HomeMy WebLinkAboutFile Documents.209 E Bleeker St.0320.2017 (157).ARBKRESEARCH AND DEVELOPMENT BULLETIN RD066
Sound Transmission Loss
Through Concrete and
Concrete Masonry Walls
by Albert Litvin and Harold W. Belliston
Rcpnnlrd wth perrmsston from the Journalofrhr Amrr~uu~ Conrrrrr lnrrrrurr.
No. 12, Proceedings Vol. 75, December 197X
PORTLAND CEMENT ASSOCIATION
Research and Development / Construction Technology Laboratories
Sound Transmission
Loss Through Concrete
and Concrete Masonry
Walls
by Albert Litvin and Harold W.Belliston’
H BUILDINGCODESAND GOVERNMENTALagencies
have,for many years,set limits on the amount of
noise that can be transmitted through building
components from one space to another.1-4tIn recent
years,there has been a greater awareness of the
adverse effects of excess noise on personal health
and comfort,work efficiency,and privacy.Con-
sequently methods of obtaining increased sound
insulation in buildings are needed.
The efficiency of a wall in restricting the
passage of airborne sound is measured in the
laboratory using the procedure outlined in “Lab-
oratory Measurement of Airborne Sound Trans-
mission Loss of B u i 1d i n g Partitions”(ASTM
E 90).5 Measurements are made of sound transmis-
sion loss (STL)in decibels (db)for a series of
frequencies ranging from 125 to 4000 Hz.
“Determination of Sound Transmission Class”
(ASTM E 413)8 describes a method for using the
transmission loss values,determined as above,to
arrive at a single figure rating for comparing the
effectiveness of walls in resisting the transmission
of airborne sound.This is defined as the sound
transmission class (STC).It is determined by fit-
ting the proper STC contour (ASTM E 413)to the
plot of sound transmission loss vs frequency
(ASTM E 90).The STC is then equal to the trans-
mission loss at 500 Hz.
A number of factors affect sound transmission
loss through walls.Weight per sq ft (mass)of the
wall has a major effect,and is sometimes used as
*Principal construction consultant and former construction engineer,
respectively,Construction Methods Section,Portland Cement Associ-
ation.
T Superscript nu,mbers that are not part of measurements designate ref-
erences at the end of this report.
a guide for determining transmission loss.The
“mass law”indicates that transmission loss should
increase 6 db when either the weight or the
frequency is doubled.
Other factors that affect sound deadening char-
acteristics are stiffness of the wall and presence
of resonant and coincident frequencies.Because of
overlapping of the effects of the various factors
involved,it is difficult to determine by analysis
the transmission loss of a particular panel.Most
designs,therefore,rely on STC values determined
in the laboratory.
Most housing codes require minimum STC val-
ues of about 45 for partitions where living units
adjoin other living units.Values of about 50 are
required where living units adjoin public spaces
or service areas.The mass and stiffness of concrete
and concrete masonry walls generally put them
in a range where they have little trouble meeting
present day STC requirements.
Tests reported in this paper provide STC values
for commonly used concrete and concrete masonry
walls and on walls that were upgraded to improve
their sound transmission properties.For conven-
ience in selecting walls for specific applications
and STC requirements,selected STC values ob-
tained by others on a variety of wail types are
included in this report.
TEST PROGRAM
Specimens
Three basic concrete wall specimens were fabri-
cated for these tests.Two were cast-in-place con-
crete and the third was concrete masonry.
Structural concrete panels,14 ft,4 in,(4,37 m)
wide by 9 ft,4 in.(2.84 m)high,were cast in
thicknesses of 6 and 8 in,(152 and 203 mm).An
air-entrained,sand and gravel concrete,repre-
sentative of wall construction,was used.Concrete
strengths at 28 days were 5610 and 4580 psi (38.7
and 31.6 MPa)for the 6 and 8 in.(152 and 203 mm)
thick panels,respectively,Corresponding unit
weights of the fresh concretes were 145 and 142
pcf (2323 and 2275 kg/m3).The panels were cured
for a minimum of 28 days before sound transmis-
sion loss tests were started.In addition to tests on
the bare concrete panels,wall finishing materials
were added to permit determination of their effect
on sound transmission.
A masonry wall,14 ft (4.26 m)wide by 9 ft
(2.74 m)high,was constructed using nominal
2 Sound Transmission Loss 7hrough Concrete and Concrete Masonry Walls
TABLE l—SOUND TRANSMISSION CLASS (STC)-PCA TESTS
Constructionof wallsTestDescriptionofwall 4fppro:
wall
weight,
psf
71.0
fleasured
STC
57
59
62
63
No.
I Side 1 Side 2
6 in.cast concrete walls
76-66
76-68
76-69
76-70
76-71
Plain Plain
Plain “Z”furring channelsplu
%in.gypsum board
72,5
Plain “Z”furring channelsPIU
1 in,6 pcf rockwool plus
%in.gypsum board
75.5
vertlcmy,24“OC.‘ackw””’‘“’’h’d
~x 2 in.wood furring
?lUS1%in.4 pcf rock-
wool plus ?4 in.gypsum
~oard
78.5“Z”furring plus 1 in.
B pcf rockwool plus %in
gypsumboard
2X2,
:;:\#Y,
V2°.qYmimn
wollkard
24”0,C,,Ockwool
?lain 2 x 2 wood furring plus
1%in,4 pcf rockwool
plus %in.gypsum board
73,0
96.6
101.6
63
58
——
59
/IV;,4 pcf ,Ock.wcol
2 “2,
VWtlcolly,
24”O.c.
8 in.cast concrete walls
?lain
76-77 Plain
,?”Chormels,bwti.xl!y,24”O,C /92”annum76-78 “Z”furring plus 1 in.
8 pcf rockwool plus %
in.gypsum board
!x 2 in.wood furring
)lUS ?4 in.gypsum board
\2x2 ,W,!lcally,\V,-gyp,.m wol(bowd
24”O.C
PCA Research and Development Bulletin 3
TABLE 1 fCont.140UND TRANSMISSION CLASS (STC)-PCA TESTS,,
Description of wall
Test
No,Side 1 Side 2
kpprox
imate
wall
weight,
paf
&easured
STCConstructionofwalls
I
8 in.cast concrete walls
97.0 59
Plain 2 x 2 in.wood furring
PIUS %in.gypsum boi
76-79
\2x 2,Wrticolly,11~~~gyp,,m
2.?”O.c.wllb.m,d
Plain 2 x 2 in,wood furring
plus 1%.in.4 pcf rock
wool plus %in,gypsu
board
76-99 97.2 63
I
I8in.lightweight concrete block walls
32.0 44
PlainPlain
Plain
76-7[
76-7(
76-7S
76-73
76-74
76-
104
2 coats acrylic latex
paint
32.0
35.0
48
59
\2 costsIofex point
1 in.air space plus 1%Plain
metal runner with stu
with 1%in,4 pcf rock
wool plus %in,gypsu
board
38,0
89.0
57
58
1 x 2 in,furring at 16:
plus %in.gypsum boi
2 x 2 in.wood furring
vertically at 24 in.plus
resilient channels hori-
zontally at 18 in.plus 1 ?4
in.4 pcf rockwool plus
%in.gypsum board
/I k’.4 M rockwool
2 x 2 in.wood furring
vertically at 24 in.plus
resilient channels hori-
zontally at 18 in.plus 1 ?4
n,4 pcf rockwool plus
%in.gypsum board
2ores of block grouted,
)ainted
Plain
Ily,
Cores of block groute(
plain 56
4 Sound Transmission Loss 7hrough Concrete and Concrete Masonry Walls
Refer-
ence
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
9
9
9
9
TABLE 2—STC VALUES REPORTED IN THE LITERATURE FOR WALLS
Description of wall
4 x 8 x 16 in.concrete masonry units,both sides plain
4 x 8 x 16 in.concrete masonry units,both sides plain
4 x 8 x 16 in.concrete masonry units,both sides painted
4 x 8 x 16 in.concrete masonry units,both sides %in.plaster
4 x 8 x 16 in.concrete masonry units,both sides %in.plaster
4 x 8 x 16 h.concrete masonry units,both sides %in.gypsum wallboard
4 x 8 x 16 in.concrete masonry units,both sides %in.gypsum wallboard
6 x 8 x 16 in.concrete masonry units,both sides plain
6 x 8 x 16 in.concrete masonry units,both sides painted
6 x 8 x 16 in.concrete masonry units,both sides painted
6 x 8 x 16 in.concrete masonry units,both sides ?4 in.plaster
6 x 8 x 16 in.concrete masonry units,both sides 72 in.plaster
6 x 8 x 16 in.concrete masonry units,both sides %in.gypsum wallboard
6 x 8 x 16 in,concrete masonry units,one side $4 in.gypsum wallboard,other
side painted
8 x 8 x 16 in.concrete masonry units,both sides plain
8 x 8 x 16 in.concrete masonry units,both sides plain
8 x 8 x 16 in.concrete masonry units,both sides painted
8 x 8 x 16 in.concrete masonry units,both sides painted,cores grouted and
reinforced
8 x 8 x 16 in,concrete masonry units,one side plaster,other side plain
8 x 8 x 16 in.concrete masonry units,both sides plaster
8 x 8 x 16 in.concrete masonry units,both sides plaster,cores grouted and
reinforced
Composite wall,4 in,brick,4 in,concrete masonry units,block side plaster
8 x 8 x 16 in.concrete masonry units,one side $+in.gypsum wallboard
8 x 8 x 16 in.concrete masonry units,both sides +!!in.gypsum wallboard,cores
grouted and reinforced
Composite wall,4 in.brick,4 in.concrete masonry units,%in.gypsum wall
board on block side
9 in,brick wall,both sides %in.plaster
Double wall of 4%in.brick leaves separated by 2 in.air cavity,no ties,?kz in.
plaster on exposed surfaces
4 x 8 x 16 in.concrete masonry units,both sides ye in.sanded gypsum plaster
6 in,thick cast concrete,both sides %in,plaster
—
Wall
weight,
psf
18
2’7
22
30
42
26
32
21
28
39
31
54
35
27
30
53
30
73
38
67
79
61
40
77
60
100
100
36
80
Reported
S!rc
40
45
43
48
50
47
48
44
46
48
46
52
49
53
45
52
46
55
52
56
56
53
56
60
56
52
54
46
53
8 x 8 x 16 in.(203 x 203 x 406 mm)lightweight Test procedure
concrete masonry units.The units were laid using
ASTM C 270 Type N7 masonry cement mortar.
The mortar joints were 3A in.(10 mm)high and
were tooled on both sides of the wall.After the
wall was assembled,sound transmission loss tests
were made on the bare wall.Next,wall finishing
materials were added and the tests were repeated.
The test walls and details of the surface varia-
tions are listed in Table 1.
Sound transmission loss measurements were
made by the Riverbank Acoustical Laboratories
following procedures outlined in ASTM E 90-75.
Measurements were made using a one-third octave
band of “pink”noise from 100 to 5000 Hz,as
recommended in ASTM E 90-75.The sound trans-
mission values were tabulated at 18 specified
standard frequencies.All STC values were com-
puted in accordance with ASTM E 413-73,
PCA Research and Development Bulletin 5
Each of the three walls was tested without any
surface treatment.Tests were next made on the
walls to determine the effect of additions to the
wall surfaces.Gypsum wallboard,acoustical in-
sulation,paint,and resilient fastenings were
added.
TEST RESULTS
PCA tests
The tests are summarized in Table 1.As indi-
cated in Table 1,bare concrete and concrete ma-
sonry walls commonly meet current STC require-
ments of 45 to 50 for buildings,However,to pro-
vide data needed to obtain higher STC values,
concrete walls were acoustically upgraded to de-
termine values that could reasonably be achieved.
The tests indicate that STC values in excess of
those obtained would be difficult and costly to
achieve.Consequently,requirements for higher
values would significantly increase the cost of
construction.
With the addition of wall finishes,sound trans-
mission class values up to 63 were obtained on
both the 6 and 8 in,(152 and 203 mm)cast con-
crete walls.It should be noted that the 6 and 8 in.
(152 and 203 mm)plain walls had STC values of
57 and 58,respectively.These are considerably
higher than most current code requirements.
The plain masonry wall had an STC of 44.Most
of the normal wall finishing techniques provided
STC values that significantly exceeded present
day require men ts.Even application of paint
brought the masonry wall above the minimum
requirement of 45.The grouted wall with one side
painted had an STC of 56,very close to that of the
cast concrete walls.Based on the increase in STC
obtained by the addition of furring,gypsum wall-
board,and acoustic insulation,it is apparent that
the addition of these materials to the grouted wall
would have resulted in an STC of 60 or greater.
Tests by others
Sound transmission measurements have been
made on a wide variety of wall constructions.The
STC values obtained from these measurements
have appeared in the literature or been reported
by governmental agencies,trade associations,and
private companies.Table 2 lists STC values for
a variety of wall types as reported by some of the
above sources,
SUMMARY
Concrete and concrete masonry walls generally
meet minimum STC requirements for partitions
in living units.Tests reported in this paper were
made on walls treated to upgrade their sound
transmission loss properties.Results indicate that
significant sound insulation can be obtained even
with relatively inexpensive procedures.
Sound transmission loss tests were made on
6 and 8 in.(152 and 203 mm)thick cast concrete
walls and on a wall constructed of nominal 8 x 8 x
16 in.(203 x 203 x 406 mm)lightweight concrete
masonry units.Sound insulation was changed by
the addition of several combinations of furring,
sound insulation blankets,and gypsum wallboard.
Tests to determine sound transmission loss were
made in accordance with ASTM E 90.Sound trans-
mission loss (STC)was determined using the pro-
cedures of ASTM E 413.
With the addition of furring,insulation,and
wallboard,STC values up to 63 were obtained on
both the 6 and 8 in.(152 and 203 mm)thick con-
crete walls.The highest value obtained on the
masonry wall was 59.However,the data indicate
that a somewhat higher STC would have been
obtained from a grouted wall with furring,insu-
lation and wallboard attached,
STC values,obtained by other investigators,for
a variety of concrete wall constructions are in-
cluded,
ACKNOWLEDGMENTS
All sound transmission tests were performed by the
Riverbank Acoustical Laboratories,Geneva,Ill.,under
contract to the Portland Cement Association.
Assistance on planning the test walls and interpreting
the test results was given by Allen H.Shiner,Acoustical
Engineer,Skokie,Ill.,and Keith Walker,U.S.Gypsum
Acoustical Laboratory,Round Lake,111,E.A.Valko,
Senior Technician,assisted in preparing the walls for
testing,W.G.Corley,Director,Engineering Develop-
ment Department,reviewed the text of this report and
suggested valuable changes,
REFERENCES
1.“Sound TransmissionControl in ResidentialBuild-
ings,”BOCA Basic Building Code,Building Officials and
Code Administrators International,Inc.,Chicago,1976
Supplement,Section 522.
2.Southern Standard Building Code,Southern Build-
ing Code Congress,Birmingham,1976,Appendix E.
3.National Building Code,American Insurance Asso-
ciation,New York,1976,Section 380.13.
6 Sound Transmission Loss Through Concrete and Concrete Masonry Walls
4,“Sound Transmission Limitations,”Minimum
Property Standards for Multifamily Housing,Depart-
ment of Housing and Urban Development,Washington,
D.C.,Apr.1977,Table 4-4.1.
5.“Standard Method for Laboratory Measurement
of Airborne-Sound Transmission Loss of Building
Partitions,”(ASTM E 90-75),1976 Annual Book of
ASTM Standards,Part 18,American Society for Testing
and Materials,Philadelphia,pp.667-679.
6.“Standard C 1ass i f i c a t i o n for Determination of
Sound Transmission Class,”(ASTM E 413-73),1976
Annual Book of ASTM Standards,Part 18,American
Society for Testing and Materials,Philadelphia,pp.
819-821.
7.“Standard Specification for Mortar for Unit Ma-
sonry,”(ASTM C 270-73),1976 Annual Book of ASTM
Stmdamts,Part 13,American Society for Testing and
Materials,Philadelphia,pp.243-247.
8.“New Data on Sound Reduction With Concrete Ma-
sonry Walls,”NCMA-TEK 69,A,National Concrete Ma-
sonry Association,McLean,Va,,1978,4 pp.
9.“A Study of Techniques to Increase the Sound In-
sulation of Building Elements,”W~le Laboratories Re-
port No.73-5,Department of Housing and Urban
Development,Washington,D.C.,June 1973,216 pp.
For certain applications,the use of sound transmission
class (STC)valuesis not sufficient.For those who require
additionaldata,sound transmissionlossvaluesversusfre-
quency were plotted.Figures for each specimen tested are
presented here.Test numbers shown correspond with test
numbers in Table 1 of the text.
70
60
~50
S-
y
40
s
G
g
~
~30
K1-
a
z
;20
10
0
FREQUENCY,HERTZ (cycLEs PER SECOND)
J 160 I 250 I 400 [630 I CO
2 5 1000
,
I
FREQUENCY,HERT2 (CYCLES
II E
rc Contour
STM E413)
E
est No.76-68
TC =59
K
Z@lm
2 5 10000
PER SECONO)
80
70
60
g 50
i
g 40
$
~
~30
a1-
a
z
;20
10
0
FREQUENCY,HERTZ (CYCLES PER SECOND)
PCA Research and Development BulIetin 7
80
70
60
g 50
10
0
FREQUENCY,HERT2 (CYCLES PER SECOND)
80
70
60
g 50
9
9
40
6
G~
~
~30
E1-
n
z
.3 20m
10
0
FREQUENCY,HERTZ (CYCLES PER SECONO)
70
60
g 50
$
9
z 40
Q
m~
~
$30
m1-
0
z
;20
10
0
FREQUENCY,HERT2 (CYCLES PER SECONO)
80
70
60
~50
g“
9
40
6
g
g
~30
ak
az
~20z
10
0
FREQUENCY,HERT2 (CYCLES PER SECOND)
*
-Sound Transmission Loss Through Concrete and Concrete Masonry Walls
80
70
60
50
40
30
20
10
0
FREQUENCY,HERTZ (CYCLES PER SECOND)
80
70
60
50
40
30
20
10
0
FREQUENCY,HERTZ (CYCLES PER SECOND )
70
60
50
40
30
20
10
0
FREouENcy.HERTZ [cYcLEs PER SECONO)
70
60
m
.50
%
9
40
5
Gg
~
z 30g
nz
;20
10
0
FREQUENCY,HERT2 (cYcLEs PER SECOND)
PCA Research and Development Bulletin 9
70
60
:50
g-
9
40
z
g
g
~30
E
0
z
;20
10
0
FREQUENCY,HERTZ (cYcLEs PER SECOND)
70
60
g 50
$-
9
g 40
$
%o
5 30a+
0
z
g 20
10
0
FREQUENCY,HERTZ (cYcLEs PER SECOND)
70
60
g 50
~
g 40
~
s(n
~30
E
n
z
;20
10
0
FREOUENCY,HERT2 (cYcLEs PER SECOND)
FREOUENCY,HERTZ (CYCLES PER SECOND)
Portland Cement
Association Member
Companies
(as of Aprtl 1980)
United States
Aetna Cement Corporation
Alamo Cement Company
Arkansas Cement Corporation
Ash Grove Cement Company
Atlantic Cement Company,Inc.
California Portland Cement Company
Capitol Aggregates,Inc.(Capitol
Cement Division)
Centex/Nevada/Texas
Citadel Cement Corporation
Coplay Cement Company
Cyprus Hawaiian Cement Corporation
Flintkote Cement Company
Florida Mining &Materials Corp.
Giant Portland &Masonry Cement
Company
Gifford-Hill Portland Cement
Company (a subsidiary of Gifford-Hill
&Company,Inc.)
Ideal Basic Industries,Cement Division
independent Cement Corporation
Kaiser Cement Corporation
Lehigh Portland Cement Company
Lone Star Industries,Inc.
Louisville Cement Company
Marquette Company
Martin Marietta Cement
The ,Monarch Cement Company
Monolith Portland Cement Company
National Gypsum Company
Northwestern States Portland
Cement Co.
OKC Corp.
Oregon Portland Cement Company
Rinker Portland Cement Corporation
Rochester Portland Cement
Corporation
Santee Portland Cement Corporation
The South Dakota Cement Plant
Southwestern Portland Cement
Company
Wyandotte Cement Incorporated
Canada
Canada Cement Lafarge Ltd.
Ciment Quebec,Inc.
Federal White Cement Ltd.
Genstar Limited
Lake Ontario Cement Limited
Miron Inc.
North Star Cement Limited
St.Lawrence Cement Co,
St.Marys Cement Limited
This publication is based on the facts,tests,and authorities stated herein.It is
intended for the use of professional personnel competent to evaluate the sig-
nificance and limitations of the reported findings and who will accept respon-
sibility for the application of the material it contains.Obviously,the Portland
Cement Association disclaims any and all responsibility forapplication of the
stated principles or for the accuracy of any of the sources other than work per-
formed or information developed by the Association.
----------------------------------------------------
I
I
I
I E2
I
I
I
I
I
I
I
I KEYWORDS:acoustic insulation,acoustic properties,building codes,concrete
I
I I
I panels,furring,masonry walls,noise reduction,residential buildings,sound trans-1
I I
I mission,wallboards,walls.II
1
I
1
I
I
I
I
I
t
I
I
I
I
1
ABSTRACT:Many building codes require minimum sound transmission 10SS II
values,expressed as sound transmission class (STC),of 45 to 50.Tests of sound I
transmission loss were made on 8-in.-thick (203-mm)concrete masonry walls and on
I
I
6-and 8-in.-thick (152-and 203-mm)cast concrete walls finished with materials in-1
I
tended to increase sound transmission loss.Using furring,acoustic insulation,and I
wallboard attachments,STC values up to 59 and 63 were obtained for the masonry
I
I
and cast concrete walls,respectively.Selected STCvalues,reported by other investi-1I
gators,for a variety of walls are included for reference.II
i
I REFERENCE:Litvin,Albert,and Belliston,Harold W.,Sound Transmission LOSS I
I
I
1 Through Concrefe and Concrete Masonry Walls (R D066.O 1M),Portland Cement I
I Association,1980.Reprinted from A Cl Journal,December 1978.I
I
I
I
I
I
I
I
I
-------------------------------------------------------------I
PORTLAND CEMENT mlII ASSOCIATION
An organization of cement manufacturers to improve and extend the uses of portland cement and concrete through scientific research,engineering ficfd work,and market development.
5420 Old Orchard Road,Skokie,Illinois 60077
Printed in U.S.A.RD066.OIM