ASTM E1042-02 (R2021) pdf free download.Standard Classification for Acoustically Absorptive Materials Applied by Trowel or Spray.
1.1 This classification covers materials applied by trowel or spray to surfaces for the purpose of increasing their acoustical absorption.
1 .2 The values stated in SI units arc to be regarded as standard. No other units of measurement are included in this standard.
3. 1 .2 Sound absorplion average (SAA)—a single number rating, the average, rounded off to the nearest 0.01, of the sound absorption coefficients of a material for the twelve one-third octave bands from 200 through 25(X) Hz, inclusive, measured according to Test Method C423.
4. 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.
5. Basis of Classification
5. 1 Classification is made according to type of material, acoustical properties, flame spread, and dust propensity.
5.2 Material Type—Classification of acoustically absorptive material according to material type is as follows:
5.2.1 Type I—Material is cementitious. Type I ingredients shall he uniformly mixed and ready for use by the addition of water. When received, the material in the container shall be dry and shall not be caked or sticky. After the material has been properly mixed with the amount of water specified by the manufacturer, the material shall he of such a consistency that it can be applied with a plastering trowel or with a suitable plaster-spraying machine.
5.2.2 Type II, Material is fibrous. Type II material shall consist of mineral or organic fiber with an integrally mixed hinder, or it may he supplied ftr use with a liquid binder added at the time of application.
5.2.3 Type III. Material is cellular plastic and is intended for application over beams, walls. ceilings, and columns. Type 111 materials arc normally designed to bc mixed at the time of application.
5.3 Noise Reduction coefficient—Classification of acoustically absorptive material according to its noise reduction coefficient (NRC) shall be as follows.ASTM E1042 pdf download.