Acoustically Absorptive Materials Applied by Trowel or SprayASTM E1042-02 - Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray
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ASTM E1042-02 - Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray
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Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E 1042 – 02
Standard Classification for
Acoustically Absorptive Materials Applied by Trowel or
1
Spray
This standard is issued under the fixed designation E 1042; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 5. Basis of Classification
1.1 This classification covers materials applied by trowel or 5.1 Classification is made according to type of material,
spray to surfaces for the purpose of increasing their acoustical acoustical properties, flame spread, and dust propensity.
absorption. 5.2 Material Type—Classificationofacousticallyabsorptive
material according to material type is as follows:
2. Referenced Documents
5.2.1 Type I—Material is cementitious. Type I ingredients
2.1 ASTM Standards:
shall be uniformly mixed and ready for use by the addition of
C 423 Test Method for Sound Absorption and Sound Ab- water.When received, the material in the container shall be dry
2
sorption Coefficients by the Reverberation Room Method
and shall not be caked or sticky. After the material has been
2
C 634 Terminology Relating to Environmental Acoustics properly mixed with the amount of water specified by the
E 84 Test Method for Surface Burning Characteristics of
manufacturer, the material shall be of such a consistency that it
3
Building Materials can be applied with a plastering trowel or with a suitable
E 795 Practices for Mounting Test Specimens During
plaster-spraying machine.
2
Sound Absorption Tests 5.2.2 Type II, Material is fibrous. Type II material shall
E 859 Test Method for Air Erosion of Sprayed Fire-
consist of mineral or organic fiber with an integrally mixed
4
Resistive Materials Applied to Structural Members binder, or it may be supplied for use with a liquid binder added
at the time of application.
3. Terminology
5.2.3 Type III, Material is cellular plastic and is intended for
3.1 Definitions:
application over beams, walls, ceilings, and columns. Type III
3.1.1 The acoustical terminology used in this classification
materials are normally designed to be mixed at the time of
is consistent with Terminology C 634.
application.
3.1.2 Sound absorption average (SAA)—a single number
5.3 Noise Reduction Coeffıcient—Classification of acousti-
rating, the average, rounded off to the nearest 0.01, of the
cally absorptive material according to its noise reduction
sound absorption coefficients of a material for the twelve
coefficient (NRC) shall be as follows:
one-third octave bands from 200 through 2500 Hz, inclusive,
NRC Grade Designation Minimum Acceptable
NRC or SAA
measured according to C 423.
NRC 95 0.95
4. Significance and Use
NRC 90 0.90
NRC 85 0.85
4.1 Acoustically absorptive materials are used for the con-
NRC 80 0.80
trol of reverberation and echoes in rooms. This standard
NRC 75 0.75
provides a classification method for acoustically absorptive
NRC 70 0.70
NRC 65 0.65
materials applied directly to surfaces by trowel or by spray.
NRC 60 0.60
NRC 55 0.55
NRC 50 0.50
1
This classification is under the jurisdiction of ASTM Committee E33 on
NRC 45 0.45
EnvironmentalAcousticsandisthedirectresponsibilityofSubcommitteeE33.04on
NRC 40 0.40
Application of Acoustical Materials and Systems.
NRC low 0.00
Current edition approved Oct. 10, 2002. Published October 2002. Originally
e1 NOTE 1—Because sound absorption varies with product thickness,
published as E 1042 – 85. Last previous edition E 1042 – 92 (1997) .
2
information on the required thickness and measurement method for a
Annual Book of ASTM Standards, Vol 04.06.
3
particular grade must be supplied by the manufacturer.
Annual Book of ASTM Standards, Vol 04.07.
4
Annual Book of ASTM Standards, Vol 04.11. NOTE 2—Determine NRC or SAA values in accordance with 6.1.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E1042–02
NOTE 3—SinceSAAisreplacingNRC,SAAvaluesmaybeusedinlieu
5.5.1 Category A—Dust removed shall not exceed 0.27
2
2
of NRC when rating material according to this standard classification.
g/m (0.025 g/ft ) when tested in accordance with Test Method
However, the NRC nomenclature is retained as the classification label. It
E 859.
is recommended that ratings based on newly acquired absorption data use
2
5.5.2 Category B—Dust removed is greater than 0.27 g/m
SAA. Ratings based on data measured before Test Method C 423 required
2
(0.025 g/ft ) when tested in accordance with Test Method
SAAmay use NRC. See Test Method C 423 for more discus
...

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1.3 This test method prescribes a uniform procedure for reporting laboratory test data, that is, the normalized one-third octave band sound pressure levels transmitted by the floor-ceiling assembly due to the tapping machine.  
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1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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3.2.4.1 Discussion—The mandatory language of section 3.2.4 is consistent with the mandatory language from §E2 of Form and Style for ASTM Standards (April 2020) and with the ASTM Committee E33 bylaws in place when this standard was published; it reflects a situation that exists, it does not prescribe anything.  
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1.1 This terminology covers terms, related definitions, and descriptions of terms used or likely to be used in building and environmental acoustics standards. Definitions of terms are special-purpose definitions that are consistent with the standard definitions but are written to ensure that a specific building and environmental acoustics standard is properly understood and precisely interpreted. The primary focus of this document is upon terms, definitions and descriptions found within standards under the jurisdiction of ASTM Committee E33; however, terms, definitions and descriptions that are of general interest to the field of acoustics are also included.  
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5.1 The specific airflow resistance of an acoustical material is one of the properties that determine its sound-absorptive and sound-transmitting properties. Measurement of specific airflow resistance is useful during product development, for quality control during manufacture, and for specification purposes.  
5.2 Valid measurements are made only in the region of laminar airflow where, aside from random measurement errors, the airflow resistance (R = P/U) is constant. When the airflow is turbulent, the apparent airflow resistance increases with an increase of volume velocity and the term “airflow resistance” does not apply.  
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SCOPE
1.1 This test method covers the measurement of airflow resistance and the related measurements of specific airflow resistance and airflow resistivity of porous materials that can be used for the absorption and attenuation of sound. Materials cover a range from thick boards or blankets to thin mats, fabrics, papers, and screens. When the material is anisotropic, provision is made for measurements along different axes of the specimen.  
1.2 This test method is designed for the measurement of values of specific airflow resistance ranging from 100 to 10 000 mks rayls (Pa·s/m) with linear airflow velocities ranging from 0.5 mm/s to 50 mm/s and pressure differences across the specimen ranging from 0.1 Pa to 250 Pa. The upper limit of this range of linear airflow velocities is a point at which the airflow through most porous materials is in partial or complete transition from laminar to turbulent flow.  
1.3 A procedure for accrediting a laboratory for the purposes of this test method is given in Annex A1.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4.1 Table 1 is provided for user to convert into cgs units.    
cgs acoustic ohm  
mks acoustic ohm (Pa·s/m3)  
105  
cgs rayl  
mks rayl (Pa·s/m)  
10    
cgs rayl/cm  
mks rayl/m (Pa·s/m2)  
103  
cgs rayl/in.  
mks rayl/m (Pa·s/m2)  
394  
mks rayl/in.  
mks rayl/m (Pa·s/m2)  
39.4  
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5.1 The acoustical impedance properties of a sound absorptive material are related to its physical properties, such as airflow resistance, porosity, elasticity, and density. As such, the measurements described in this test method are useful in basic research and product development of sound absorptive materials.  
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5.3 Estimates of the random incidence or statistical absorption coefficients for materials can be obtained from normal incidence impedance data. For materials that are locally reacting, that is, without sound propagation inside the material parallel to its surface, statistical absorption coefficients can be estimated from specific normal acoustic impedance values using an expression derived by London (1).5 Locally reacting materials include those with high internal losses parallel with the surface such as porous or fibrous materials of high density or materials that are backed by partitioned cavities such as a honeycomb core. Formulas for estimating random incidence sound absorption properties for both locally and bulk-reacting materials, as well as for multilayer systems with and without air spaces have also been developed (2).
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1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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ASTM E1042-22(Classification)
Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray

SIGNIFICANCE AND USE
4.1 Acoustically absorptive materials are used for the control of reverberation and echoes in rooms. This standard provides a classification method for acoustically absorptive materials applied directly to surfaces by trowel or by spray.
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1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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1.3 This test method does not evaluate the overall acoustical environment. It is intended only to measure and report the masking sound levels.  
1.4 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.  
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