ASTM_E_1123_-_86_2009.pdf

Designation:E112386(Reapproved 2009)Standard Practices forMounting Test Specimens for Sound Transmission LossTesting of Naval and Marine Ship Bulkhead TreatmentMaterials1This standard is issued under the fixed designation E1123;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These practices describe test specimen mountings to beused for naval and marine ship applications during soundtransmission loss tests performed in accordance with TestMethod E90.1.2 The structure specified in these practices is intended formounting of single-layer treatments or composite treatmentsconsisting of various materials and configurations.Acousticaltreatment materials may be combinations of acoustical absor-bent materials,limp mass septums,and insulation materials.1.3 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C634 Terminology Relating to Building and EnvironmentalAcousticsE90 Test Method for Laboratory Measurement of AirborneSound Transmission Loss of Building Partitions andElements3.Significance and Use3.1 The sound transmission loss provided by a material thatcovers a flat surface depends not only on the physical proper-ties of the material but also on the type of structure to which itis mounted and the mounting method used.3.2 Naval and marine architects and design engineers re-quire specific transmission loss characteristics of acousticaltreatment materials as they would exhibit installed on a shipsstructure.The mounting structure and procedures specified inthese practices are intended to simulate such a shipboardenvironment.3.3 Test reports may refer to this mounting by PracticesE1123 instead of providing a detailed description of themounting used.4.Mounting Structure and Methods4.1 The mounting structure consists of a fabricated alumi-num bulkhead.This bulkhead is designed to fit within a 2.44-m(8-ft)opening in the filler walls between the reverberationrooms of a test facility.Test result measurements due to theeffects of the filler walls may be accounted for as specified inTest Method E90.A larger mounting structure may be used ifit can be demonstrated that this structure yields results com-parable to the 2.44 by 2.44-m(8 by 8-ft)mounting structure.4.1.1 The bulkhead is fabricated in two sections,1.22 by2.44 m(4 by 8 ft)and is fastened together by a 10.2 by 10.2 by10.2-cm(4 by 4 by 4-in.)aluminum I-beam.4.1.2 The coupling is accomplished by using 8-mm(516-in.)SAE grade B steel stove bolts,torqued to 3.33 m/kg(25 ft/lb).4.1.3 The 6.4-mm(14-in.)sheet aluminum panels,1.22 by2.44 m(4 by 8 ft),are supported with 10.2 by 10.2 cm(4 by4 in.),2.976-kg per linear metre(2-lb per linear ft)tee beams.4.1.3.1 The tee beams are welded to the 6.4-mm(14-in.)aluminum sheets with welds on either side of the centermember of the tee at 53.3-cm(21-in.)intervals.4.1.3.2 Weld areas should be approximately 7.6 cm(3 in.)long.Welding in excess of these intervals may cause severewarpage of the bulkhead.The tee beams are positioned on thealuminum sheets to obtain a distance of 61 cm(2 ft)betweentee beam centers with the I-beam serving as the bulkheadcenter support.4.1.4 Fig.1 illustrates the construction details.The bulkheadshall be installed with the smooth side facing the acousticalsource room and fastened in the filler wall opening by anymeans which will provide a secure,rigid structure.Taperedwooden wedges driven between the filler wall at each tee beam1These practices are under the jurisdiction of ASTM Committee E33 onBuilding and Environmental Acoustics and are the direct responsibility of Subcom-mittee E33.03 on Sound Transmission.Current edition approved April 1,2009.Published August 2009.Originallyapproved in 1986.Last previous edition approved in 1998 as E1123 86(2003).2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 support will provide the necessary rigidity.Acoustical sealantshall be applied around the bulkhead edges,between the fillerwall and the bulkhead and the I-beam panel connector toensure an airtight seal.This seal should be confirmed byenergizing the acoustical source and listening for spuriousnoise