VSV

SWrucWural Analysis of HisWorical ConsWrucWions – Jerzy Jasieńko (ed) © 2012 DPNH ProcławH PolandH ISSN 0860-2395H ISBN 978-83-7125-216-7

bFFbCTS lF iIMb MlRTAR abSIGN lN MbCeANICAi PRlPbRTIbS lF eISTlRICAi MASlNRY UNITS Bekir vilmaz mekmezciNI eakan kuri Atahan2I fşıl molat mekmezciPI brman viğit Tuncel4 ABSTRACT aramatic variatiçns çf mechanical prçperties are determined frçm çn-site experiments which are cçnducted çn existing masçnry structures. The reasçns çf the variatiçns are either durability factçrs affecting the structure çr the design and prçductiçn parameters çf the materials. fn this experimental studyI a set çf tests were cçnducted çn the reprçduced masçnry units in the labçratçry in çrder tç understand the effects çf pçzzçlan-lime mçrtar mix prçpçrtiçns çn the perfçrmance çf histçrical masçnry units. As the main results çf the experimental studyX althçugh cçmpressive strength çf mçrtars are related directly tç mçrtar mix designI the cçmpressive strength çf masçnry units are dependent tç mçrtar mix design and prçperties çf clay bricks used. clexural strength çf the mçrtars and shear strength çf masçnry units are decreasing with increase çf binder amçunt in the mixture due tç the shrinkage cracks in high dçsage mçrtars and their interface with brick. Capillary water absçrptiçn cçefficient and water absçrptiçn values alsç increases with increase çf binder in mçrtars due tç the cracks fçrmed. heywords: mozzolanI iime mortarI MasonryI phear strengthI Compressive strength N. INTRlaUCTIlN aramatic variatiçns çf mechanical prçperties are determined frçm çn-site experiments which are cçnducted çn existing masçnry structures. The reasçns çf the variatiçns are either durability factçrs affecting the structure çr the design and prçductiçn parameters çf the materials. jasçnry is a typical cçmpçsite cçnstructiçn materialI which is suitable tç carry the cçmpressive lçadsX hçwever its capacity tç carry the tensiçn and shear is relatively lçw. As a result çf nçn-hçmçgeneity and anisçtrçpy çf masçnryI the relatiçnships between the mechanical characteristics çf masçnry at shear and cçmpressiçn are significantly different than in the case çf the hçmçgeneçus and isçtrçpic materials xNz. Because çf specific characteristics çf each cçnstituent materialI it is nçt easy tç predict the mechanical prçperties çf a specific masçnry cçnstructiçn type by knçwing çnly the characteristics çf its cçnstituents xNI 2z. There are many parameters affecting the perfçrmance çf masçnry. The physical and mechanical prçperties çf substrate are an impçrtant factçr affecting the perfçrmance çf the masçnry interfaces between bricks and mçrtars xPz. These parameters affect the mechanical interlçcking between the mçrtar and substrate. The prçperties çf the binding materials is ançther impçrtant factçr affecting the shear perfçrmance çf masçnry x4I Rz. The surface cçnditiçn Esmççth çr rçughF influences the cçmpçsite behaviçr çf masçnry under cçmpressiçnI mçstly with respect tç the cçmpressive strengthI mçdulus çf elasticity and defçrmatiçn at peak stress. The material çf the bed jçints Elime mçrtar çr clay materialF influences cçnsiderably the failure mçde and the cçmpressive strength çf stçne masçnry xSz. aue tç its inhçmçgeneityI hçmçgenizatiçn mçdels are being develçped xTz

N arI fstanbul Technical rniversityI caculty çf Civil bngineeringI pekmezcibN]itu.edu.tr 2 arI fstanbul Technical rniversityI caculty çf Civil bngineeringI atahanh]itu.edu.tr P oes. Asst.I fstanbul Technical rniversityI caculty çf ArchitectureI isilp]yahçç.cçm 4 oes. Asst. fstanbul Technical rniversityI caculty çf Civil bngineeringI yigittuncel]yahçç.cçm

VTM

fn this experimental studyI a set çf tests were cçnducted çn the reprçduced masçnry units in the labçratçry in çrder tç understand the effects çf pçzzçlan-lime mçrtar mix prçpçrtiçns çn the perfçrmance çf histçrical masçnry units. O. bXPbRIMbNTAi abTAIiS Clay brick specimens used in the study were taken frçm NNM years çld masçnry structure. The lime-mçrtar mix prçpçrtiçns were designed tç be cçmpatible with histçrical mçrtars taken frçm several masçnry buildings. katural sandI pçzzçlan Egranulated pumiceFI and lime were used fçr prçductiçn çf mçrtars. The prçperties çf natural sand and pçzzçlan are given in Table NI 2 respectively. iime was kept fçr N year after hydrating prçcess. uoa pattern çf the lime is given in cigure N.

Table N mrçperties çf natural sand

pieve sizeI passing thrçugh EBF ppecific gravity EkgLmPF

Bulk density EkgLmPF

tater absçrptiçn

EBF U 4 2 N M.RM M.2R

2R2M NRNM N.NN NMM NMM VM UM SM U

Table O mrçperties çf pçzzçlan

ppecific gravity EkgLdmPF Blaine specific surface area Ecm2LgF

Tp 2R mçzzçlanic activity index EjmaF

2.RM PSMM NN.U

Fig. N uoa pattern çf lime mçzzçlan-lime mçrtars were prepared accçrding tç three different mix designs. mçzzçlanWlimeWsand ratiçs çf the mçrtars prçduced are M.RWM.RWNI M.RWM.RW2I M.RWM.RWP. The ratiçs cçrrespçnd the binder tç sand EbWsF ratiçs çf NWNI NW2 and NWP respectively. tater tç lime ratiç were adjusted accçrding tç cçnstant wçrkability. tçrkability kept cçnstant as NU cm flçw after NR drçps çn drçp table accçrding tç ApTj CN4PT-MT drçp table test. jçrtar specimens having the dimensiçns çf 4 × 4 × NS cm were prçduced fçr flexural and cçmpressive strength tests. The pieces taken frçm flexural strength tests were used fçr cçmpressive strength tests. cçr determinatiçn çf cçmpressive perfçrmance çf masçnry unitsI units having R clay brick and 4 bed jçints were used. cçr shear perfçrmance testI masçnry units having P clay brick and 2 bed jçints were prçduced. jçrtar specimens were kept in air curing during first 24 hçurs and then transferred RR°C envirçnment. The samples were kept in RR°C during N week.

VTN

Then the samples were stçred in SR ±RB relative humidity and 2M°C labçratçry during additiçnal 2U days. At the end çf curing timeI determinatiçn çf cçmpressive and flexural strength çn mçrtars specimens was carried çut. Cçmpressive strength and shear perfçrmance çf masçnry units were alsç determined. aeterminatiçn çf capillary water suctiçnI water absçrptiçn tests were applied çn mçrtar specimens at the end çf curing periçd as well. bxperimental study was cçnducted çn minimum R specimens çf each series. Cçmpressive strength tests were alsç applied çn brick specimens which were taken çut frçm NNM years çld building. The detailed drawing çf the brick specimen used in the prçductiçn is given in cigure 2.

Fig. O The brick specimen

The detailed drawing çf masçnry unit and test setup çf cçmpressive strength çf masçnry unit is given in cigure P. Clçse lççp test device was used fçr cçmpressiçn and shear tests. The test was cçntrçlled by means çf displacement during test. The displacement was kept as M.N mmLminute as cçnstant.

Fig. P Test setup and masçnry unit fçr cçmpressive strength test

The detailed drawing and picture çf masçnry unit shear test setup is given in cigure 4. Test setup is kept similar tç the system described in bk NMR2-P standard. M.2 kk çf pre cçmpressiçn stress was applied çn all the specimens.

VT2

Fig. 4 Test setup and masçnry unit fçr shear strength test

P. TbST RbSUiTS ANa aISCUSSIlN Cçmpressive strength test results çf clay bricks are given in Table P. Althçugh the brick cçurse samples were taken frçm the same buildingI very high cçmpressive strength variatiçn was determined. The maximum cçmpressive strength çf clay brick was 24.4 jma while the minimum was T.V jma. Average value was calculated NR.U jma while standard deviatiçn was S.MU jma.

Table P Cçmpressive strength test results çf bricks

Brick number

Crçssectiçnal area Emm × mmF

jaximum fçrce EkkF

Cçmpressive strength EjmaF

N 2NM × VR NSN.R U.N

2 2MR × V4 PP4.V NT.4

P 2MR × NMN 42R.U 2M.S

4 2MR × VS PVU.S 2M.P

R 2NP × NMM NSV.P T.V

S 2MS × VU 4MT.S 2M.2

T 2N2 × VT 2R4.2 N2.4

U 2NV × NMM NUV.P U.S

V 2N4 × NMP PVP.V NT.V

NM 22U × NM4 RTU.M 24.4

jechanical strength test results are shçwn in cigure R. cigure includes flexural and cçmpressive strength çf mçrtarI shear strength çf masçnry unit and cçmpressive strength çf masçnry unit. crçm cigure RI increasing binder tç sand ratiç frçm M.PP tç M.RM causes increase in cçmpressive strength values çf bçth mçrtar and masçnry units. Cçmpressive strength value çf mçrtar increased dramatically with increasing the binder tç sand ratiç frçm M.RM tç N.M. pignificant difference in cçmpressive strength çf masçnry unit was nçt determined with increasing binder tç sand ratiç frçm M.RM tç N.M. This difference between mçrtar and masçnry unit cçuld be attributed the limited strength çf clay bricks used in prçductiçn çf samples. pince the strengths çf sçme clay brick were exceeded the strength çf the system did nçt have higher values. cailed brick samples in masçnry unit were shçwn in cigure S. fn figure SI it is seen that failure was çccurred with failure çf brick in the system.

VTP

0,00

0,20

0,40

0,60

0,80

1,00

0

1

2

3

4

5

6

0,00 0,20 0,40 0,60 0,80 1,00 1,20 Flex

ural

and

she

ar s

Wren

gWh

(MPa

)

Com

pres

sive

sWr

engW

h (M

Pa)

binder Wo sand raWio

compressive str (mortar) Compressive str (masonry unit)

shear str (masnonry unit) flexural str (mortar)

Fig. R jechanical strength test results

Fig. S cailed masçnry unit in cçmpressive strength test plight decreases fçr bçth flexural and shear strength values with increasing binder tç sand ratiç were determined in cigure R. This cçnflict with cçmpressive strength values was attributed tç very high magnitude çf shrinkage values çf bed jçint mçrtars having higher binder tç sand ratiç. eigher shrinkage cçuld cause micrç cracks. pince micrç cracks have mçre impçrtant rçle in flexural and shear strengthI a slight decay was determined while cçmpressive strength gaining was çbtained with increase çf binder tç sand ratiç. The bçnding perfçrmance çf bed jçint mçrtar and brick cçuld alsç be affected by shrinkage and micrç cracks fçrmed due tç shrinkage. micture çf specimens having different binder tç sand ratiçs are given in cigure T. cigure Tb shçws the specimen with the binder tç sand ratiç çf N.M have even macrç cracks after S mçnths. kç visible cracks çn the samples with the binder tç sand ratiçs çf M.PP and M.RM seen in cigure Ta.

EaF bLs W M.PP

EbF bLs W N.MM

Fig. T sisible crack çbservatiçn çn bLsWN.MM and bLsW M.PP mçrtars

sisible marcrç cracks çn mçrtar

VT4

fn çrder tç clarify the behaviçr under shear fçrcesI shear stress-deflectiçn curves are given in cigure U. mlastic defçrmatiçn fçllçwing certain stress is determined in all three series çf the mixtures with different binder tç sand ratiçs. After the certain shear stress is reachedI cracking çccurs and the mechanical bçnding between mçrtar and brick is failed. crictiçn fçrce between mçrtar and brick becçme the efficient mechanism beyçnd this pçint.

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,00 2,00 4,00 6,00 8,00 10,00

Shea

r SWr

ess

(MPa

)

MisplacemenW (mm)

0.33

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,00 2,00 4,00 6,00 8,00 10,00

Shea

r SWr

ess (

MPa

)

MisplacemenW (mm)

0.50

EaF phear stress-displacement relatiçn çf bLsW M.PP

EbF phear stress-displacement relatiçn çf bLsW M.RM

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,00 2,00 4,00 6,00 8,00 10,00

Shea

r SWr

ess

(MPa

)

MisplacemenW (mm)

1.0

EcF phear stress-displacement relatiçn çf bLsW N.MM

Fig. U phear stress-displacement relatiçns çf masçnry units Capillary water suctiçn test results çf lime mçrtar specimens are given in cigure V. cigure V shçws thatI increasing the sand ratiç in unit vçlume çf mixturesI decrease the amçunt çf capillary water suctiçn çf mçrtar. Binder tç sand ratiç çf M.PP mixtureI having the highest amçunt çf sand in unit vçlume çf mixture has the lçwest capillary water suctiçn cçefficient. The magnitude çf the difference between bLsWM.RM and bLsWM.PP is much higher than that çf between bLsWN.MM and bLsWM.RM

0

0,0001

0,0002

0,0003

0,0004

0,0005

0,0006

0,0007

0,0008

0,0009

1 2 3

Coef

ficie

nW o

f cap

illar

iWy

Fig. 9 Capillary water suctiçn çf mçrtars tater absçrptiçn test results çf mçrtars are given in cigure NM. tater absçrptiçn test results shçw a similar trend with capillary suctiçn results.

bWs N.MM M.RM M.PP

VTR

0

5

10

15

20

25

1 2 3

PaW

er a

bsor

pWio

n by

wei

ghW(

%)

Fig. NM tater absçrptiçn çf mçrtars cigure NM shçws thatI increasing the sand ratiç in unit vçlume çf mixturesI decrease the water absçrptiçn çf mçrtar. Binder tç sand ratiç çf M.PP mçrtar have the minimum value çf water absçrptiçn while bWsWN.MM mçrtar has the maximum. The higher capillary water suctiçn and water absçrptiçn values çf the mçrtars having higher binder tç sand ratiçs cçuld alsç be attributed tç higher shrinkage cracks amçunt fçrmed in this samples. 4. ClNCiUSIlNS Based çn the results çbtained frçm experimental studiesI the fçllçwing cçnclusiçns can be drawnW Cçmpressive strength çf the masçnry unit is limited by strength values çf mçrtar and brick cçurses. Twç different cçmpçnents çf the system affect the cçmpressive strength çf masçnry unit independently. Cçmpressive strength çf the pçzzçlan lime mçrtars increase with increase çf binder. pince cçmpressive strength çf masçnry unit is limited with the strength çf either clay brick çr pçzzçlan lime mçrtarI the same trend was nçt çbtained with the mçrtars. clexural strength çf the mçrtars and shear strength çf masçnry units slightly decrease with increase çf binder tç sand ratiç. This decrease was attributed tç micrç and macrç cracks fçrmed due tç shrinkage in high binder mçrtars and interface between higher binder mçrtar and brick. Capillary water suctiçn and water immersiçn values increases with increase çf binder tç sand ratiç due tç cracks fçrmed in this types çf mçrtars. RbFbRbNCbS xNz Tçmaževic j. E2MMVF phear resistance çf masçnry walls and burçcçde SW shear versus tensile

strength çf masçnry. Materials and ptructures 42W UUV-VMT. x2z Cbk E2MMMF Methods of tests for masonry units – part N: determination of compressive strengthK

bk TT2JN:2MMM. Brussels xPz drççt C. ENVVPF bffects of water on mortarJbrick bond. ThesisI Tehnçlçgy rniversity aelft. x4z Bei dI mapayianni f.I E2MM4F bxperimental study çf shear bçnd strength çf traditiçnal masçnry. fnW

mrocK NPth fntK Brick and Block Masonry ConfI AmsterdamI NUN-NVM. xRz Chryssi-blpida A.I sintzileçu b. E2MMUF fnterventiçns tç histçric masçnries W fnvestigatiçn çf the

bçnd mechanism between stçnes çr brick sand grçuts. Materials and ptructures 4NW 2RR-2ST. xSz d. sascçncelçsI m.B. içurençç E2MMVF bxperimental characterizatiçn çf stçne masçnry in shear

and cçmpressiçn. Construction and Building Materials 2PW PPPT-PP4R. xTz wucchini A.I içurençç m.B. E2MMVF A micrç-mechanical hçmçgenizatiçn mçdel fçr masçnryW

Applicatiçn tç shear walls. fnternational gournal of polids and ptructures 4SW UTN-UUS.

bWs N.MM M.RM M.PP