Document 3JGXbX1kvqL1ndXOk0M7rw8Gy

mmm tVam-ii i wiiM i LIA14317 o&a ..ibi Lead Indaslrleti AAffOcIation.Xnc. 9M MADtOON AVCNUC IW YORK. H. T. 10017 **tA mn na DWM D. MARTtM, JUA Ma a a * AacMinenMAi i ^V-w / ^ * * . ',f i - * . -: -<v < eo s j ic t i tennrr or a it ic l e ow a p p l ic a t io n or l e ap po m SOUKD 1NSULATIWC PArrmOMS TOi tabtri of the load Industrie* Association, Sac. Tba Load loduacrlaa Association ha* juat obtained a limited quantity of tho ancloaad reprint, "Application of Load for Sound Insulating Partitions." Tbit artlcla originally appaarad In tba May, 1967, laaua of S)V, a *! on sound and vibration. tasearch for tbla papar, by A.V. Malar, mi sponsored by tba International Load Zinc Eesaarch Organisation. Ha foal tba Information contained hero will fill a need for a somewhat mere technical reply to Inquiries from those whose j Interest*, as wall as knowledge, are more than preliminary la scop*. Additional copies of this reprint, In quantities up to twenty-five, will be available to our members, free of charge wfalla tba supply lasts. Vary truly yours. Edwin D. Martin, A.l.A. Manager, Architectural Services EZK/lhw Enclosure mp1 JH i*(JUii IMU m? in iii mu nil iiy,u ; litiii gi -- 11--,T "- -- LIA14316 i i APPLICATION OF LEAD FOR SOUND INSULATING PARTITIONS TV ) mm,, i y N 3509.01 I WgWf.'JMJJ LIA1A319 11 I ! 1`1'IBHpw APPLICATION OF LEAD FOR SOUND INSULATING PARTITIONS A. v. MIt ,* HInrich Hertz Irwtltut (or SchwtngunpforKhung, Berlin L*mI ke hr i Ww hie Ail TW Htbr Am here fI lad It* caapirttivtly low Young* wadulia, wm tXO X 10" dy-nm/cra1, gowUhiU mod Intnbb wabtoaUoa lor ipplkatioa of thb material fur MMtkml m. Plate* made (nn lead would hn^ Mi laavy *Nfh wd hmpneat, tf-- pwldhn a pearly him! wad Inaulninf pariirmanc*. la praetka, kownar, tbiwiof port load pbftm to k* practical, moetly for wnaornk eeaaona, but abo bawi a bad pwlitta would baw too low a tree* twal rigidity to comply with architectural dm awth. From aw eoonomte ai wQ w from a tarhwfcul pdot of view N to thavafec* of totereto to Inwtk gala bow to war bad mputofly 1 CMwbmartow witb other drapo and atiftcr m Moriah la aucb a way that the very ktgb aound-toeulabwg pdimwni of lewd add* to tha quahtba of cowwwhiral buildup malarial*. wh*h ar* prafarabla hi othar impact*. General guide* fc* tba enoetruetkm af aucb bad* omnbtoed panrh can be outlined. A few practical earnphi of typical pariitoaa ara daaerfbad with oorrwpuuding sound tndabtoi lorn data aa aaaa> aured to the laboratory. Ifcayle Udf PaiHHawa A* b waft ban, the aoowd toanWhm af a leaf partitoa depend* mainly aa two af lb L Ito wham h m thkfcneaa af pbtot awd 1. Ito (1) M -- --5-- X -- (I-V) u (*> TW nA> ti bredaif *1tnmi Is nrfn W f eauta pi* dCTlti tta > >!.< (rqaacy `-VS (*) Sbgbt ddocnoH Id usage awd technical prao bees Utwna acuuethal Hginiin to tba faded Stator and to Europe moat be anted for the sake of aaiitwraa and a full dawdmg of thk article. In the Vailed Stater, to to to talk about aound bolahoa rather than eomid toeulatcai Thia baa pw eto of afluupto to ediminitf coofusoa between popular firm tbrrwia] InauUbao and any added Bound bob too that aught orewr If It to uard to a waft, h b nut orerwarily ao, and on amt occadrmf the added thermal toeubtow blanket deertwa the aound toolrtvm. Another common term In the United State* b sheet of building material. Hb b irftried to aa pbto by thr author. Owe lari note relate* to the frequency range erf architectural totereat and the lowed eDow abb coiaidraci frequency la Europe, the accepted frequency range of architectural to* tored b 100 to 3900 c/a. In thr United State* and Canada, thr range b conudered to be IIS to 4000 c,'i Thb would require placing the minimum coincidence frequency at 4000 c/a ft the tdnddwf dip b not to affect the rroulto materially. -- 340*/me Wfthm a frrqoency rawge ap to aboat caw i below ib*> hmitmg frequency the aoawd toeabtfad caw be cmlrwiteed fairly accurately km tha am TL O () Jlw wundt / -- bequewey Z -- free irld cbwractertotic Imp*lilted It g ear4 see Eyetina 4 aa given bare b for a erf tocidrocw af 49*. Generally the mam law drnotea the ouad tneuhtioa rf a dwgle-lraf partMkm. be rmhard m)y wdhto the low frrqwecy whiienB lor higher fiequewcto* the difneaa act* the b u m Inertia nor* and more, thus the TL Mm* frequency curve to break awr the maaa bw hnr and to drop to a more or b aowncad mtodaian. tba wr04uwwa * Now to National fhydmt ft--well Lahentoiy, fteterta, tod Africa. mm ipnpp I mp LIA14320 ^tomtotortsiStts ifi u3to>MliiitoiitoRiiidMMc* irtu -c V" I- - - - - - 1 fp*> 1. C^prf fwm of ww Mm Imm (TL) ww freymwfr A* asm# mrfar* in Ii ^ M d#s*n <o Ac/* - u a/r* iwwto abM th* fimfftog In - Figure 1 tontting frv^nha a( plm taring dr une torInc* ueigto ifcct tbdr Round tawkiat. Owing to dr k*w hmftmg (coincsdrere) frequency of the fj'pnw pbtc, (ikm hare os i NpftwNPn apk tor --iry other buflAoj Mttrtih, the TL vaksee at medium hrqurftfwi are already twdJ mb))' tower than predicted by the imm law of Equation 4- It to therefore Impmaibh to Malta fuQ ** of the plate*! surface aught to obtain high sound toaulaUm within the Moat important medtua frequency nap. This efect ii even mure pre aounrrd whew thacier platea with greater furfaca weight art used, since tlw toaiting frequency b bivmdy proportional to plate thkkrwaa. a (oOwi from bwertMg Equation I and Equation 2 into Equation X Th* builting frequency of the lead plate in Figure 1 it, ea the contrary, high enough to fulfill the mam law up to frequencies far bryund the range of rchJiecturm] interest. Tito meant that at togL (re quancire the Bound tosulatkm of pure had fheat h bettor than necessary, aa far m inauUtiim from ordinary office, domestic, or trafic noise h concerned. Kefwring to th* previously Mated problem of cmbating had with a building Material, one c m now cumiude from Figure 1 Omt M shuukl be put* afbl* to shift the cotoctdence dip to any position fpar 1 fmfiir i htewii the two i iti emra dm to the figurenamely, toward higher frequenciea when the lead component dominate*, and toward lower frequencies when the content of budding material tn cream la between an optimum ntti where, on the one hand, the plate*! stiffness b aa high aa poniblr and, on the other hand, the Round inauUtiaa potential of tha had is fuDy utflued, but only at thoa* frequendo* where high TL value* are of practical value. Tito require* the limitinf frequency to bo aat at about - 3000 c/a. Accordingly, the highest pooftib TL vaViea that arc given by the mass law wfB be provided up to frequencies of about 1500 c/s--that to within dm moat important frequency range whereat, because of the stiffness influence, th* TL curve wfB level off at higher fraqumchw, os indicated to Figure I by the dotted hnr fur th* combined plat*. Hits behavior generally correspond* to th* shop* of the standard ountuun fur evaluating th* sound tiansmUakm class (STC) of a partition.1 Hi* entodma dip fmiM 10UN0 AND VllfiATlON fiagrmt 2 \ P'"u h mu w ummosmwwMrouprowm^qaaa^puroosammiro^^ LIA1432 i dMteibfcM ft-Virfft.!.bMtimaKUfe**.. i W slightly obove the hywiey mfi of ktaml to architectural acoustics. This optitotl kmiHn| (wqumcy determine* the optimal thkiw dimouicM of tod sheet aod butidmg plate to be combined with each other, whereby for fiveo total surface weight the weight of lead should be e minimum, jiMt sufficient to keep dw limiting frequency at f$ 9000 c/a The cafaubtioo of the lever ttobwon it bated oo tome typical sandwich constructions shown die* grammatically to Figure 1; Crnmetioe a Lead sheet rigidly adhered to torfldmg plate by uisani of e bard epoy rrrin Conwrortirm b. Lead sheet rigidly appbed at the neutral plane of building plate by the feme type of adhesive. Coufmetini t Lead sheet elastically applied to biiWmf plate by means of an elastomeric resin. Construction d. Lead sheet ckitkmOy appbed at the neutral plana of building pbtn. Construction o. Small lead tike adhered to buddtag plate (Brovundt construction) or Irad granules bonded with phenolic resin to base pleta. Ammung a halting frequency of 3000 c/s for aS thor constructions means that, according to Equa tion 3 the ratio sa/B usmlii constant Since the surface weight, at, a* weB as the bending stiffness, I, ill function ef the layer thkknemee. dependent on the different types of cocntnirtian. Equation 3 rr presents the grnsral dimenwial equetkai, and It now has to be determined bow m and I depend on the tlucLneas, hj, of building plate and on the thick* neases, h*. ef toed the^. The mrfece weight is afcnply given by the sum of the individual ompomwts; m "fA + (5) for al confltructkma. Oo the other hand, the heading stiffnem of the ComptuOf plate is a more coropbcatcd function, dependent not only on the layer thseknessee but ato on Young`i modulus E, of building material and Eg of lead, as weD as on the way to which both me* tarlab are combined. This con be written gmmlly to the km (6) where Bt Is given by Equatioo 1 Furthermore, the bendmg stiffness far oonstmc* No s h c and d with ckuticsDy adhered tod ilwti is sto a function of frequency. It Increase* at low frequrmbs, thus showing the favorable effect of providing higher stiffness against static loads than against dynamic acoustic nrttitioa In the latter cose the talua of the bending stiffness can be assumed, for the puspom of Ibis investigation, as being equal to its tanking value for blgb toqeaacto* Tbs determination of the hmetka of Equation I can be found to the lfterntur*;*-4 for Construction # the function of Equation 0 repreaauti a timpb special case, since the plate s holding stiffnees re main* unaffected by the adhmed email land pieces, and only the surface weight Is increased actsudtog to Equation S. AO other cnostructiocu require apnciffc evaluation of the function of Equation 6. Then, to cmlrUale the layer thirl news*, the functions of Equation 6 and Fquetion 5 ban to bo taaacted Into Equation 3 after aetting f0 m 3000 c/g This bes been enrried out far a ssbrHon flf fflBwm building matrrisb In wihtoshim wfcb lead. The meuks are ilium In tbe curvee of FlgmeS 3, 4. and 5, where tbe thickness ef lend dost, to pfatted againet fc,. tto thickness of bufkhng plain. Tbe surface weight, as tbe basic ftgure to asaem tba espetiad sound taaulation, to given as a parameter by assuming a ntnaniwn value far dm tbdben ef bad sheet. Fee practical spptaaShm ef them dspuH soma important mncluriowa can be drawn, There Is only a relatively vneB tup ef variation la b, (tUdsan of buildmg matrcisl) far an eftcient me of the appbed lead sheet On the ether bend, tbe thiihasm, h of the bed can be varied widely, practicaly fmm about 0.2 mm up to 6 mm. wberrby the applh cation of thicker bad sheets auks to gw elm surface UTsghti and to currrepoximgly bttar aosmd teeuto* tion. FethcneiR, by cumparing the cu~vu off ton ddmU sandwich tuneiiuLluen. cusntruction d a^ pears as tbe most favorable with regard to a taw ratio of weight of bed to weight of buildmf material TV diagrams abo allow a rough retini ale to bo made of byer tincknessea far seadwk&es using other buildmg materiab than thorn selected bn, pro* tided that the vahaa Et and pi bwhcaied on each of tbe diagrams are appmsanatrly equal to them of the material under msdatiiia Tbe diagrams of Figures 0 end T few raaubs of TL measurement* on paneb designed aooordteg feo curve e of Figure 3 and curve d of Figure S, re* qMvtively. They cun&na tbe rrpected aoimd taaubt* tig behavior--that fc, validity of the maos law aft taw and medium frequencies, decreasing slope at Irfghar frequencies, and the cotickWuce dip fate above too frequency range of practical Interval. The some pro* eral frequency wepunse Is observed fur al Othar sandwich ccmstructions. A variation to surface weight merely reauks la a vertical shtft of the whole JX curve. Hence II folbwi that a dr&nfte relation c m be found between tbe surface weight of the penel and its sound tismmiwiim dam.1 The latter to abo determined by e parallel shifting ef a frequency 4 pi^pqpiiuiiiwwffp^l wrnmmmmmm LIA1A 322 iJ I pp' iLiii'wi".^ ii ...f1 '"^w'lWwsiiEWMpriwmipisPiigi^ ...................mmmmmBrnm* L IA1432 3 W*4=_fc la-- w* 1 1 m m IIUW 1____ _____ Flgw 0. Tt nww frv*rmc9 mw for a IsaMant ^^MMPMimirrtM.'!0'(9Ofr). f||w 7. ft WKW* frfmtrt ATM far * lasdMesitawW piste. owtm<rioa d. Tmt was.- 9 m* (90 ftX 7i|*v f. TI www fraqanwp fw a d--Meh^ M r m 4 * po tf). src a Mtsd ptnek of die type shown In Figure & Pot i Soul nrfacs weight of 43 kg/m* the naf tnnamission clus obtained amounts lo 53. However, this remarkable result to ettmnely sensitive lo sound bndfei, at ore ofi conventional foebUnf peti tton. On the other bond, eertih raanher of rigid cooMctkiM between (he two teavet or* InovftiMs hr strechnl reasons and often mast deakabla for Am* framing the rigidity of r pmtitkm. The o h of lead sheets without stiffening 1 tk praeNi a unique pmrihltly to oonstniet doubls leaf partitions that ore very jnsrnritlvi lo sound bridges of any kind. It con be shown that, became of Its eacepttonally low stiffnm tu weight nth, an unlmnlnatrd had sheet has very poor aouathraihahag properties, became the radiated sound power Is directly proportional to the ratio B/m, when a plats is art Into Wbrabon by, for esample, a single point cuiiatksL If the sound bridges la a doublo waB an considered as such point endtatiwi sources, k can be aapccted that the Sound power radiated Into the receiving roosa wilt be very low, ff at least one leaf of He partition is a lead sheet This means that tha snsip portion that bypanes the double-leaf barrier via the sound bridges Is nearly negligible, and that the tnasninka has of the partition remains unim paired.' This unique property of a had shast In comparison with other metals is dearly brought out when ons consider! tha fact that tha ratio 0/a of a muim 9n0a^iiMRi|iiivr.:i"i mi i I '' *a ; LIA1432A i p 3 NfMaqrJ FlfW* |. I^hww if sound bridge* m i (m iffei diMelad cemnvbbn r* c t m. la'lion Fiw iO. TL mmtmt fmwwy mw fir a JmU> leaf nMnrtwi if Mgk brucSnraf ric*dftg> fli mb $ f fr> nc - . tod sheet b about thirty tones as groat m that of a lead sheet d the same weight An experimental proof of tine couderatioai b given In Figure 9. which ihowi the TL curve* far i double wall, me baf of which h a had sheet Connected to the other Id by a definite number of sound bndjert. A deterioration of the sound insolation becomes nohre able only when the number of sound bridges exceeds 30 per square meter (3 per square foot). Even whew the lumber of bridges b biercased to ISO per square meter (IS per square foot), the sound laoiilntiua still remains higher than for a single-leaf partition of the seme weight, for which validity of the mass tow b aimed. On the hasb of these findings, Greener* suggested a practical double-leaf construction shown diagram* utKaSy la t'igure 10 together with Its TL curve. Like the construction of Figure 9, me leaf cf this panel consists of a lead sheet without stiffening kmitutiaa The other leaf b a comparatively stiff wooden plate. Both torn are adhebvely applied ante the rough surface of a porous and stiff core ma lm*! which thus simultaneously provides a great number of stiffening rigid connect*** hetweew the outer skins (that b, sound bridges) and the acces sary ab cusbioa given by the pomtity of the coca material The measured TL curve yields a STC of 46, com plying with the requirements fur a good sound* taaulating office partition. The application of this panel construction far doors seems especially premis ing because of its conaktorablo structural rigidity. AtbseMpamb I wbh to thank Prof. L Cramar far many valuable igjfwwn md dbrumfans and the laiaraatkinal Lead Zinc Research Organiiatiun, New York, lor fit financial ipmunkip. Thb article was origin*fly published la the journal U'emtr Aalto ScAnfl. The publishers, Crunxwrif A Hartmann Ag Lndwipkaht, gave kmd permbrion for repubhshing thb authorised tranrtotion. fiefstsacw 1. ASTM Tbbto Hirmaieikf Practice to fis Mumwb of Air-fionw Sewed Trmmtoboe Lem sff Ru&faag Hoon and Walk. Ref. ISMl T. 1 C. Koto, FhptA 14 hrhft drv Mmelilbg fun*, pp 10341. fiarhmhr, 1964. 3 H Obml awl E. FmbWtU, AkmL Mk, g. Mi (I9S1-U). 4. E. M. !(< *. F. E. li and D Rom Sumd Dmmptmg {). E Rnckka, ed.), ASWE Reports, gp. 49C. New York. 1969 5. L Ciw, Dir a bum ka/dhtoa Cndbgm dsr RonehMrtk, Vei 3, pp Ufiff. Lactic. 1990. ft C Harrb, NeJiml of VoW ComtroL Chapkr IQ, pp. Hi. McOiw-HtQ Rook Company, Nrw York, 1997. 7. M Hrckl, "TntusmliyngiB von SchaObrikken bel Doiprhtmhi,* Report for the BustonWl fir Wohmmgthau No. 46 (1999). 6. A. v. Mrrt, 5th International Cengreee Are-- tka. L*gr. lues. P*per F3L 9. L Cmr aid A. v. Mbi*. "Application of lead for acoubkal nr In buildinf ptfttkM," Final Repast, leurwnmj l^nd Zmr Riwerth Orgsntaatioa, New York, 1969. SOUNO AND VIMATION Repnre 7 I LIA 1432 5 a \ $ %