CCAA Salinity T56
Transcript of CCAA Salinity T56
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Guide to Residential Slabs andFootings in Saline Environments
CCAA T56
G
uide
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G
uide
Frt pbhed Ma 2005
CCAA T56
Cement Cncrete & Areate Atraa 2005
Except where the Cprht Act aw therwe, n
part th pbcatn ma be reprdced, tred n
a retreva tem n an rm r tranmtted b an
mean wtht prr permn n wrtn rm
Cement Cncrete & Areate Atraa.
The nrmatn prvded n th pbcatn ntended
r enera dance n and n n wa repace the
ervce prena cntant n partcar prject.
N abt can therere be accepted b Cement
Cncrete & Areate Atraa r t e.
DEsigN AND lAyouT Heen Rx Den
illusTRATioN TechMeda Pbhn Pt ltd
isBN 1-877023-15-9
Guide to Residential Slabs andFootings in Saline Environments
Cement Concrete & Aggregates Australia
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Cement Cncrete & Areate Atraa a nt-r-
prt ranatn etabhed n 1928 and cmmtted
t ervn the Atraan cntrctn cmmnt.
CCAA acknweded natna and nternatna
a Atraa' remt cement and cncrete
nrmatn bd takn a eadn re n edcatn
and trann, reearch and devepment, technca
nrmatn and advr ervce, and ben a
ncant cntrbtr t the preparatn Cde andstandard aectn bdn and bdn matera.
CCAA' prncpa am are t prtect and extend
the e cement, cncrete and cement-baed
prdct b advancn knwede, k and
prenam n Atraan cncrete cntrctn
and b prmtn cntna awarene prdct,
ther ener-ecent prperte and ther e, and
the cntrbtn the ndtr make tward a
better envrnment.
Cement Cncrete & Areate Atraa
ABN 34 000 020 486
SYDNEYOFFICE:
Level 6, 504 Pacific Highway
St Leonards NSW Australia 2065
POSTAL ADDRESS:
Locked Bag 2010
St Leonards NSW 1590
TELEPHONE: (61 2) 9437 9711
FACSIMILE: (61 2) 9437 9470
BRISBANEOFFICE:
Level 14, IBM Building
348 Edward Street
Brisbane QLD 4000
TELEPHONE: (61 7) 3831 3288
FACSIMILE: (61 7) 3839 6005
MELBOURNEOFFICE:
2nd Floor, 1 Hobson Street
South Yarra VIC 3141
TELEPHONE: (61 3) 9825 0200
FACSIMILE: (61 3) 9825 0222
PERTHOFFICE:
45 Ventnor AvenueWest Perth WA 6005
TELEPHONE: (61 8) 9389 4452
FACSIMILE: (61 8) 9389 4451
ADELAIDEOFFICE:
Greenhill Executive Suites
213 Greenhill Road
Eastwood SA 5063
POSTAL ADDRESS:
PO Box 229
Fullarton SA 5063
TELEPHONE: (61 8) 8274 3758
FACSIMILE: (61 8) 8373 7210
EXTRACTIVE INDUSTRIES OFFICE
PO Box 243
Henley Beach SA 5022
TELEPHONE: (61 8) 8353 8151
FACSIMILE: (61 8) 8353 8151
TASMANIANOFFICE:
EXTRACTIVE INDUSTRIES OFFICE
PO Box 246
Sheffield TAS 7306
TELEPHONE: (61 3) 6330 2476
FACSIMILE: (61 3) 6330 2179
WEBSITE:www.concrete.net.au
EMAIL:[email protected]
Guide to Residential Slabs and Footings in Saline Environments
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O1 Introduction 4
O2 SourcesoSalinity
2.1 genera 5
2.2 urban sant 5
2.3 Ptenta r urban sant 6
O3 SalinityAssessmentandClassifcation
3.1 genera 7
3.2 Brad-cae Rerce 7
3.3 inrmatn r New sne lt 7
3.4 inrmatn r Extn Prperte 73.5 Mearement 7
3.6 Cacatn sane s 8
O4 EectsonConcrete
4.1 genera 9
4.2 Phca Attack 10
4.3 Chemca Attack 10
4.4 Crrn Renrcement 104.4.1 genera
4.4.2 Redctn n the akant
cncrete
4.4.3 inre at
4.4.4 Crackn
O5 SiteManagement
5.1 genera 12
5.2 sbdvn 12
5.3 sne-t Devepment 13
O6 ConcreteSlabsandFootings
6.1 genera 15
6.2 Cncrete 15
6.2.1 Qat
6.2.2 strenth
6.2.3 Cver t renrcement
6.2.4 Matera
6.2.5 uncntred water addtn
6.3 Renrcement 17
6.3.1 Fxn renrcement
6.3.2 Aternatve matera
6.4 Cncretn 17
6.4.1 genera
6.4.2 Pacn and cmpactn
6.4.3 Crn
6.5 Cntr Crackn 19
6.6 Damp-Prn Membrane 20
O7 Reerences 21
Contents
Guide to Residential Slabs and Footings in Saline Environments
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Guide to Residential Slabs and Footings in Saline Environments
sat ext nt n n cata ren, bt are preent
thrht the andcape, ncdn the drer nand
area Atraa. Thee at have the ptenta t
nt n aect the andcape and arctre, bt a
the bt envrnment. increan, extn twnhp
(bdn and nratrctre) have t dea wth the
prbem caed b ant, whe nvetatn
r new devepment are metme reqred t
evaate bth the crrent tatn and the ptenta
r tre ant hazard.
Where ane cndtn ext, r are ke t devep
ver tme, the reqrement r cncrete n cntact
wth the rnd need t be aeed t enre t
drabt and atactr perrmance ver the
den e the trctre.
in term cncrete a a bdn matera, the
knwede ha r me tme been avaabe t
den and bd cncrete trctre n evere marne
expre cndtn. The ame prncpe can be
ed t enre that the cncrete ed r redenta
tn w prvde the reqred perrmance when
bjected t ane /rndwater.
Th de cnder rban ant, t mearement
and cacatn, and cver the eect ane
cndtn wthn the /rndwater n cncrete
eement. it cver e reatn t the den,
detan and cntrctn cncrete, and prvde
dance n the qat e that need t be
addreed when pacn cncrete t enre t n-
term perrmance n ane envrnment. stratee
t mnmze the eect ant are a ven. Whe
the nrmatn ma app t a cncrete member,
th dcment ce n redenta ab and
tn, a tte dance n th area crrent ext.
O1
Introduction
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Guide to Residential Slabs and Footings in Saline Environments
2.1 General
srce ant wthn the envrnment ncde:
natra ccrrn at rm marne edment, at
reeaed rm the prce /rck weathern,
at tranprted rm the cean and depted brana, r e recced 're' water cntann
at.
The tpe ant a dened b the area
n whch t ccr. Fr exampe; drand ant n
rra area, 'rratn ant' n rrated armn
and and 'rban ant' n bt-p area. Th
de dea n wth rban ant. le cmmn,
ant reerred t a ether prmar, where t
ccr natra wthn the andcape, r ecndar,
where hman nterventn ha drect cntrbted
t the devepment r expann ant (e pr
dranae and rn water tabe brnn at t the
race).
Prbem wth ant are enera nked t the
rndwater tem, a water tranprt the at
thrh the . Water mve thrh the rnd n
a andcape, enera rm hher t wer area.
The part the andcape where the majrt water
enter the water tabe are knwn a the rechare
area. A the water fw thrh the , at w
be dved and tranprted, and an ran the
water eve w th a brn an dved at
cer t the race. smetme, the rndwater
eve w reach the race, and water (carrn at)
w emere and eave at dept n the race a
the water evaprate. Area where the rndwater
and at are abe t reach the race are knwn a
dchare area.
2.2 UrbanSalinity
ste can be pt nt three catere n repect
rban ant:
n
ste wth w ant hazard. Tpca are thewhere there are w eve at, d dranae
(eachn at) r the wth tabe, deep water
tabe.
n ste that have extn ant hazard. sat-reated
prbem n rban envrnment ncde tann
race (whte dept), rettn brckwrk, dn
veetatn, bare ca 'caded' race and rapd
crrn metac tem. Fr new devepment,
nvetatn can read dent whether
there a prbem wth ant.
n ste that have the ptenta t devep a anthazard. sat are preent, bt are we bew the
race. Becae ant a dnamc tem
nvvn man varabe, ver tme, chane n
cmate, and e and and cver (rbanatn)
ma ret n rn water tabe; a, at ma be
mprted t the area.
Whe me actn can be taken t redce the rk
a ant hazard devepn, predctn hw a
dnamc tem dependent n man varabe
w perrm ver the tpca 50-ear den e a
bdn dct.
Fr te caed a havn the ptenta t
devep a ant hazard, the bet apprach
therere t accept that at me pnt n the tre
the hazard w ext and t enre that bdn
matera are capabe prvdn the reqred
perrmance n ch an envrnment.
A and becmn a carce rerce, t mprtant
that the tratee adpted t dea wth ant aw
the devepment ptenta a area t be reaed
at an ardabe ct t the cnmer. stratee
need t be thht thrh care, that mne nveted n actn that dever the mt ct-eectve
tn. Fr exampe, addn t the ct the and
b 'etate' n ver ane area ma nt be an
eectve n-term tn there t the ptenta
r capar actn t draw at t the race. it
cd be mre ecnmca t keep the and prce
dwn, and t pt mre rerce nt the bdn
den, matera and cntrctn t enre that the
are apprprate r the cndtn that ext n the te.
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2.3 PotentialorUrbanSalinity
Whe the water tabe (and dved at)
nrma at me depth wthn the pre,
raed cent the at that are brht tward
the race can aect veetatn, bdn eement
(tn and wa), ervce wthn the rnd and
nratrctre bt n the rnd (e rad). The
dct ben abe t determne the mpact a
devepment n the natra tem, and t predct
what chane w ccr t the water tabe ver the
den e trctre ch a he, and whether
thee w have the ptenta t create a ant hazard.
The dct tem rm the natra ccrrn
varabe wthn the that aect the ptn the
water tabe, e:
n The depth an mpermeabe aer ch a rck.
n The tpe and eae wth whch water can
ntrate thrh t.
n The preence deep-rted tree/veetatn that
have the abt t nt n ntercept water bere
t reache and add t the water tabe, bt a t
draw water rm cnderabe depth, ten rm
the water tabe te.
n The amnt and varabt rana.
n The rate evapratn mtre rm the .
n The capar ctn the (n ca, th ma
rae water b p t 2 m).
n The nrmt the (, a, an mpermeabe
aer wthn the pre re cer t the race
at me pnt, t ma ret n a cntrctn t the
fw rndwater, can t t re cer t the
race, and pb emere/dchare).
n The dtance between rechare and dchare
area. Fr are redenta devepment, r even
twnhp, the cmatve amnt recharn
an a pe cd exceed the capact the t dran the rndwater, eectve ran
rndwater t the race.
n The preence perched water tabe. Th
where the area ha mpermeabe matera
nderneath the race, preventn water rm
drann; thee area are cmmn bject t
watern.
Addn t the varabe preent n the natra
tem, are the varabe ntrdced thrh hman
nterventn. Thee ncde:
n Etate devepment ncdn cearn
veetatn, the cntrctn artca water
eatre, detentn ban, and etate ct and
ver are area.
n sne-t devepment and mnma cntr
ver the water ae n the te. increaed water
addtn thrh exceve watern awn and
arden ten ccr.
n Redcn natra evapratn and natra rechare
b cvern the race wth mpermeabe
pavement and trctre.
n ue water whch ma cntan dved at,e 're' water retcatn tem, bre water, etc.
n The e rbbe pt r ae pt, rechare t
the water tabe.
n leakn ervce ppe ch a water and
trmwater.
Frm the abve, t can be een that man varabe
nfence the ptn the water tabe and th
create a ptenta ant hazard. it a mprtant
t reae that the rndwater tem wthn a
devepment ma be aected nt n b chane
and actvte wthn the devepment, bt a rm
chane that ccr n the rrndn and, pb
man kmeter awa.
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3.1 General
N ne rerce r precrptve t tet can
prvde a the nrmatn reqred t determne
the ptenta r ant at a partcar catn.
The prcee b whch at mve thrh theandcape are cmpex, makn t dct t
determne the ant hazard at a pecc catn.
inrmatn n me e rerce r bennn a
ant hazard nvetatn tned eewhere1.
The rerce avaabe at preent t ae the
ptenta ant a te are decrbed bew.
3.2 Broad-scaleResources
Brad-cae rerce ch a ant-hazard map
are enera pannn t, whch dent area
knwn ant, and ma rank the ptenta ant rka hh, mderate r w.
in rban area, prece dentcatn ndvda
he t n brad-cae map ver dct, a
mch the extn nrmatn avaabe at cae
t ma r e n rban area. Hwever, nrmatn
rm brad-cae rerce can be ed t dent
the need r rther nvetatn the he t n
an area caed a at aected r ptenta at rk
rm ane cndtn.
3.3 InormationorNewSingleLotsFr ne t, nrmatn avaabe rm the
deveper, lca Cnc and reevant state
gvernment Department hd be checked, a
hd an lca Cnc reqrement r tetn t
dent the ant rk. i t dented that the t
wthn an area that ether ha an extn prbem, r
the ptenta t devep a ant hazard, actn that
need t be taken ncde determnn the extent and
eve the ant hazard r rk b ampn and
tetn. A tpca bac nvetatn wd be the
excavatn a ne randm-cated pt, wth the
ant the teted at 500-mm nterva dwn t
a depth , a, 2.5 t 3.0 m. Th w etabh the
apprxmate depth at whch ane cndtn ccr,
the eve ant and pb the ptn the
water tabe. The ct ch a bac nvetatn w
be qte mdet. Hwever, t determne the tpe
at preent, rther mre-expenve tetn wdbe reqred.
Fr ma trctre ch a a wrkhp/hed fr,
the ct ampn and tetn ma be a mch
a the ct the fr te (ncdn meare t
addre the ane envrnment), and therere nt
warranted. Even r he tn, the ct the
tetn ha t be wehed aant the addtna ct
mpementn meare t dea wth the pbe
ane cndtn, e ncrean the cncrete trenth
and, n me area, pradn the vapr barrer
beneath the ab t a damp-prn membrane(ee sectn 6.6). Damp-prn membrane have
hher mpact retance than vapr barrer and
hence reater retance t pnctrn and mtre
penetratn.
3.4 InormationorExistingProperties
on extn prperte, t nke that nrmatn
w be avaabe n the ptenta r a ant hazard.
state gvernment Department ma have brad-
cae map the area, r lca Cnc ma be
aware area at rk rm ant. Nte that de t
the varabt rnd cndtn, even n area nt
knwn r ant, the ccana he ma er
damae de t at attack.
An npectn extn der bdn n r
adjacent t the te ma revea whether r nt ane
cndtn ext n the area. Evdence ncde whte
tann/crtn n the wa and rettn r erded
brck (a near the rnd), bare patche awn
(pb wth whte appearance rm dred at),
and dn veetatn.
i there evdence at then precatn need t betaken. The can be teted t determne the eve
ant, r aternatve a cnervatve apprach can
be taken where me bac tem ch a the cncrete
trenth and/r patc membrane are attended t n
the cntrctn t prvde the reqred drabt.
3.5 Measurement
The crrent accepted wa determnn the
ant eve at a te b mearn the eectrca
cndctvt (EC) the n decsemen per
metre (ds/m). Nte that a ant eve 1 ds/m
apprxmate eqvaent t a tta be at eve
640 ppm r 640 m/l.
O
Salinity Assessment
and Classifcation
Guide to Residential Slabs and Footings in Saline Environments
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Guide to Residential Slabs and Footings in Saline Environments
The prcedre meare the crrent between tw
eectrde; cent water t dve the at and
prvde a crct between the eectrde therere
reqred. Tw methd are avaabe2:
n satrated extract eectrca cndctvt, ECe. The
atrated wth water and the eectrca
cndctvt (ECe) meared. Th prcedre take
nt accnt the textre a the ampe nt
brken dwn b mxn wth water. s textre
an mprtant actr a the at attack n cncrete
depend n the rate water mvement (and
therere the at) thrh the and hw rapd
at can be pped/repenhed at the ace
the cncrete. Th dced n mre deta ater.
n Extract eectrca cndctvt, EC (1:5). The
mxed wth water n the rat 1 part t 5 part
water and the eectrca cndctvt meared.
A the textre aect the cndctvt,
cnvern actr (Table1) are ed t etmate
the atrated extract eectrca cndctvt (ECe)
the acta , rather than the /water mxtre.
The extract eectrca cndctvt tet a mper and
ater tet methd, vn ret (even ater appn
the cnvern actr) whch are accrate enh r
determnn the reqrement r the cncrete. Wth
the atrated extract eectrca cndctvt tet, t
ma take a cnderabe tme t reach the atratn
pnt wth ch a heav ca.
3.6 ClassifcationoSalineSoils
Table2ve a brad dentn ant cae
and ther eect n veetatn. The dvn between
a nn-ane and ane enera rearded a
an ECe
vae 4 ds/m. T ve me perpectve
t the vae, the maxmm mt r hman drnkn
water an EC vae 2.5 ds/m, ane water wd
be rearded a 6 ds/m, whe the Pacc ocean ha
an EC vae abt 59 ds/m.
it hd be nted that the cacatn n Table2
wa deveped t ae the ke mpact
ant n arctra crp. it a cndered a
reanabe cacatn r ant n rban area1.
TABLE1Factr r cnvertn EC (1:5) t ECe
(baed
n Abbtt3 and shaw4)
Soiltexturegroup* Multiplicationactors
sand 17
sand am 14
lam 10
Ca am 9
lht ca 8.5
lht medm ca 8
Medm ca 7
Heav ca 6
* grp are caed r textre n the deree t
whch can be red t n the pam the hand,ee Site Investigation or Urban Salinity5 r deta.
TABLE2ECe
vae ant cae (ater
Rchard6)
ECe
Class (ds/m) Comments
Nn-ane 16 on a ew ver
terant crp ed
atactr
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Guide to Residential Slabs and Footings in Saline Environments
4.1 General
sat attack ccr rm the actn be at.
Whe the prbem acated wth ant are ten
reerred t mp a 'at damp', t mprtant t
reae that there are man derent at that can
be preent, each havn a derent deterratn
mechanm n term cncrete.
The rat the ndvda at preent expreed
a an n cncentratn. Table3 cmpare the
n cncentratn r tpca eawater wth the
nd n rndwater tet carred t n the Waa
Waa7 (NsW) area and n the at secnd Pnd
Creek8 (a majr redenta devepment) n sdne.
Cmmn at are chrde (C) and ate (s)
manem (M), cacm (Ca), dm (Na) r
ptam (K).
Meared b the cncentratn chrde n, the
rndwater n the wrt catn at Waa Waa
abt ne thrd a ane a eawater, whe at the
wrt te at secnd Pnd Creek (where at are
emern rm the creek bank) the chrde eve are
apprxmate n 20% that eawater. Hence t
mprtant t reae that rban ant enera nt
the ame a the perceptn a at water envrnment,and that at the eve preent, denn and
cntrctn cncrete redenta ab and tn
r drabt can be a trahtrward prce.
Nte that the a tet r ant, the eectrca
cndctvt tet (ee sectn 3.5), meare n the
tta be at, t de nt ve an ndcatn a t
whch tpe are preent. B knwn the cmptn
at preent, a mre accrate aement the
at attack mechanm and drabt reqrement
cncrete eement can be made, and mre-eectve
ant manaement tratee mpemented.
The three man mechanm b whch at n the
rndwater can attack renrced cncrete are:
n Phca attack
n Chemca attack
n Crrn renrcement.
Cmmn t each the reqrement r water t
dve and tranprt the at t the cncrete
race. A hh ane can be n cntact wth the
cncrete and et have n eect the dr.
Nte that a the at ma dve nt tn w,
me cde practce terate cncentratn n the
evera tme reater than n the rndwater9.
O
Eects on Concrete
TABLE3Majr n (m/) n water/
Groundwaterat SoilatSecondPondsCreek,Sydney8
WaggaWagga,NSW7
Wrt te Averae 3 te** Averae 3 te**
Averae (Creek Bank) (awa rm Creek) (awa rm Creek)
Ion Seawater Wrt te 9 wrt te 1:5 extract* 1:5 extract atratn extract
C 19500 6160 2788 4050 1253 2140
Na 11000 2900 1512 546 201 1425
s 2700 1720 761 24.6 20.1 109
M 1400 648 307 13.4 3.0 82
Ca 410 496 244 2.0 0.2 6.2
K 390 5.7 8.3 1.5 1.7 11.1
Nte: *Maxmm vae meared at the te
**The averae ncde the maxmm vae at each catn
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10 Guide to Residential Slabs and Footings in Saline Environments
4.2 PhysicalAttack
Mtre rm the can enter the cncrete
and ead t rn damp and crtaatn
at (bth chrde and ate) a the water
evaprate. Dependn n the prere exerted b
the crtaatn prce and n the trenth
the cncrete, me drptn the cncrete at the
race can ccr. Eventa the race aer the
cncrete ma be 'tened' and pb ret awa,
expn a reh race.
Wth bred cncrete eement, reh race d nt
enera becme exped t rther attack, whe
the tened aer w tpca w dwn the rate at
whch rther cncrete w be attacked.
4.3 ChemicalAttack
in ane rndwater envrnment, nt n are
chrde n preent, bt natra-ccrrn ate
dm, ptam, cacm r manem can
metme be nd n the r dved n the
rndwater. At certan cncentratn, thee ate
can chemca attack the cncrete. The evert
the attack w depend n the tpe ate preent,
ther cncentratn, mvement rndwater,
prere, temperatre and the preence ther n.
Ptenta rce ncde:
n grndwater cntann dved ate
n Dved ate rmed rm xdatn de
mnera n the rnd
n sate rm back ca ah r ca waher
reject.
sate attack tpca nvve a reactn between
the ate and cnttent the cncrete t rm
prdct whch ccp a arer vme than the
rna cmpnd. The retn wen wthn the
cncrete ead t crackn, whch n trn aw eaer
acce r rther penetratn areve eement,
th eadn t rther deterratn.
Attack rm cacm, dm and ptam ate
caed a 'mderate', whe manem and
ammnm ate are ptenta mre evere n ther
actn. Th becae the attack a reater nmber
the cncrete cnttent.
Nte that the rndwater tet ret r Waa
Waa (ee Table3) ndcate that the ptam
eve were amt nn-extent, cacm cntent
averaed ha that eawater r the wrt nnebre he, and dm cntent wa n abt 12%
that eawater. Th the ate attack wd be
btanta e areve than rm eawater. At
secnd Pnd Creek the vae were cnderab
e aan.
Where dene, d-qat cncrete w-permeabt
n cntact wth a tn ate, cntnn
reactn depend n a renewabe rce be
ate. i there tte r n water mvement (e
tatc water tabe), the rate repenhment dted
at rm the rrndn w be w, a w be
the rate rmatn reactn prdct; the attack
w therere be mted. Mre deta can be nd n
As 3735 and the ppementar cmmentar10.
The ate retance bred cncrete ha been
nvetated extenve bth n Atraa and
verea; ndn ncde recmmendatn r
prtectn meare (e cnttent, mx den).
The mprtance addren qat e ch
a cmpactn and crn are a hhhted a
the have a majr nfence n the permeabt, and
hence drabt cncrete n thee cndtn. Mre
nrmatn can be nd n stark11 and Harrn12.
Partcar ate n can a ead t
hh acdc cndtn (acd-ate ).
Whe the recmmendatn n th gde w
a at n thee cndtn, mre-pecc
recmmendatn r expre t thee
envrnment are bend the cpe th
dcment and can be nd n BRE Det 3639.
4.4 CorrosionoReinorcement
4.4.1General
The cncrete rrndn renrcement prvde a
hh akane envrnment (pH arnd 12) whch
ret n the tee ben prtected b the rmatn
a hh mpermeabe xde aer n t race. Th
eectve prtect the tee rm crrn, even n
the preence mtre and xen.
The cncrete cver t the renrcement prvde a
phca barrer aant the nre btance
ch a at. genera, a the evert the
expre ncreae, w the reqred qat the
cncrete cver.
There are tw man mechanm b whch the
prtectn the tee can be mpared and crrn
ntated:
n Redctn n the akant the cncrete whch
prevent the prtectve xde aer rmn
n
inre at ch a chrde whch, preentn cent cncentratn, w cae crrn
even n an akane envrnment.
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4.4.2Reductioninthealkalinityoconcrete
Redctn n the akant r pH eve the cncrete
can ccr thrh the prcee carbnatn r
eachn. Carbnatn a prce where cacm
hdrxde n the cncrete react wth carbn dxde
rm the atmphere t rm e-akane prdct;
eachn nvve the remva be aka
hdrxde (hh pH) rm wthn the cncrete.
Becae carbnatn reqre cntact wth the ar,
t nke t cae crrn prbem n ab
and tn bred n the rnd, partcar n
mt envrnment. leachn a nke t
cae prbem a the fw water thrh the
and acr the race a bred ab r tn
enera ncent t remve r 'wah t' an
be aka. in acdc , eachn akae
pbe.
Th the man actr can crrn renrce-
ment n ab and tn the nre at.
4.4.3Ingressosalts
Chrde-ndced crrn tend t be acated
wth ntene caed attack the renrcement.
Reerrn t Table3, the hhet n cncentratn
that chrde, and t thee be chrde
n that rada penetrate nt the cncrete andcae crrn the renrcement. When the
cncentratn chrde n at the tee reache a
certan eve, a breakdwn n the pave xde m
arnd the tee ccr, even nder cndtn
hh akant, can the tee t be actvated, and
crrn t be ntated. in the preence mtre
and xen, crrn cntne r prpaate,
wth pan the cncrete takn pace nce the
expanve rce caed b the rt exceed the
tene capact the cncrete.
Fr crrn renrcement t be ntated and
t cntne, three majr cndtn mt ext
mtane, vz the preence at (e
chrde), mtre and xen. it enera
areed that n a cntn bmered tatn,
crrn renrcement nebe de t the ack
xen, the dn at thrh the atrated
pre the cncrete ben w and, n me cae,
the pre becmn bcked wth nbe prdct.
in zne that are bjected t repeated wettn and
drn, ane water ma be drawn thrh the pre
the cncrete b capar actn.
4.4.4Cracking
Crackn n an cncrete eement ma mpact n
the cncrete drabt becae t prvde a drect
paae r mtre (pb cntann areve
aent ch a at) and xen t enter the
cncrete. Dependn n ther depth and wdth, and
the arevene the expre cndtn, ear
crrn the renrcement ma ccr, can
caed are and pan.
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5.1 General
in rban area, ant manaement tratee can
ether be n a brad cae, nvvn are area
and ch a a bdvn, r n a caed cae
ch a a ne-t devepment. Whe the tratee
t dea wth ant e var cnderab between
bdvn and ne-t devepment, n term
n cncrete n ane envrnment, the ame
prncpe app t bth ae the deree
expre and prvde an apprprate cncrete
trenth and cver.
5.2 Subdivisions
The devepment bdvn ha the ptenta t
ater an extn ant n a brad cae, ncdn
the n adjacent prperte and devepment.
Chann the andrm, varn the veetatn nrechare and dchare area, tn nratrctre
and ervce, and e re water, can a aect
the rndwater and/r ant eve. Whe the
hrt-term mpact ma be ar accrate aeed,
predctn the na tcme rbanatn ver, a,
a t-ear perd ar mre dct, de t the man
varabe nvved (ee sectn 2.3).
i nvetatn revea n extn r ptenta ant
prbem, then wrk can prceed nrma. Hwever,
an extn r ptenta prbem dented, the
wn hd be cndered:
n Saltloading. grndwater (cntann at) w
fw dwnward, and ma emere n w-n
area ch a creek and rver, r at the bae
a pe. i rndwater ntercepted an
the pe thrh actvte ch a ct-and-
cntrctn, prvn retann wa and
ntaatn rad/ervce, and dverted t
trmwater dran, a mar at adn hd
reach the creek/rver. Hwever, nterceptn
rndwater can create me pprtnte,
ncdn ben abe t dvert at t evapratnban, cntrn the heht the water tabe
and eachn at t the Figure1. The
ze the evapratn ban can be dened
t perrm adeqate r the majrt ht
ran hwer experenced n r cmate, whe n
heav dwnpr, at w be dted and fhedthrh the tem.
n Slabscaping. Th a term ed t decrbe the
cntrctn eve bdn bck b terracn
the pe a part the bdvn devepment.
Becae the qantt and ea acce drn
devepment, retann wa can be prvded at
a wer ct. Whe hn t w ct mre,
the avn ered t the hme wner thrh
ecnmca ab-n-rnd cntrctn nvvn
n ct-and- r retann wa ar tweh the
ncreae. in term rban ant, th d a-rnd tn r pn te, ha mar benet
t ndvda ct-and- cntrctn n ne
t, whe t aw reater cntr the dranae
e Figure2.
n Levels. The nhed race eve n bck
hd be prvded wth adeqate a t the
treet t aw rn water and prevent water
pndn, watern the , and t redce
the ntratn rana nt the rnd.
n Estatecut-and-ll. Whe th ma expe me
ane matera, cncrete eement ch a he
ab, dran and retann wa, and nratrctre,
can be dened t prvde the reqred drabt.
Dependn n the ant eve, the reatet
mpact ma be the hrt-term eect n the
veetatn ch a tree, awn and arden.
Care den the majr earthwrk hd be
abe t vercme mt thee prbem b, a,
keepn the ane matera cvered. Fr the n
term, the rnd eve and den the dranae
tem hd be abe t cntr the eve the
rndwater tabe. in th wa, an at preentnear the race hd be rada eached
rther dwn.
n Concreteretainingwalls. Adeqate dranae
hd be prvded behnd wa. in ane a
patc membrane behnd the wa w a at
wth redcn the rk efrecence n the
exped ace the wa. The wa hd have
apprprate cncrete trenth and cver t the
renrcement.
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n Stormwater/subsoildrains. Fr eve/w-n
area, trmwater dran an rad can be
ed t cntr rndwater eve, ee Figure3.
Dependn n the tatn, thee cd be
ntaed at reater depth t rther wer the
rndwater tabe. Aternatve, t redce the
dtance between dran, b dran cd be
ntaed an prpert bndare.
n Filling. i the eve a w-n area t be bt
p b n (wth nn-ane matera), a dranae
aer hd be prvded beneath the t prevent
rndwater rn t the race. Nte that th
aer hd be draned.
n Cappinglayers. Cvern ane wth a aer
nn-ane matera (perhap an mpermeabe ca
matera) ma be an ptn t avd dtrbance
the aected hrzn/matera, bt the n-
term eectvene need t be evaated. The
matera ma nterere wth the natra evapratn
prce and cae the rndwater eve t re
t the nderde the aer. Capar actn,
partcar n the tpe ca matera that
mht be ed a a cappn aer, ma then draw
the rndwater and at cer t the racewhere bdn eement and andcapn ma be
aected.
i there an extn ant prbem, then a
eement wthn the bdvn w need t be
dened t aw r th. The den the
bdvn hd a enabe an mprvement the
tatn ver tme (e redctn n the ant) thrh
prcedre ch a etate tree pantn and dranae
den t wer rndwater eve and aw eachn
the at.
Where there the ptenta r a ant hazard t
devep, the den prce hd ether arantee
that n tre prbem w are, r reqre that
certan bac meare are ncrprated nt the
den , a, he tn t enre ther drabt
the tatn chane. Nte that ch a arantee
ma be dct t er ver the tpca 50-ear den
e a bdn.
5.3 Single-lotDevelopments
The pprtnte t repnd t ant n ne-t
devepment are mted t n-te actn ch abdn and ervce den, trmwater manaement
and andcapn13. Hwever, the mpact n the vera
ant tem hd nt be nderetmated a each
ne t can cntrbte t the recharn the water
tabe.
in area aected b rban ant, me tem t
cnder are:
n Cutandll. The majrt pn te w be
ct-and-ed t create a eve bdn patrm.
Th ma expe me ane matera, n whch
cae the cncrete tn, retann wa and
pavn hd be dened t prvde the reqred
drabt.
n Suspendedfoors. Nte that the trp tn
ed t pprt pended fr are enera
deeper than the ede beam r tened-rat
tpe tn, and extend rther nt the rnd,
ncrean the rk expre t ane cndtn,
epeca there a hh rndwater tabe.
n Stripandpadootings. A a damp-prn
membrane edm prvded r trp r pad
tn, the cncrete r thee hd be
dened r the expre cndtn preent n
Retaining wall with subsoildrainage behind, drainingto evaporation basinor stormwater
Originalgroundwaterlevel
Newgroundwaterlevel
Groundwatertable lowered
Footings designedfor saline conditions
FIGURE1Ct-and- cntrctn
Retaining walls
with subsoil drainage behind,draining to evaporation basins or stormwater
House lot
House lot
House lot
FIGURE2sabcapn prvde cntr dranae
Drain interruptsgroundwater
Drain lowersgroundwaterlevel
Groundwater level Groundwater levelRoadway
FIGURE3strmwater dran cntr rndwater
eve
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the te. i a damp-prn membrane ntaed,
and a redced cncrete trenth and cver ed,
the member hd be cmpete encaed b the
membrane.
n Externalpaving. Where pavn (ncdn
drvewa) ben paced n ane , the
prvn a patc membrane ch a a damp-
prn membrane nder the pavn w at
n preventn at cmn thrh the pavn
matera. Thee at ma cae efrecence
and pbe phca, chemca and crrn
damae t pavn.
n Concreteretainingwalls. A r bdvn,
adeqate dranae hd be prvded behnd
cncrete retann wa. A patc membrane
behnd the wa w a redce the rk
efrecence and pbe phca damae t the
exped ace the wa. Cncrete retann wa
tem hd be dened wth the apprprate
cncrete trenth and cver t the renrcement.
n Drainage. grnd and pavn eve hd enre
that water de nt pnd n the prpert a the
ncreaed ntratn w rae the water tabe.
sb dran behnd retann wa and arnd
bdn, and dran at the bae batter hd
be eectve draned t avd water pndn
wthn the trenche/dran. Fr fat te, b
dranae can be ntaed t cntr the eve the
rndwater tabe.
n Landscaping. Pantn deep-rted veetatn w
at n cntrn the eve the water tabe b
redcn ntratn. Dependn n the ant eve,
at-retant tr and pant cd be cndered.
n Sundrybuildingsandretainingwalls. Fr tem
ch a arden hed and ma retann
wa, the reqred den e ma n be 10
t 20 ear, ntead the nmna 50 ear
reqred new he. in thee crcmtance,
the nrma 20-MPa cncrete trenth ma be
atactr. in ane envrnment, t , hwever,
t recmmended that the cncrete be paced n
a membrane ch a a vapr barrer t cntr
mtre and efrecence rm the at.
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6.1 General
Th ectn prvde recmmendatn n cncrete
trenth, cver t the renrcement, cmpactn and
crn tether wth meare t cntr crackn
t enre drabt cncrete ab and tn
exped t rban ant.
The recmmendatn n th ectn take accnt
the reevant reqrement n nt n As 2870
Residential Slabs and Footings14bt a n As 3600
Concrete Structures15, AS 2159 Piling Design
and Installation16, As 3735 Concrete Structures or
Retaining Liquidsand the Cmmentar10 n t, and n
the Bdn Cde Atraa17. A are baed n a
den e 4060 ear.
Crrent the BCA and standard reqre the e
a mnmm 20-MPa cncrete r redenta ab
and tn, rearde the ant the , n
the ba that adeqate prtectn ered b the
damp-prn membrane, a t ate the cncrete
eement rm t rrndn. it mpe that crrect
ntaatn and mantenance the membrane can be
aranteed. A, there are n reqrement r trp
and pad tn the wrappn whch n a damp-
prn membrane mpractca.
A mre practca tn t prvde the apprprate
cncrete trenth and cver r the rban ant
expre cndtn preent n the te. Fr ab-
n-rnd cntrctn, the patc membrane,
apart rm n t prmar nctn cntrn
water vapr rn thrh the ab, can then be
rearded a an addtna aeard ( ntaed
crrect), and ne whch w rther ncreae the
den e the cncrete eement. Th apprach
appe partcar t trp and pad tn where n
pecc reqrement r prtectn are prvded n
the standard.
6.2 Concrete
6.2.1Quality
The permeabt cncrete prbab the mt
mprtant actr aectn t drabt nce t wdetermne the deree penetratn areve
aent rm the envrnment. Cncrete hh
permeabt w aw the penetratn at,
mtre and xen, eadn t the deterratn
mechanm ( bth the cncrete and an
embedded tee) dced earer.
Cncrete permeabt, n trn, nfenced b
nmer actr, the mt ncant ben
the water-cement rat and the enth tme r
whch the cncrete cred. The cement cntent
an mprtant actr n prdcn a cheve
and wrkabe mx, th actatn pacn and
cmpactn t prdce a dene cncrete.
it hd be recned that cncrete permeabt
cntred b actr whch are aed t the cncrete'
trenth, e water-cement rat, cement cntent
and deree hdratn/crn. A a ret, and
a becae t the mt cnvenent methd
peccatn and cntr, the trenth cncrete
the cmmn meare t qat.
6.2.2Strength
Adptn the a phph pecn drabt
n term cncrete trenth and cver, Table4
ve the recmmended Nrma rade cncrete
trenth (e N20) r the var ant cae.
Thee are the tandard trenth rade cncrete
manactred b read mxed pper t cmp
wth the reqrement As 137918.
Nte that whe the e an arbtrar ECe
vae r
determnn the mpact ant n bdn and
nratrctre a mpcatn, r cncrete drabt
where the derence n trenth between the tandard
cncrete trenth rade abt 25% (e 20 MPa,
25 MPa, 32 MPa, 40 MPa, etc), the mpact ma
varatn n the ECe
n the eectn the
apprprate cncrete trenth mnma.
in sectn 3.6, t wa hwn that ane are
enera rearded a the wth ECe
vae reater
than 4 ds/m. Therere, bth the nn-ane and
ht ane cae wd be rearded a nn-
areve n term cncrete drabt, wth
an N20 cncrete ben atactr.
Recmmended mnmm cncrete trenth r theant cae dented n Table2 are hwn
n Table4.
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TABLE4 Recmmended cncrete trenth r
ant cae
ECerange Salinityclass
(ds/m) (rm Tabe 2) Concretegrade
16 Hh ane N40
Nte that the cncrete trenth ven n Table4
are a de r ane cndtn, and ma nt be
adeqate n hh acdc . At Waa Waa,tetn reveaed the rndwater rm a bre t
have netra t ht akane pH vae, n
prbem wth acd deterratn wd be expected.
At secnd Pnd Creek, pH vae the 1:5
extract raned rm abt 5 t 9. in As 2159 th
cndered a nn-areve n w-permeabt
ch a t and ca, and reqre a mnmm
25-MPa cncrete r drabt the cncrete te.
Fr hh permeabe ch a and where the
rndwater at the race the cncrete can be
repenhed mre ea, the envrnment wd becndered md areve and reqre a mnmm
32-MPa cncrete trenth r drabt. Nte that n
th ntance thee cncrete trenth are cntent
wth the reqred r drabt aant chrde and
ate n.
6.2.3Covertoreinorcement
in addtn t the chemca prtectn arded t
the renrcn tee b the akant the cncrete,
the cncrete cver t renrcement prvde a a
phca barrer t the nre areve aent.
The eectvene th barrer depend n bth t
thckne and t qat. Th, adeqate cver
d qat cncrete vta n prvdn drabe
cncrete n areve cndtn.
Recmmended cver t renrcement are:
n sab and nterna beam prtected b a damp-
prn membrane
T nterna race 20 mm
T membrane n cntact
wth the rnd 30 mm
n Permeter beam/trp tn nt prtected b a
damp-prn membrane
Nn-areve 40 mm
Mderate ane 45 mm
Ver ane 50 mm
Hh ane 55 mm
The recmmended cver r ab and nterna
beam prtected b a membrane cmp wth the
reqrement As 2870. Fr permeter beam
arnd tened rat and trp r pad tn where
the cncrete ma nt be prtected b a tabe
membrane, ncrean the cver recmmended.
6.2.4Materials
Cncrete baca a cmbnatn cement,areate (ne and care) and water. Admxtre
and ther nredent are ten added t mpart
partcar prperte t the cncrete n the reh r
hardened tate.
it mprtant t enre that cncrete manactred
and pped n accrdance wth As 1379, a th w
enre that the nredent have a been checked
r cmpance wth the reqrement the reevant
Atraan standard.
6.2.5Uncontrolledwateraddition
The mprtance nt addn mre than the peced
amnt water cannt be veremphaed. A water
added t the cncrete mx, the water-cement rat
ncreaed, retn n wer trenth and mre
permeabe cncrete that e abe t ret the
phca damae t ma be bjected t n a ane
envrnment, ee Figures4and5.
A a enera re, the mre water that added, the
mre permeabe the cncrete w be, and hence the
e drabe. A, exce water ma ncreae drn
hrnkae crackn and prdce a weaker raceprne t exceve wear and dtn.
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6.3 Reinorcement
6.3.1Fixingoreinorcement
Renrcement hd be xed n ptn t prevent
mvement drn pacn the cncrete and tprvde the reqred cncrete cver. Cmprehenve
nrmatn can be nd n Guide to Concrete
Construction19.
6.3.2Alternativematerials
optn r an extended den e ncde the e
avaned, tane tee and epx cated
renrcement. Fr redenta ab and tn, the
ct the atter tw ptn ma be prhbtve; a
mre practca and ct-eectve apprach enera
t ncreae the cncrete trenth and/r cver.
6.4 Concreting
6.4.1General
The three majr phae cncretn are pacn,
cmpactn and crn. Each ha a ncantnfence n the qat the retn cncrete and,
n partcar n t abt t perrm atactr n
ane envrnment. sme the mre mprtant
apect thee te practce are tned here; a
cmprehenve cverae a acet cncretn
wrk prvded n Guide to Concrete Construction.
6.4.2Placingandcompacting
Cncrete hd be paced t avd ereatn
and hnecmbn the mx, a pr cncrete
w prvde an neectve cncrete cver t prtect
the renrcement. An water r debr n the bae
per, tn and thckenn hd be remved
prr t pacn the cncrete t avd prbem wth
ncrean water-cement rat, ereatn r wahn
t cement pate rm the areate, a whch
can aect the drabt the cncrete.
Cmpactn the cncrete ver mprtant a
t expe entrapped ar and pack the areate
partce tether a t ncreae the dent
the cncrete. it enhance the tmate trenth
the cncrete and the bnd wth the renrcement. it
a ncreae the cncrete' abran retance,
decreae t permeabt and therere enhance t
enera drabt.
Prper cmpactn a enre that the rmwrk
cmpete ed e there are n pcket
hnecmbed matera and that the reqred nh
btaned n vertca race.
When rt paced, nrma cncrete w cntan
between 5% and 20% b vme entrapped ar.
The areate partce, athh cated wth mrtar,
tend t arch aant ne anther and are prevented
rm mpn r cndatn b nterna rctn.
Cmpactn cncrete therere a tw-tae
prce. Frt the areate partce are et n
mtn and mp t the rm, vn a eve
tp race. in the ecnd tae, entrapped ar
expeed, ee Figure6.
it mprtant t recne the tw tae n the
cmpactn prce becae, wth vbratn, nta
cndatn the cncrete can ten be acheved
reatve qck. The cncrete qee and the
race becme eve, vn the mpren thatthe cncrete cmpacted. Entrapped ar take a
COMPRESSIVE STRENGTH (MPa)
10
20
30
60
50
40
0
70
WATER TO CEMENT RATIO
0.3 0.6 0.70.4 0.5
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8WATER TO CEMENT RATIO
0
20
40
60
80
100
120
140
COEFFICIENT OF PERMEABILITY (10-14m/s)
FIGURE4 Tpca eect water/cement rat n
trenth
FIGURE5The eect water-cement rat n the
permeabt the cncrete
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tte ner t re t the race. Cmpactn mt
therere be prned nt th accmphed, e
nt ar bbbe n ner appear n the race.
A can be een rm Figure7, the eect
cmpactn n cmpreve trenth dramatc. Fr
exampe, the trenth cncrete cntann 10%
entrapped ar ma be a tte a 50% that the
cncrete when cmpacted.
Permeabt ma be mar aected nce
cmpactn, n addtn t expen entrapped ar,
prmte a mre even dtrbtn pre wthn the
cncrete, can them t becme dcntn.
The drabt the cncrete th mprved.
Whe the deeper trp tn and beam wthn
ab n rnd (bth ede and nterna) hd be
cmpacted n an mmern vbratr, r 100-mm-
thck ab n rnd, adeqate cmpactn can
a be acheved thrh the pacn, creedn
and nhn prcee. smetme, race vbratn
w be ed n the rm a ma hand-hed vbratn
creed. immern vbratr are nt recmmended
r a 100-mm-thck ab n rnd, a the ab depth
de nt aw prper mmern the vbratr head,
and damae ma be caed t the vapr/damp-
prn membrane.
The prper cmpactn cncrete eenta t the
drabt cncrete n ane envrnment.
6.4.3Curing
Crn the prce that cntr the
mtre rm cncrete ater t ha been paced
n ptn (r drn the manactre cncrete
prdct), thereb prvdn tme r cmpete
hdratn the cement t ccr. snce the hdratn
cement take tme da, and even week
rather than hr crn mt be ndertaken r a
reanabe perd tme the cncrete t achevet ptenta trenth and drabt. Crn ma a
encmpa the cntr temperatre nce th
aect the rate at whch cement hdrate.
Figure8 trate the mprtance crn b
cmparn the trenth (at 180 da) cncrete
whch ha been:
n kept mt r 180 da;
n kept mt r var perd tme and then
awed t dr t; and
n awed t dr t rm the tme t wa rt made.
A demntrated b Figure8, cncrete awed t
dr t mmedate acheve n 40% the trenth
the ame cncrete water cred r the perd
180 da. Even three da water crn ncreae
th re t mre than 60%, wht 28 da water
crn ncreae t t abt 95%. Keepn cncrete
mt therere a ver eectve wa ncrean t
tmate trenth.
RELATIVE STRENGTH (%)
AIR VOIDS (%)
0
20
40
60
80
0
15 20 25 30
100
5 10
FIGURE7l trenth thrh ncmpete
cmpactn
COMPRESSIVE STRENGTH AT 180 DAYSAS % OF CONTINUOUSLY MOIST SAMPLE
Days cured (then in air)
20
40
60
80
0Contin-uouslymoist
28 14 7 3
100
Contin-uouslyin air
FIGURE8Eect dratn water crn n the
trenth cncrete
STAGE 1STAGE 1
PROCESS: Liquefaction of theconcrete which
allows it to slumpand fill the form
TIME: 3 to 5 seconds
STAGE 2STAGE 2
PROCESS: The expulsion ofentrapped air
TIME: 7 to 15 seconds
TOTAL TIME (for both stages of the process): 10 to 20 secondsTOTAL TIME (for both stages of the process): 10 to 20 seconds
FIGURE6The prce cmpactn
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Guide to Residential Slabs and Footings in Saline Environments 1
The crn perd w depend n the prperte
reqred the cncrete, the prpe r whch t
t be ed, and the ambent cndtn, e the
temperatre and reatve hmdt the rrndn
atmphere.
Keepn cncrete mt b preventn the
mtre can be acheved b ether:
n preventn an exceve mtre b
eavn rmwrk n pace, cvern the cncrete
wth an mpermeabe membrane ater the rmwrk
ha been remved (e patc heetn, chemca
crn cmpnd), pacement aant a patc
membrane, r b a cmbnatn ch methd;
r
n cntn wettn the exped race thereb
preventn the mtre rm t (pndn
r pran the race wth water are tpca
methd ed).
The drabt cncrete aected b a nmber
actr ncdn t permeabt and abrptvt.
Brad peakn, thee are reated t the prt
the cncrete and whether the pre and capare
are dcrete r ntercnnected. Wht the nmber and
ze pre n cement pate are reated drect t
t water-cement rat, the are a reated, ndrect,
t the extent water crn. over tme, water crn
cae hdratn prdct t (ether parta r
cmpete) the pre and capare preent, and
hence t redce the prt the pate.
Figure9 trate the eect derent perd
water crn n the permeabt cement pate. A
can be een, extendn the crn perd redce the
permeabt.
in ane envrnment, a weak cncrete race
e eectve n retn bth phca attack rm
at and chemca attack rm ate, and the
ncreaed permeabt the cncrete prvde ae eectve barrer t the nre areve
btance ch a chrde n. The cncrete cver
prvded therere nt a eectve a that amed
n the reqrement the standard, and the den
e ma be redced.
Nte that t mprtant t cre a exped ace
the cncrete, ncdn the ede, a thee enera
have the reatet expre t an areve
btance n the .
The prper crn cncrete anther eenta
eement n the drabt cncrete n aneenvrnment.
Recmmended crn perd are:
n sab srace
interr 3 da
Exterr 7 da
n sab Ede
Nn-areve r ane 7 da
6.5 ControloCracking
Whe crack are nt nrma a trctra prbem
n he ab, wde enh, the ma aw
the nre at and aect the drabt thecncrete n ane envrnment.
There are man wa t redce the tendenc r the
cncrete t crack. Fr nrma ca cncrete, the
mpet t enre that n exce water added
n te and the cncrete adeqate cmpacted.
Awn the cncrete t an trenth that t
better abe t ret the tene rce that cae
crackn, can a be addreed thrh prper
crn the cncrete. Crn nt n aw the
chemca reactn repnbe r trenth an t
take pace, bt a dea the drn the cncrete.The ncreaed trenth an prr t drn w redce
the tendenc the cncrete t crack.
Mre renrcement a a mpe and reatve
nexpenve wa t cntr the ze crack.
increan the amnt ab renrcement b
pecn a heaver abrc (e sl92 ntead sl72)
w tend t dtrbte an crackn mre even.
Pacn extra renrcement at pnt where hrnkae
crackn expected (e trmmer bar at re-entrant
crner and pecn verap ab abrc n
narrw part the ab t ret n dbe the amnt abrc n the crtca area) a eectve.
COEFFICIENT OF PERMEABILITY (m/s)
CURING PERIOD (days)
Cement paste (W/C = 0.51)
0
10-8
10-9
10-10
10-11
10-12
10-13
10-14
10-15
10-16
10-7
1 3 7 14 28 90
10-17
FIGURE9Eect dratn water crn n the
permeabt cement pate
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0 Guide to Residential Slabs and Footings in Saline Environments
6.6 Damp-proofngMembrane
The ntaatn a damp-prn membrane
atn the reqrement As 2870
recmmended r ab-n-rnd cntrctn; t
mandatr n me state. Th hd be ad n a
mnmm 20-mm and aer t mnme the rk
pnctrn the membrane and t prvde a phca
break/barrer t pward mvement rndwater.
other reqrement As 2870 are:
n The entre ab nderad.
n The membrane apped 200 mm at jnt r
cntnt.
n The membrane cntn at penetratn;
taped r eaed wth a ce-ttn eeve.
n The membrane extended t rnd eve.
Nte that whe damp-prn membrane can be
ed r trp and pad tn, prtectn the tp
race (a bew rnd eve) ma be dct.
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1 oFahert K Local Government Salinity Initiative
Broad Scale Resources or Urban Salinity
AssessmentDepartment land and Water
Cnervatn sdne, 2002.
2 Rament g E and Hnn F R Australian
Laboratory Handbook o Soil and Water
Chemical Methodsinkata Pre, Mebrne,
1992.
3 Abbtt T s Soil Test InterpretationPrceedn
a smpm, Dbb, NsW, Febrar 1990.
4 shaw R J s sant, n Identifcation o Soils
and Interpretation o Soil Data, pp 145174, the
Atraan scet s scence incrprated,
Qeenand Branch, Brbane, 1985.
5 lcrap A and Mcghe s Local Government
Salinity Initiative Site Investigation or UrbanSalinityDepartment land and Water
Cnervatn, sdne, 2002.
6 Rchard l A Diagnosis and Improvement o
Saline and Alkaline SoilsusDA Handbk N 60,
Wahntn DC, 1954.
7 Urban Salinity Annual Status Report 19992000
Waa Waa Ct Cnc.
8 Cx J, Ftzpatrck R, Wam B, Dave P and
Frreter s Salinity Investigation at Second
Ponds CreekCntanc reprt r Re H
inratrctre Pt ltd, J 2002.
9 Sulate and acid resistance o concrete in the
groundBRE Det 363, Bdn Reearch
Etabhment, uK 1996.
10 As 3735 Concrete structures or retaining liquids
standard Atraa, 2001.
As 3735 spp1, Concrete structures or
retaining liquids Commentary, standard
Atraa, 2001.
11 stark D, Longtime Study o Concrete Durability
in Sulate SoilsPrtand Cement Acatn,
Reearch and Devepment Betn RD086.01T.
12 Harrn W H Sulate Resistance o Buried
ConcreteThe thrd reprt n a n-term
nvetatn at Nrthwck Park and n mar
cncrete n ate tn at BRE Bdn
Reearch Etabhment Reprt Ci/sB q2(R8),1992.
13 Wetern sdne sant Wrkn Part, Western
Sydney Salinity Code o Practice, Wetern
sdne Rena oranatn Cnc, 2003.
14 As 2870 Residential slabs and ootings
Constructionstandard Atraa, 1996.
15 As 3600 Concrete structuresstandard
Atraa, 2001.
16 As 2159 Piling Design and installation
standard Atraa, 1995.
17 Bdn Cde Atraa 2004 Housing
Provisions(BCA 2004 Vme Tw) Atraan
Bdn Cde Bard, 2004.
18 As 1379 Specifcation and supply o concrete,
standard Atraa, 1997
19 Guide to Concrete Construction(T41/HB64)
Cement and Cncrete Acatn Atraa
and standard Atraa, 2002
CementConcrete&AggregatesAustraliawebte:
www.concrete.net.au
O
Reerences