The effect of brick type on the compressive strength of masonry

4.a .2
THE
EFFECT OF BRICK TYPE
ON THE COMPRESSIVE STRENGT OF MASONRY
A.
~U I ZER
M . A . \1AR D
DepaY'tment of Civil EngineeY'ing, Unive Y's ity
o f"
CalgaY'y , CalgaY'y , Cana,fa
DER EINFLUSS DER ZIEGELSORTE AUF
DIE DRUCKFESTIGKEIT VON MAUERWERK
THE EFFECT OF BRICK TYPE ON THE
COMP'?ESSIVE STRENGTH OF MASONRY
CurY'ent practice in NOY't h AmeY'i ca genera lly utili ses
In NOY'damerika ist es úolich KOntY'ollveY'suche an
mOY' taY' and masonY'Y unit tests foY' contY'ol purposes on
bestimmten MaueY'WeY'kseinheiten auf der Baustelle
site .
In this initial study of bY'i ck assemblages a
dUr'chzufúhren . In dieseY' BetY'ac htung von Ziegel-
f our high stack - bonded compression prism and a two
maueY'weY'kskoY'peY'n wurden vier - ziegelhohe VeY' -
bY'ick sheaY' pY'ism weY'e evaluated in Y'elati on to the
suchskórpeY' im SchoY'nstein- VeY'band und unteY'
cUY'Y'ent tests , OY' t hose being pY'oposed, of ASTM and
Druckbelastung sowie z wei- ziegelhohe ZiegelpY'i s-
CSA .
men unteY' SChweY'belastung unteY'sucht und die VeY'-
The data fY'om 300 compaY'ative laboY'atory tests
weY'e analy sed .
Good cOY'Y'elation was obtained between
the assemblage and the component r esults .
The most
suchseY'gebnisse aufgeweY'tet in Bezug zu den lau f enden üblichen Tests odeY' zu den von ASTM und
consistent cOY'Y'elation was obtained with the fouY'
CSA vo rgeschlagenen Methoden . Die Daten von 300
bY'ick stack- bonded compY'ession pY'ism .
veY'g le ichenden LaboY't ests wurden analysieY't . Dabei wur de eine gute UebeY'einstimmung zwischen den
UnteY'suchungen an den oben beschY'iebenen ZiegelkorpeY'n und den andeY'en zum VeY'gleic h heY'angezogenen Erg ebnissen f estgesteIIt . Die genaueste
UebeY'einstimmung wurde mit dem vieY'- ziegeIhohen
VersuchskórpeY'n im SchoY'nsteinveY'band unteY' DY'uckbeIastung f estgest eIIt .
L ' INFLUENCE DE LA SORTE DE BRIQUE SUR
LA RESISTANCE A LA COMPRESSION DE LA
DE INVLOED VAN DE BAKSTEENSOORT OP
DE DRUKVASTHEID VAN METSELFERK
MACONNERI E
In NooY'd- AmeY'ika wordt in de r egeI gebY'uik gemaakt
En AméY'ique du NOY'd on fa it en généY'al usage d ' essais
van pr oeven op mOY'tel en metseIweY'ke lementen voor
sv~
werfkontY'o Ze .
moY'tieY' et élément s de maçonneY'i e pOUY' le contY'ô le
suy' chantieY' .
I n de ze vooY'beY'eidende studie werd de veY'geIijking
Dans cette étude pY'épaY'atoir e la compaY'aison est éta-
gemaakt tussen een pY'oe f eIement ondeY' vOY'm van een
blie entY'e un élément pOUY' essai sous f orme d 'un
4 steen hoog pY'isma en de gebY'uike Iijke tests zoal s
prisme d ' une hauteuY' de 4 bY'iques et les t ests usuels
die van het ASTM of CSA.
tels que ceux du ASTM ou CSA .
De gegevens ui t 300 veY'geIijkbaY'e laboY'atoY'iumt ests
Les données de 300 tests de laboY'atoiY'es compaY'ables
ont été analysées .
Une bonne cOY'Y'élation a été ob-
wOY'den geanaIyseeY'd .
Goede kOr'Y'eIatie weY'd bekomen
tussen de Y'esuItaten op metseIweY'k en de Y'esultaten
tenue entY'e le s Y'ésu l tats sur maçonneY'ie et ceux sur
op de komponenten .
La meilleuY'e cOY'rélation a été
tY'ouvée pOUY' des essais de compY'ession suy' des pY'ismes
d 'une hauteuY' de 4 bY'iques .
den bij dY'ukpY'oeven op
les composants .
De beste kOY'Y'elatie werd gevon;1
steen hoge pY'isma ' s .
4 ..~ .
HJTf,OOUC TIDN
In [an adR I
,
the United Sta tes 2 and Australia , the com-
p r ~"'ssi\je
st r 8ílg th of b rick rT1ôson r y [ f I ) 1 5 norrnally
~,8t.at1 1.isr€c us i ng ô tab l E ciBvp- lc pe d f~'r the Structul'al
tests . See Tab l e 1. Ttle l irlsar regress ion 1ine i5
plotted for bo t n pr ism/mortar relationships a rld the
RMS 0 1'1'01' for each r e l ationship i s a ls o given . lhe
RMS er ror for the wi r e c ut brick p rism is un f ortunateIV ~uite high but th e regr essiun lin o does confor~ to
the expected tr e nd .
Cla:,' F'f'ClDUr::ts Institute (SCPI) some 40 y eil r s a[: o . Th"
df3si.;,r'c, r -J,I8 r S U",8 tuole ',vi th tllS martar type and th e
sln~~lG b ~ ick ~o~p ~ cs5ive st rengt h a nd l edves with an
usLl'1a;:8 .Jf f ', The table dCl2s nnt cJiff e r e nt.i.at e 11et'Jean ~l'ic~ t~pes .
In this pape l' the use Df this s tandard Lable i5 r e 8xilmined us~ng the t wo most typicôl bu t different
::: !'isk 1"yps= Lsed j n r~o rt h Arle ricu dn cJ e l sel/f llere . the
st~nd;'J'~(1 ::r:Jsserj r3nd standa rd wi r e cut Ln' j CK .
lhe
i 0stlfjcalion F~r res o rting to prism testing , even for
1030 bearing j obs , i s evaluated .
sn~ll
TEST PROGRAM DETAILS
The
prisn used i n this study was a four high
unit , Its method Df ma nu fac t ure and
t85t 1s desc ri bed in ~ustralian Standa rd AS CA47 and
A~8rjcan Soc i ety ~o r Tpsting M3 terials Standard E- 447 1874 ~ith ths s xc8~ti on tilat a stea l jig was used to
COf' ~,lt rucc the p ;- ism .
The rrethod of casting v,ias desc rl jsj in 3n earlie r' oape r 4 •
br ~ ck
stac~
~and dd
The t~o bricks c hosen were both msn ufac tured by IXL
I r,oustriss ir ':eo::iclne Hut , Albe rta . Enough cal lets
wer e 5u~~lied at Lhe D8g inning of t fle orogram to comolsce thu study . T'1e b rid, s typica llV r epresent the
tw a lal'ze clas3es of b ri ck manlJfacturB~ on the North
,\m.;ri CCJ" :-;on L i ner.t . p, descript.ion uncl the nro;Jerties
cf thc! b l 'j.cf~ 3S dete rmtnad ôcco rd:Ln8 to ~STM C67 are
giv8íl in TGble 1 .
rhe t8ns ile st l' s rlc t h \tJa s obtained
fr om a non-standa r ct tansils sp litt i rl g tS3t devised by
the ss~io~ a~t ho r5 bi)S~d on t~e now fami l iar cylinder
splittirlg tBSt for cnrlcrete .
P rior to lay j ng t he b ric ks used were br o ught to an
initi~1 rate ni absorption of appro ximate l y 20-25 gm/
se . i
~l • / r~i '1 •
mortal' u3ed was nOl'1in ally an ASTM Tyo e OS " mortar ,
~u2c ifi c mix (jesign used had the same mix propurticn3 and \vor.~al)il itv ar,d had a sim i lar air c on "
terlt t'l t!'--i'3nty - fou r candomly sa mp l ed s:i t e mixp. s dp.sc r'ijed in an sG rli or study 6 . That is , th e test nixes
conta~ncd the same mix oroportions as dete rm irled i n
the site wet - s iave analysis and t he s ama s ita measured
'.'IorkFl~,ility (flmlj .
The air content was als o similar
sirlce t~e mix i llg r edients , Mixer d nd mj.x i ng time were
similar to tnos3 used on sits . The p r opsrties of the
~ortar used were aS35ssed eQch time prisms were lay ad
cc cc r d i ng to botn ~SrM [780 and CS A 179 and are given
in T~ble 2 . ~ sieve analys is and b ulking test of the
morta~ sand was also ccnduc ted .
T~ o
T~ e
DIS CUSSIO~!
I n t~e 1975 version of th e NBC af Canadu , as in many
Df the othe r major' masonry cedes , f ' for b ric ~ masonry
constructio n ca n be estab li shed usi~g ei t he r (1) a
table wh i c h uses the mortar typ e and br ic~ st r ength as
the independen l variablR s 01' [2 1 p ri sm tests involving
the job materiaIs . The t ab l es used in the f o rmeI' are
pres ented graphically in Fi g , 2 .
Ente ring Fig . 2 wi th th e mortal' type used in this pr o gram , type S , ôll d tl18 b ri cl, s:re nEths 4700 ps i [32 . 4 ~.J/
mrn 2 ) e;nd 11 , 75 0 psi ( -51 , O \J/mm 2 ) , for the presseci and
wire cut bricks r espectiv8ly , the indicated f ' value s
given in Tab l e 2 a r e obta i ned . It should be ~ot8d
that t Me c o rr8sDonrlin~ f ' fo r the two series fro m the
pI~ ism tests ere reve r ;edmin order .
AS5uming tha~ the true value for f ' is estab l isl,ed by
lhe prism teses us in g th e job mate~ials it is int e restir:g to not8 that vii til the tdbular methud f ' \"as
on ly 4 4 ~ of ac tual ."Iit.h tll8 pressed b ricf', butm',vas 10%
high '.'li tI-, t Cie vii re cut bri ck .
Since p laten re st rai nt has been s~own 7 to be Df considerable imQo rti1nce in determini n~ the node of
failure Df concrete cu bes . a pil o t p r ogram was undertak e n t o meas ur e the lo n ~jt ud 1nal and lat8ral strain
on Ihe tvlO brick t.yp8S i n tlo t h tne single b rick and
prism tests . Al thoug h the r esults h:ere rlot conclusiv8
it was apoarent tha t in tCis single brick test the
l on gitudinal and la t e r a l stiffnS35 :lf the wir'e cut
b rick W0 5 con siderably greater t!lan the p r'a3sed b r ick .
It is thers 'f o ra clea r that the effec~ o f tne rnortar
int e r laye r in G or i sm ",\1 i 11 hé3ve a 'Tio r e serious effect
on th s "sti f fer " (w i re c u tJ b r ick th.:~n Oll the "soft2r "
(pressed) brick . In the l at te r caee thp lateral
st rain Df the mortar under 10:::d i3 m~rs cornptl"::iLJle
~"fi t h the Poi sso n ' 5 5 trai n uf the b ric i<-. redlJc:l~g the
tensile sp1i ttin g effBct Df the mo rt a r . fhis qualitative 2r ~\Jment does e xplain tlle test r esu lts obt ained ,
tt1at .is , thB signi'f-"icêlntly hit;hec ;.;r:sll st r er.g t'l
obta i ned with th e softer pr essed brick ,
CONC LUSIONS
1.
In alI but the's mal lest engineered load besring
mas o nry b rick structures , f ' 3hould be d8termined
from prism tests lIsing job f}bterials.
Fai1u re to
follow this recommendBti o n can result on the one
hand in a ve ry uneconomical struct l! re and conversely to a st ruc tu r e whers tllo Dverall safety
facto r i 5 comp r om ise d , u rlwittingl y .
2.
c onclu si on o~ e , a n exhaust i ve pr o gram of component mOI'tar tests are re qu ired ~o
establish more accur a t ely t ne relati on s hip between
componen ts strengths ano p r ism st r engths for
specific bricK types . Tables of t hese results
might then be a more meaningful substituta for the
above recomme ndat ion .
test program ccrlsistad of a se r ias Df ~ortar and
oris n tests usirlg the job sita mnr tar mix des i gns
'fhe
esta jlishsd in t he concurr8n t f i e l d testing programo
On each t9 St dai . the mortar wa s tested ôn d o ne set
of ;:;risnó [3 speci rnensJ \:J Bre layed . On some occasians
one set o f prisns were manufactured fo r 8BCh Df ths
two b rick types . In alI , 36 se ts of 3 specimens we re
manufactured and tested ; 12 p r esse d bricK pr isma and
24 1.'1 i I'8 cut ;) rick :I risrns .
2-1
N ot ~~ it hst anding
RESU I_ TS
ACKNOWLEDGEME NTS
The 28 - day prism and corresponding mortar test re sul t s
élre given in Fig . 1 . The scstter '.'I:l th the pr essed
brick p rt sms is s ubs tantially 1055 th an with th e wi re
cut bric~ out this is to be expect ed since a simila r
rsl~ti v8 va riao ility waS observe d in the
single unit
The authors wis h to thank the National Research Counc il
of Canada and the Alberta Masonry I nstitute f o r their
financiaI s upport . Messrs . C. Klaver and M. Smith
carried out the tests discussed in the caper .
4. a . 2 -2
I~E FERENCES
1.
NJti ona l Bu il di ng Cod e of Cane do 1975 . Se c t ion
4 . 4 . Pla in Re in f orced Ma so nry . pp . 41 .
2.
Recommen ded Practice for Ensi ns sred Bric k
Mos onry , St ructu r al Clay Products I nsti t ute , 1969 ,
pp . 338 .
4000
y = 040x + 2 70 0 psi
3.
RMS
St andard s ~sso c ia t i on Df Aus t ralia , Br irkwo rk
Co de [metric) iIS -164o - 1974 , pp . 126 .
~
o-
4.
Huizer , (' . , "Eff ec t of Mo c t a r PnJperties on Co mpressio n Pcis m - , Shea r Bon d - an o Be nding Bond
Contro l Tests f or Clay Brick Ma sonr y ", oa oe r submi tted for plJb l ic at ion , Cana di s n Society for Ci vi l
Erlgineering , pp . ~1 .
Bri c k oe velopme nt Reseacc h Inst itute Newsl e tt e r ,
I, umber 3D , Un:iv e r sity Df 118 1bo urn 8 , lJicto t'i a ,
Aus t r a l ia , March 1966 .
6.
Hui78r , A. , l,J anJ, M. A. , Mo r s tead , H.; " ,~ F iel d
a nd Lab o ra t o ry Study Usi ng Cur r en t Qnd P ropo se d
Proccd ur 8s f or TBsting Maso nry Mor'tars " , Ame ric an
3000
::!'
lO
o::
"-
y:;: 035 x t 2300 psi
RMS
2500
OL
U
Error = 470psI
Ci'
tIl
2000
•
Pres sed
3 rlck
•
E xlruded
Bnck
1500
~~
"f\lasD n ry : Past a nd
O
Prese nt" , A.5Tfl STP 5[J9 , 197 5 , po . 107-121 .
7.
= 145psi
<t
5.
Soc j. e t y for Test i ng r'1 ater ia l s ,
Error
3500
500
I
iOOO
I
I
I
1500
2000
2500
28 DAY CUS E STRE NGTH
K. , Lélc !l ,l nc8 , L. , "lh e rust i ng o f Britt l e
uml e r Urli.f o rm Ulliaxia l Comprcs s ive
Str8sS " , P roc . ,' .sTM, \fo l. 64 , 00 . 10 ,~ 4 - 6 7 , 1964 .
(pSI
i
~J5 ','lm a ll,
~l a te ria ls
TAB LE 1
F ,gure
B~ I C K
PROP ERTIE S
Se r :i es 2
Ser i es
4 " mod u la r standard - PR ESSED
comp re~sive
2
( r'J / mm )
tensil e st r en gth ,
rn8 éJ n , x
coef f . of var l at io n l %)
4 , /00
3. 6
11 ,700
9.0
450
16 . 0
60 0
24 . 2
22 0
9.3
170
21.1
mEa rl,
x
coe ff . of vacia tion [% )
~si
([~ / mm2 )
absorp tio n , %
6.5
5 hr", boil i ng t es t
a bsorpt io n , %
10 . 7
init i al ra te (] f
abS Drpt i on [ as d eli ve r s d)
gm . Isq . in . Imin .
63 . 3
rJi mensio n s , .Ln s .
2
4 " modulQr standard - EXTRUOED
stren Bth , psi
mod ul us Df r uotu r a ,
ps i [ \ l/m m2 )
[M )
1
r'J ET
GROSS
22
24 . 9 ( 0 . 161 )
27 . 6 [0 . 176)
I
3000
4 . a . 2-3
Tf'.mE 2
C10RT AR PROPERTIES
mean , x
cumpr8ssive strangttl , osi
(iJ/mm 2 j
coeff . o f va riati on
(9 . O)
1310
1710 ( 11 . ô)
19 . 4
18 . 9
eem8ntEious materialls,JocI ratio
2.9
6 .9
flow , %
140
11 . 1
63
4.1
HJ. 9
24 . 8
78
3.7
íC
3.1
cone os elratjon . mm
wdte~
re~gnt ~ vi t y .
~~ater
cont~n t J
%
% by wt .
I
fi\3Lc 3
CO~l~~risJn
l
crIek TYLJ'
' Iomi nal
Mo rta!'
~)
S
Sta~dard
5
'.-Jire cut
usin~
COnlDoncnt :a:llL
cri.ek Strenrth ,
lS~
(' !/rorr: 2 )
TI'='S
StaTlcard :J r essed
f~ O~ ain~d
lJf
Estimated f ', psi
(I'J /mm 2 ) , fr om
t-i~ .
2
P ['i.sm test o
f ' , psi
(\!:r'mm 2 )
(32 . 1))
1 , 600 (11 . 0 )
3 , 455 (23 . 7J
11 , 750 (B 1 . O;
3 , 300 (22 . 5)
2 , 900 (20 . 0 )
~ , 700
Mortar Type
15000
s
N
M
12 000
Extrud ed
10000
7500
5000
2500
o
3000
t'm
Figure
2
3500
4 000
45 00
5000