Comparative Study of Strength and Corrosion Resistant...

Research ArticleComparative Study of Strength and Corrosion ResistantProperties of Plain and Blended Cement Concrete Types

Velu Saraswathy12 Subbiah Karthick13 Han Seung Lee1

Seung-Jun Kwon4 and Hyun-Min Yang1

1Department of Architectural Engineering Hanyang University 1271 Sa 3-dong Sangrok-gu Ansan 426791 Republic of Korea2Corrosion andMaterials Protection Division CSIR-Central Electrochemical Research Institute Karaikudi Tamil Nadu 630003 India3PG and Research Department of Chemistry Alagappa Government Arts College Karaikudi Tamil Nadu 630003 India4Department of Civil Engineering Hannam University Daejeon 306-791 Republic of Korea

Correspondence should be addressed to Seung-Jun Kwon jjuni98hannamackr

Received 29 May 2017 Accepted 31 July 2017 Published 4 October 2017

Academic Editor Michael J Schutze

Copyright copy 2017 Velu Saraswathy et alThis is an open access article distributed under theCreativeCommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The relative performances of mechanical permeability and corrosion resistance properties of different concrete types werecompared Concrete types were made from ordinary Portland cement (OPC) Portland pozzolana cement (PPC) and Portland slagcement (PSC) Compressive strength test effective porosity test coefficient of water absorption short-term accelerated impressedvoltage test and rapid chloride permeability test (RCPT) were conducted onM30 andM40 grades of concrete designed with OPCPPC and PSC cements for 28- and 90-day cured concrete types Long-term studies such asmicrocell and electrochemical evaluationwere carried out to understand the corrosion behaviour of rebar embedded in different concrete types Better corrosion resistantproperties were observed for PSC concrete by showing a minimum current flow lowest free chloride contents and lesser porosityBesides PSC concrete has shown less coefficient of water absorption chloride diffusion coefficient (CDC) and lower corrosion rateand thereby the time taken for initiation of crack extended

1 Introduction

Reinforced concrete is protected from corrosion due to thehigh alkalinity existing in the concrete environment andthe cover concrete which acts as a protective barrier to theaccess of chloride ions Apart from this reinforced concretestructures when exposed to severe marine environments leadto the premature failure of the structures [1] Corrosion ofembedded steel in concrete is one of the major causes ofpremature deterioration of concrete structures which affectsthe service life of the important structures in the chlorideprone environment [2] Therefore the chloride permeabilityplays a significant role in determining the service life of themajor infrastructures [3] Due to the heterogeneous natureof the concrete chloride ions enter the pores and attack theembedded steel in concrete causing cracking and spallingof the cover concrete portion and exposing the steel rein-forcement when it is exposed to the marine environment [4]

Hence to enhance the durability of the structures wastematerials like fly ash rice husk ash slag and other pozzolanicmaterials are being used in the construction industry notonly from the durability point of view but also to reduce thegreenhouse gas emission and to save the environment [5]The use of supplementary cementitious materials (SCM) andtheir effectiveness in making the blended cement concreteare well debated in the literature [6ndash12] The composition ofSCM may vary from source to source from which they arecollected because the nature of the source depends upon therawmaterials used formaking themanufacturing process andthe geographical conditions [13]

Curing plays a major role in affecting the strengthand permeability characteristics of the concrete structuresMainly while using supplementary cementitious materialscare should be taken for continuous curing of the structuresin the initial stages since hydration reactions are slow in usingpozzolanic materials The other factors which influence the

HindawiAdvances in Materials Science and EngineeringVolume 2017 Article ID 9454982 14 pageshttpsdoiorg10115520179454982

2 Advances in Materials Science and Engineering

strength characteristics are fineness modulus water-cementratio (wc) chemical composition and so on [14 15] Manyresearchers have discussed the different types of curingpore structure refinement and permeability characteristics ofblended cements by using fly ash slag silica fume and soon [16ndash19] The results indicated that blended cement withlonger duration has shown strength and other propertiesequal to those of ordinary Portland cement It is also reportedthat blended cements enhanced the workability durabilityandmechanical properties of the concrete [20ndash24] So far thestudies have focused on the particular aspect of corrosion likepermeability pore structure chloride ingress or physical andchemical characteristics by either short-term or long-termstudies

Hence the aim of the present investigation is to evaluatethe corrosion resistant properties of rich and lean mixconcrete made from Portland pozzolana cement (PPC) andPortland slag cement (PSC) under accelerated and nor-mal exposure conditions The results were compared withordinary Portland cement (OPC) concrete Further in thisinvestigation two curing periods two grades of concreteand two different exposure conditions namely normal andaccelerated exposure conditions were carried out In additionto these short-term and long-term tests porosity and perme-ability studies and mechanical and electrochemical studieswere also carried out for plain and blended cements and theresults were presented in a detailed manner

2 Experimental

21 Materials and Mix Proportions Two mix proportionshaving characteristic compressive strength of 30 and 40MPa concrete types were used for casting the concretespecimens The details of concrete mix proportions are givenin Table 1Three cements namely 43 grade ordinary Portlandcement conforming to IS8112 [25] (equivalent to ASTM-Type I cement) Portland pozzolana cement conforming toIS1489ndashPart-I [26] and Portland slag cement conformingto IS455 [27] were used Chemical composition of cementsused is given in Table 2 Graded river sand passing through118mm sieve with a fineness modulus of 285 and a specificgravity of 255 was used as fine aggregate Locally availablewell graded aggregates of normal size greater than 475mmand less than 20 mm having a fineness modulus of 272were used as coarse aggregates The specific gravity of thefine aggregate used was 278 Thermomechanically treated(TMT) rebar (Fe-415 grade) of 12mm diameter conformingto IS1786 [28] was used Potable water was used for castingthe concrete

22 Methods

221 Compressive Strength Compressive strength test wascarried out in concrete cubes of size 150 times 150 times 150mmusing 1 18 369 mix with wc ratio of 055 (M30 grade) and1 118 336 with wc ratio 045 (M40 grade) using OPC andblended cements (PPC and PSC) During casting themouldswere mechanically vibrated After 24 hours the specimens

Concretespecimen

Sides sealedwith epoxy resin

Shallow pan of water

100 mm

5mm

100

mm

Figure 1 Schematic of coefficient of water absorption test

were removed from the mould and subjected to water curingfor 28 and 90 days After a specified period of curing thespecimens were tested for compressive strength using AIMILcompression testing machine of 2000 kN capacity at a rateof loading of 210 kNmin The tests were carried out on sixspecimens and the average compressive strength values wererecorded for OPC PPC and PSC concrete types

222 Effective Porosity Test Percentage of water absorptionis a measure of the pore volume or porosity in hardenedconcrete which is occupied by water in saturated conditionWater absorption test was carried out as per ASTM C642-97[29] The effective porosity for OPC PPC and PSC concretetypes is calculated as follows

Effective porosity () = (119861 minus 119860)119881 times 100 (1)

where 119860 is mass of oven dried sample in air 119861 is saturatedmass of the surface dry sample in air after immersion and 119881is bulk volume of the sample

223 Coefficient of Water Absorption Coefficient of waterabsorption is suggested as ameasure of permeability of waterThis ismeasured by the rate of uptake ofwater by dry concreteover a period of 1 h The concrete cube specimens of 100 times100 times 100mm were preconditioned by drying in an oven at105∘C for 48 hrs until constant weight was reached and thenallowed to cool in an airtight sealed container for 3 days Thesides of the concrete samples were coated with transparentepoxy resin to allow the flow of water in unidirectionThen the samples were kept in a vertical position partiallyimmersed up to a depth of 5mm at one end while the restof the portions were kept exposed to the atmosphere asshown in Figure 1 The quantity of water absorbed during thefirst 60min was calculated Coefficients of water absorptionvalues for OPC PPC and PSC concrete specimens after 28and 90 days of moisture curing were determined using theformula [29]

119870119886= (119876119860)

2

times 1119905 (2)

where 119870119886is the coefficient of water absorption (m2sminus1) 119876 is

the quantity of water absorbed (m3) by the oven dry specimen

Advances in Materials Science and Engineering 3

Table 1 Details of concrete mix proportions

Grade Type of cement WC ratio Cement(kgmminus3)

Fineaggregate(kgmminus3)

Coarseaggregate(kgmminus3)

Water(kgmminus3)

M30OPC 055 338 607 1247 186PPC 055 338 607 1247 186PSC 055 338 607 1247 186

M40OPC 045 400 472 1247 180PPC 045 400 472 1247 180PSC 045 400 472 1247 180

Table 2 Chemical composition of cements

Constituent Weight()OPC PPC PSC

SiO2

210 320 310Al2O3

550 100 105Fe2O3

460 550 280CaO 630 440 470MgO 060 150 390SO3

260 260 260LOI 270 440 270

in time (119905) 119905 is 3600 s and 119860 is the surface area (m2) ofconcrete specimen through which water penetrates

224 Impressed Voltage Test Cylindrical concrete specimensof size 50mm diameter and 100mm height were cast usingM30 andM40 grades of concrete types Rebar types of 12mmdiameter and 100mm height were embedded centrally intothe concrete specimens During casting the moulds weremechanically vibrated After 24 h the cylindrical concretespecimens were demoulded and cured for 28 and 90 daysThen the specimens were subjected to impressed voltage testIn this technique the concrete specimens were immersed in5 NaCl solution and embedded steel in concrete is madeas anode with respect to an external stainless steel electrodeserving as the cathode by applying a constant positive poten-tial of 12 V to the system from a DC source The variationof current is recorded with time For each specimen thetime taken for initial crack and the corresponding maximumanodic current flow was recorded [30]

At the end of the 12V impressed voltage test the embed-ded steel specimens were broken and the sections were opencleaned in pickling solution (concentrated HCl containing20 gL of stannous chloride and 15 gL of antimony trioxide)then cleaned in distilled water dried and weighed as perASTM G1-03 [31] From the initial weight the loss in weightof embedded steel due to accelerated corrosion in OPC PPCand PSC concrete types was calculated From the weightloss data corrosion rate in mmpy was calculated using thefollowing equation [2]

Corrosion rate = 876 times ( 119882119863 times 119860 times 119879) (3)

where119882 is the weight loss in milligram 119863 is the density ofthe material used gcc 119860 is the area of the specimen (cm2)and 119879 is the duration of the test period in hours

225 Rapid Chloride Ion Permeability Test (RCPT) Theresistance to chloride ion penetration in terms of total chargethat passed in coulombs through OPC and blended concretespecimens after 28 and 90 days of moisture curing wasmeasured as per ASTMC1202-12 [32] A concrete disc of size100mm diameter and 50mm thickness was cast and allowedto cure for 28 and 90 daysThen the concrete specimens weresubjected to the RCPT by impressing 60V between two TSIAelectrodes Two halves of the specimens were sealed withPVC container of 95mm diameter One side of the containeris filled with 3 NaCl solution (that side of the cell will beconnected to the negative terminal of the power supply) theother side is filled with 03N NaOH solution (which willbe connected to the positive terminal of the power supply)Current flow is measured at every 30min up to 6 h From theresults using the current and time chloride permeability iscalculated in terms of coulombs at the end of 6 h

226 Chloride Diffusion Coefficient The amount of chlorideion migrating through the concrete specimens after 28 and90 days of curing was monitored by removing small amountof solution and determining the chloride concentration ofthese samples after 120 h Chloride diffusion coefficients werecalculated using NernstndashEinstein equation [33]

119863 = 1198691198771198791198711198851198651198620119864 (4)

where 119863 is the chloride diffusion coefficient (cm2s) 119869 isthe flux of chloride ions (molcm2s) 119877 is the gas constant(8314 JKmol)119879 is the absolute temperature (300K) 119871 is thethickness of the specimen (cm) 119885 is the valiancy of chlorideion (119885 = 1) 119865 is the Faradays constant (9648 times 104 JVmol)1198620is the initial chloride ion concentration (moll) and 119864 is

the applied potential (60V)

227 Potentiodynamic Polarization Method Concrete cubesof size 100 times 100 times 100mm that were cast with TMT rebarof 12mm diameter and 75mm length (two rebar types)were embedded at a cover depth of 25mm as shown inFigure 2 The cubes were cast for OPC PPC and PSC with


rebar

Connection wire

Concrete

100 mm

12 mm dia

25 mm cover25 mm cover

100mm

Figure 2 Schematic representation of concrete cube specimen usedfor potentiodynamic polarization and AC-impedance study

M30 and M40 grade concrete and allowed to cure for 90days After 90-day curing the specimens were exposed tothe open atmosphere under natural weathering conditionsAfter two years of exposure the embedded rebar types in theconcrete cube specimens were subjected to potentiodynamicpolarization technique using the three-electrode assemblyThe rebar embedded in concrete cube acts as a workingelectrode stainless steel electrode acts as a counter electrodeand Saturated Calomel Electrode (SCE) acts as a referenceelectrode From the polarization technique the corrosionkinetic parameters such as corrosion current (119868corr) corro-sion potential (119864corr) cathodic Tafel slope (119887

119888) and anodic

Tafel slope (119887119886) were obtained Both cathodic and anodic

polarization curveswere recorded potentiodynamically usingACM Instruments UK The potentiodynamic conditionscorrespond to a potential sweep rate of 01mVminminus1 andpotential ranges of +02V tominus02Vversus SCE from theOCPAll the experiments were carried out at the temperature of32 plusmn 1∘C

228 AC-Impedance Measurement The same cube speci-mens mentioned above were subjected to AC-impedancemeasurements The real part (1198851015840) and the imaginary part(minus11988510158401015840) of the cell impedance were measured for variousfrequencies (30 kHz to 001Hz) Plots of 1198851015840 versus minus11988510158401015840 weremade The same experimental setup was used here also

229 Macrocell Corrosion Studies A rectangular concrete(M40 grade) specimen of size 279mm times 152mm times 114mmwas designed as per ASTM G 109-07 [34] for macrocellcorrosion studies TMT rebar of 12mmdiameter and 300mmlength was used as both anode and cathode in the same con-crete The top mat of rebar acts as the anode and the bottommat of rebar acts as cathode The anode to cathode area ratiowas maintained as 1 2 to induce accelerated corrosion of theembedded anode The configuration of macrocell specimenis given in Figure 3 In both the anode and cathode 250mmlength was embedded inside the concrete and the remaininglength was used for taking electrical connections with properinsulations

The specimens were mechanically vibrated After 24hours of setting the specimens were demoulded and curedin distilled water for 90 days Then the specimens weresubjected to alternate wetting and drying cycles One cycle

consists of 15 days of wetting in 3 NaCl and 15 days ofdrying in open atmosphere Measurements were carried outduring the wetting cycle (15th day) as macrocell currentshowed maximum magnitude due to the low resistivity ofthe concrete All the concrete specimens were subjected to 24complete cycles of exposure period

3 Results and Discussion

31 Compressive Strength The compressive strength of OPCPPC and PSC concrete types after 28 and 90 days of curingfor M30 and M40 grades of concrete are given in Figures 4and 5 respectively

It was found from Figure 4 that in M30 grade concretethe 28-day strength obtained was 37MPa 355MPa and329MPa forOPC PPC and PSC concrete types respectivelyTherewas a slight increase in the 90-day compressive strengthvalues such as 40MPa for OPC 39MPa for PPC and369MPa for PSC respectively

On the other hand in M40 grade concrete (Figure 5)the 28-day strength obtained was 437MPa 412MPa and432MPa forOPC PPC and PSC concrete types respectivelyTherewas a slight increase in the 90-day compressive strengthvalues such as 477MPa for OPC 443MPa for PPC and468MPa for PSC respectively

The magnitude of increase in compressive strength from28 days to 90 days was found to be similar in M30 grade andM40 grade concrete types Comparable compressive strengthvalues were obtained for PPC and PSC concrete types whencompared with OPC concrete

32 Effective Porosity and Coefficient of Water AbsorptionEffective porosity and coefficient of water absorption valuescalculated for OPC PPC and PSC concrete types at 28- and90-day cured specimens were reported in Table 3 It wasobserved that both 28- and 90-day curedM30 andM40 gradeconcrete types showed the effective porosity and coefficient ofwater absorption in the decreasing order as follows OPC gtPPC gt PSC

Among the three types of concrete used PSC concreteshowed least pores and lower coefficient of water absorptionThe same trend is observed in both 28- and 90-day curedM30 and M40 grade concrete types For example in thecase of PSC 071 times 10minus7m2sminus1 and 062 times 10minus7m2sminus1 are thecoefficient of water absorption values obtained for 28-daycured M30 and M40 grade concrete respectively Similarlyfor M30 and M40 grade concrete types the coefficient ofwater absorption values obtained were 040 times 10minus7m2sminus1 and015 times 10minus7m2sminus1 for 90-day cured concrete respectivelyThe observed values of coefficient of water absorption wasattributed to the impermeability nature of the pore structurerefinement in PPC and PSC concrete typesThe improvementin the permeability characteristics of PPC and PSC is due tothe secondary hydration reaction


V

3 NaCl

Sealed withepoxy

PVC sheet

114 mm

rebarCathode 12 mm dia

rebarAnode 12 mm dia

75mm

75mm

25 mm

20 mm

114 mm

152mm107 mm

279mm

25 mm

20 mm

152

mm

Figure 3 Schematic view of macrocell specimen

Table 3 Permeability parameters for OPC PPC and PSC M30 and M40 grade concrete types

Grade Type of cement Effective porosity() Coefficient of waterabsorption(m2sminus1) times 10minus7

28 days 90 days 28 days 90 days

M30OPC 1515 1072 320 230PPC 1428 962 250 200PSC 1261 957 071 040

M40OPC 1328 943 300 190PPC 1242 679 290 110PSC 1061 632 062 015

In general the primary hydration reaction in concrete isas follows

2 (3CaO sdot SiO2) + 6H

2O

997888rarr 3CaO sdot 2SiO2sdot 3H2O + 3Ca (OH)2

(5)

But in PPC and PSC concrete types the additional secondaryhydration reaction is

3Ca (OH)2 + 2SiO2 +H2O 997888rarr 3CaO sdot 2SiO2 sdot 3H2O (6)

In PPC and PSC concrete types the Ca(OH)2content

reduction is due to the secondary hydration reaction Duringthe hydration in PPC lime is consumed but in OPC limeis produced This is the main advantage of using blendedcements to decrease the permeability of the concrete therebyincreasing the corrosion resistance properties [35]

33 Impressed Voltage Test The impressed voltage parame-ters of M30 and M40 grades of OPC PPC and PSC concrete

types under 28 and 90 days of curing time were given inTable 4 InM30 grade concrete themaximum anodic currentflow measured was found to be 77 65 and 43mA for OPCPPC and PSC concrete types respectively at 28-day curedspecimens The corresponding reduction in current flow wasobserved as 156 for PPC and 442 for PSC when com-pared to OPC These results clearly indicated that blendedcements namely PPC and PSC considerably decreased theanodic current flow Similar trendwas observed inM40 gradeconcrete Among the three concrete types the maximumreduction in current flowwas observed for PSC concreteThereason is that PSC cement consists of higher amount of Al

2O3

(105) when compared to OPC (55) and PPC (10)which interacted with Ca(OH)

2and favoured more C

3A and

C-S-H gel The formation of such compounds reduced themicro- and macropores present in the concrete and this isdue to the refinement of the microstructure considerablyreducing the current flow [36] After 90 days of curing OPCPPC and PSC concrete types showed only a slight decrease


Table 4 Impressed voltage parameters for rebar in OPC PPC and PSC M30 and M40 grade concrete types

Grade and typeof cement

Maximumanodic current

(mA)

()reduction

Time tocracking(days)

Free chloridecontents(ppm)

Weight loss(mg)

Reduction incorrosionrate ()

28-day cured concrete specimensOPC M30 77 mdash 07 4680 443210 mdashPPCM30 65 156 08 3560 253120 429PSC M30 43 442 10 3253 79140 821OPC M40 72 mdash 10 3789 353020 mdashPPCM40 56 222 12 3420 141410 597PSC M40 39 458 14 3200 24650 930


28 days90 days

PPC PSCOPCTypes of cement

0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)

Figure 4 Comparison of compressive strength of M30 grade OPCPPC and PSC concrete types

in the magnitude of current flow in bothM30 andM40 gradeconcrete types The percentage reduction in the current flowwas 4189 and 5666 for PSC system at 28 and 90 daysof curing period These data confirmed the impermeabilitynature of blended cement concrete types

331 Time Taken for Initial Crack The time taken for initialcrack measured for 28- and 90-day cured OPC PPC andPSC concrete types was given in Table 4The results indicatedthat both 28- and 90-day curedM30 andM40 grade concretetypes showed the following order with respect to time takenfor initial crack

OPC lt PPC lt PSC (7)

28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)


Among the three concrete types PSC concrete in M30and M40 grades 28- as well as 90-day cured specimensshowed the longest time taken for initial crack For examplefor 28-day curedM30 andM40 concrete time taken for initialcrack observed was at 10 and 14 days respectively Similartrend was observed for 90-day cured concrete

The better performance of PSC is due to the following rea-son Aluminate phase is the most responsible one for bindingthe chlorides into complex forms Fixing of chloride in con-crete by the formation of complex aluminate phases has beenreported byKarthick et al [37] About 50 to 80 of chlorideions are bound by aluminate phases by the action of calcium


M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)

Figure 6 Comparison of corrosion rate of rebar in OPC PPC andPSC concrete types obtained by impressed voltage test (28-day curedspecimens)

M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)


oxide and aluminate with chloride forming calcium chloroa-luminate complexes (CaOsdotAl

2O3sdotNaCl

2sdot10H2O) With the

result the time taken for initial crack was increasedThe free chloride contents showed the lower values for

PSC concrete This can be attributed to the formation of freechlorides into complex form The mechanism of the forma-tion of complex namely Friedel salt is by the precipitationmethod

332 Corrosion Rate of Embedded Steel The corrosion ratesof embedded steel in OPC PPC and PSC were given inFigures 6 and 7 respectively

The corrosion rates of steel calculated for 28 days curedM30 OPC PPC and PSC concrete types were found tobe 00150 00075 and 00060mmpy respectively Theseresults showed that blended cements namely PPC and PSCconsiderably decreased the corrosion rate of embedded steelby 2 times and 25 times Similar trend was also observed in

M40 grade concrete PPC and PSC concrete types showed 17times and 3 times reduction in corrosion rate when comparedto OPC concrete

The corrosion rate values calculated for 90 days curedM30 OPC PPC and PSC concrete types were found to be00110 00060 and 00035mmpy respectively These resultsshowed that blended cements namely PPC and PSC consid-erably decreased the corrosion rate of embedded steel by 2and 3 times respectively A similar trend was also observedin M40 grade concrete PPC and PSC concrete types showed22 and 33 times reduction in corrosion rate when comparedto OPC concrete

For reinforcement corrosion to occur a critical quantityof chloride is required at the steelconcrete interface In OPCthe critical chloride is reached in a very short time whereas ittookmore time for PPC and PSC concrete types as evidencedby the time taken for initial crackThe considerable reductionin corrosion rate of the blended cements was attributed tothe secondary pozzolanic reaction in blended cements whichfavoured more C-S-H gel formation and interconnectedthe micropores present in the blended cements Moreoverthe PSC showed the least corrosion rate values because inaddition to the secondary pozzolanic reaction the higherAl2O3content adsorbed more free chloride and formed

chloroaluminate complex [37] Thus the free chloridesmainly responsible for inducing the reinforcement corrosionwere considerably reduced and hence a marked reduction incorrosion rate values was observed

Better corrosion resistant properties were observed forPSC concrete that exhibited the minimum current flowlowest free chloride contents and lower corrosion rate

34 Rapid Chloride Permeability Test The amount of chargethat passed (coulombs) throughOPC PPC andPSC concretetypes cured after 28 and 90 days was reported in Table 5In M30 grade 28-day cured concrete showed 669 281 and226 coulombs for OPC PPC and PSC concrete typesrespectively The results obtained for M40 grade concreteshowed 626 261 and 204 coulombs for OPC PPC andPSC concrete types respectively This showed that in M40grade concrete due to the higher cement content the higherreactivity of Ca(OH)

2with SiO

2leads to the formation of C-

S-H gel which reduced the micro- and macropores presentin the concrete Besides PSC and PPC cement consists ofhigher amount of Al

2O3(100 to 105) when compared to

OPC (55) which interacted with Ca(OH)2and favoured

formation of calcium chloroaluminate complexes (chloridebinding effect) which made the concrete more impermeable[38] For this reason the amount of charge that passedreduced considerably inM40 grade concrete when comparedto M30 grade concreteThe results indicated that the amountof charge that passed considerably reduced in the case ofboth M30 and M40 grade PPC (238 and 239 times) andPSC (296 and 306 times) concrete types when compared toOPCconcreteThe refinement of the pore structure occurringin blended cements considerably reduced the permeation ofaggressive chloride ions The same trend was observed bySaraswathy and Song by replacing 15 with 30 RHA [30]


Table 5 Rapid chloride permeability test (RCPT) parameters for OPC PPC and PSC M30 and M40 grade concrete types

Grade

28 days 90 days

Charge passed (coulomb)Free chloridecontents(ppm)

Chloridediffusioncoefficient

(cm2sminus1) times 10minus10

Chargepassed

(coulombs)



(cm2sminus1) times 10minus10OPCM30 669 749 24 630 579 19PPC M30 281 681 18 220 528 15PSC M30 226 481 10 200 380 14OPC M40 626 540 18 600 520 14PPC M40 261 532 15 180 483 08PSC M40 204 596 05 200 393 06

341 Chloride Diffusion Coefficient The chloride diffusioncoefficient (CDC) calculated for 28- and 90-day cured OPCPPC and PSC concrete types was reported in Table 5 Theresults indicated that both 28- and 90-day cured M30 andM40 grade concrete types showed the decreasing trend asfollows

OPC gt PPC gt PSC (8)

In PSC M30 and M40 grade 28- as well as 90-daycured concrete showed the least chloride diffusion coefficient(CDC) values For example in M30 grade 28-day curedconcrete the CDC values are found to be 18 times 10minus10 cm2sminus1and 10 times 10minus10 cm2sminus1 for PPC and PSC concrete typesrespectively In M40 grade 90-day cured concrete CDCvalues are 08 times 10minus10 cm2sminus1 and 06 times 10minus10 cm2sminus1 for PPCand PSC concrete types respectively For high performanceconcrete the CDC values were found to be of the order of10ndash12 cm2 sminus1The considerable lowerCDCvalues for blended

cements were attributed to their impermeability nature that isdue to the refinement of their pore structure [39]

35 Potentiodynamic Polarization Technique Potentiody-namic polarization curves obtained for the corrosion of rebarin various types of cement concrete were shown in Figure 8The corrosion kinetic parameters for rebar embedded inOPC PPC and PSC for M30 and M40 grade and 90-daycured concrete specimens were given in Table 6

The corrosion potential of rebar in M30 concrete typesfrom OPC PPC and PSC are minus397 minus303 and minus299mVrespectively PSC concrete improves the corrosion resistanceof rebar when compared to OPC concrete There is a differ-ence of minus97mV which moves in the positive direction forPSC cement concrete The corrosion rates of rebar types inOPC PPC and PSC are 69922 times 10minus3 16902 times 10minus3 and14448 times 10minus3mmpy respectively The corrosion rate of PPCand PSC was reduced 4088 and 478 times when comparedtoOPCThe corrosion current density for rebar in three typesof cement concrete at the end of exposure is as follows

14449 times 10minus4mA sdot cmminus2PSC

lt 16902 times 10minus4mA sdot cmminus2PPC

lt 69922 times 10minus4mA sdot cmminus2OPC (9)

In M40 grade concrete the measured corrosion potentialwas minus301 minus263 and minus258mV versus SCE for OPC PPC andPSC respectivelyThe variation in potential forM40 PPC and

PSC concrete types when compared to OPC was found to beless than M30 grade concrete The corrosion current densityfor M40 concrete follows the same order as M30 concrete




The PSC and PPC concrete types exhibit lower corrosioncurrent density and lowest corrosion rate when compared totheir OPC concrete counterpart

36 AC-Impedance Measurements Impedance diagramsobtained for the frequency range 001Hz to 30 kHz at theOCP for the corrosion of rebar in different concrete types


OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE

10minus5 10minus4 10minus3 10minus210minus6

log i (mAmiddotcmminus2)

(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE

10minus5 10minus4 10minus310minus6


(b)

Figure 8 Potentiodynamic polarization curves for TMT rebar embedded in OPC PPC and PSCM30 (a) and M40 (b) grade concrete types(90-day cured specimens)

Table 6 Potentiodynamic polarization parameters for the corrosion of rebar embedded in OPC PPC and PSCM40 grade concrete (90-daycured specimens)

System

Various grades of concreteM30 M40

119864corr(mV versus

SCE)

119868corr(mAsdotcmminus2) times 10minus4

Corrosion rate(mmpy) times 10minus3


SCE)



OPC minus397 69922 80082 minus301 21496 2491PPC minus303 16902 19589 minus263 16902 19589PSC minus299 14448 1674 minus258 14448 1674

were shown in Figure 9 The corrosion parameters for rebartypes in OPC PPC and PSC of M30 and M40 grade 90-daycured concrete types are given in Table 7 It is seen from thefigure that the impedance diagram is not a perfect semicircleThis difference has been attributed to frequency dispersion

From the table it is found that 119877ct (charge transferresistance) values were found to be higher for both PPC andPSC when compared to OPC in both M30 and M40 gradeconcrete types which indicates that PPC and PSC have bettercorrosion resistance than OPC The corrosion rate values inM30 grade PPC and PSC concrete types were observed to

be 112 and 127 times less when compared with OPC InM40 grade concrete 119877ct values observed for OPC PPC andPSC were 1399 times 106 1594 times 106 and 1714 times 106 ohmsdotcm2respectively This indicated that M40 grade concrete has twoorders of magnitude higher corrosion resistance than M30grade concrete

Nyquist plots clearly indicated that rebar types embeddedin PSC and PPC concrete performed better than OPC Thecorrosion rates of rebar in various concrete types at the endof 24monthsrsquo exposure inM30 andM40 grade concrete typesare as follows

8728 times 10minus3mmpyM30 PSC

lt 7782 times 10minus3mmpyPPC

lt 6873 times 10minus3mmpyOPC




(11)


Table 7 AC-impedance parameters for the corrosion of rebar embedded in OPC PPC and PSC M40 grade concrete (90-day curedspecimens)

System


119877ct(ohmssdotcm2) times 104

119868corr(mAcm2) times 10minus4





OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764

From the results it is observed that PSC concrete showedthe higher charge transfer resistance and lowest corrosion ratewhen compared to PPC and OPC concrete types

37 Macrocell Corrosion Studies The half-cell potential ofsteel measured periodically against SCE with time for OPCPPC and PSC forM30 andM40 grade 90-day cured concretetypes was shown in Figures 10 and 11 It was observedfrom Figure 10 that steel embedded in M30 grade OPCPPC and PSC concrete types is showing active conditionwithin 3 4 and 5 cycles of exposure respectively After 5cycles all the three types of concrete types were showing thepotential more negative than minus275mV versus SCE indicatingthe active condition of the rebar due to the ingress of chlorideions whereas in M40 grade concrete the OPC PPC andPSC reached the active condition at 7 9 and 11 cycles ofexposure respectively In M30 grade concrete the potentialgets stabilized after 12 cycles of exposure for all the types ofconcrete types and it reached a maximum active potentialof minus610mV minus530mV and minus501mV for OPC PPC and PSCrespectively at the end of 24 cycles In M40 grade concreteafter 11 cycles of exposure both PPC and PSC have showngradual increase in potential to the active state reaching apotential of minus420mV and minus400mV at the end of 24th cycleBut OPC has shown a more negative potential of minus520mVat the end of 24th cycle These results indicated that the PSCconcrete performed better than PPC andOPC concrete types

The macrocell current measured periodically with timeforM30 andM40 gradeOPC PPC and PSC concrete types isshown in Figures 12 and 13 From Figure 12 it is observed thatM30 OPC concrete that crossed the critical current of 10 120583Ashowed the highermagnitude ofmacrocell current flow at theend of 24 cycles of exposure indicating the severe corrosionof the embedded steelThemacrocell currentmeasured at theend of the 24th cycle was 72 120583A 60120583A and 54120583A for OPCPPC and PSC concrete types respectively

From Figure 13 it is observed that in M40 grade concreteOPC reached the thresholdmacrocell current of 10 120583Awithin2 cycles of exposure and PPC and PSC reached the microcellcurrent at 4th and 6th cycles of exposure The macrocellcurrent measured at the end of 24th cycle was 60 120583A 45 120583Aand 34 120583A for OPC PPC and PSC respectively

The total integrated current calculated (ASTMG109)withtime for M30 grade OPC PPC and PSC concrete types isillustrated in Figure 14 From the figure it was observed

that at the end of the exposure (24th cycle) OPC concreteshowed the higher value of 1200 coulombs whereas PPC andPSC exhibited 800 and 500 coulombs respectively Figure 15shows the total integrated current versus number of cyclesfor M40 grade OPC PPC and PSC concrete types From thefigure it is observed that the coulomb values observed forOPC PPC and PSC were 900 700 and 600 respectively Inboth M30 and M40 grades of concrete PPC and PSC showeda coulomb value of less than 1000 indicating the blendedcements have very low chloride penetration ButOPC showed1200 coulombs inM30 grade and 900 coulombs inM40 gradeconcrete types InM30 grade concrete OPC is graded as a lowpermeable concrete But in both the grades of concrete PPCand PSC were graded as a very low permeable concrete as perASTM C1202-12 [32]

In the case of OPC system the availability of chloride ionsthat occupied the defect position and reacted with ferrousions initiated the corrosion process But in the case of PPCand PSC concrete types the availability of free chloride issignificantly reduced due to the formation of chloroaluminatecomplexes [37] As a result there is a considerable reductionin the magnitude of current flow which was observed in PPCand PSC concrete types

4 Conclusions

The following conclusions were drawn from the above inves-tigation

(i) Mechanical properties are not altered by usingblended cements but corrosion resistant propertiesare greatly improved

(ii) The effective porosity and coefficient of water absorp-tion values showed the decreasing order as followsOPCgtPPCgtPSCAmong the three types of concreteused PSC concrete showed the least pores and lowercoefficient of water absorption

(iii) Better corrosion resistant properties were observedfor PSC concrete types by showing a minimumcurrent flow lowest free chloride contents and lessercorrosion rate and thereby the time taken for ini-tiation of crack period was extended in acceleratedimpressed voltage technique


OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)

Figure 9Nyquist plots for TMT rebar embedded inOPC PPC andPSCM30 (a) andM40 (b) grade concrete types (90-day cured specimens)

OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE

5 10 15 20 250Number of cycles

Figure 10 Potential versus number of cycles of exposure for rebar inOPC PPC and PSCM30 grade concrete types (90-day cured specimens)under macrocell condition

OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)


Figure 12 Macrocell current versus number of cycles of exposurefor rebar in OPC PPC and PSC M30 grade concrete types (90-daycured specimens) under macrocell condition

OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)


Figure 13 Macrocell current versus number of cycles of exposurefor rebar in OPC PPC and PSC M40 grade concrete types (90 dayscured specimens) under macrocell condition

(iv) In the case of M30 grade concrete cured for 28 daysthe corrosion rate was considerably decreased by 2and 25 times for PPC and PSC respectively

(v) In the case of M40 grade concrete cured for 28 daysPPC and PSC concrete types showed 17 and 3 timesreduction in corrosion rate when compared to theOPC concrete

(vi) RCPT indicated that both 28- and 90-day cured M30andM40 grade concrete types showed the decrease inCDC values as follows OPC gt PPC gt PSC

OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)


Figure 14 Total integrated current versus number of cycles ofexposure for rebar in OPC PPC and PSCM30 grade concrete types(90-day cured specimens) under macrocell condition

OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



(vii) Macrocell corrosion studies revealed that PPC andPSC concrete types are graded as very low chloridepermeability concrete in both M30 and M40 gradeconcrete types

(viii) Electrochemical studies also proved beyond doubtthat PSC concrete performed better than PPC andOPC concrete types

Conflicts of Interest

The authors declare that there are no conflicts of interestregarding the publication of this paper


Acknowledgments

This research was supported by the Basic Science ResearchProgram through theNational Research Foundation of Korea(NRF) funded by the Ministry of Science ICT amp FuturePlanning (no 2015R1A5A1037548)

References

[1] EGuneyisi T Ozturan andMGesoglu ldquoEffect of initial curingon chloride ingress and corrosion resistance characteristics ofconcretes made with plain and blended cementsrdquo Building andEnvironment vol 42 no 7 pp 2676ndash2685 2007

[2] V Saraswathy and H-W Song ldquoImproving the durability ofconcrete by using inhibitorsrdquoBuilding and Environment vol 42no 1 pp 464ndash472 2007

[3] H-W Song and V Saraswathy ldquoCorrosion monitoring ofreinforced concrete structures a reviewrdquo International Journalof Electrochemical Science vol 2 no 1 pp 1ndash28 2007

[4] T H Wee A K Suryavanshi and S S Tin ldquoEvaluation ofrapid chloride permeability test (RCPT) results for concretecontaining mineral admixturesrdquo ACI Structural Journal vol 97no 2 pp 221ndash232 2000

[5] G Chirag and J Aakash ldquoGreen concrete efficient and eco-friendly construction materialsrdquo in Proceedings of the nterna-tional Journal of Research in Engineering and Technology vol 2pp 259ndash264 2014

[6] V M Malhotra Role of supplementary cementing materials inreducing greenhouse gas emissions Report MTL 98-03 (OPamp)Natural resource Ottawa Ottawa Canada 1998

[7] E Guneyisi T Ozturan and M Gesoglu ldquoLaboratory investi-gation of chloride permeability for high performance concretecontaining fly ash and silica fumerdquo R K Dhir Ed pp 295ndash305Dundee Scotland 2002

[8] V Saraswathy S Muralidharan R M Kalyanasundaram KThangavel and S Srinivasan ldquoEvaluation of a compositecorrosion-inhibiting admixture and its performance in concreteunder macrocell corrosion conditionsrdquo Cement and ConcreteResearch vol 31 no 5 pp 789ndash794 2001

[9] V Saraswathy SMuralidharan KThangavel and S SrinivasanldquoActivated fly ash cements Tolerable limit of replacementfor durable steel reinforced concreterdquo Advances in CementResearch vol 14 no 1 pp 9ndash16 2002

[10] V Saraswathy SMuralidharan KThangavel and S SrinivasanldquoInfluence of activated fly ash on corrosion-resistance andstrength of concreterdquo Cement and Concrete Composites vol 25no 7 pp 673ndash680 2003

[11] V Saraswathy SMuralidharan KThangavel and S SrinivasanldquoElectrochemical studies on the corrosion performance ofactivated fly ash blended cementsrdquo Materials Engineering vol14 pp 261ndash283 2003

[12] S Muralidharan V Saraswathy S P M Nima and NPalaniswamy ldquoEvaluation of a composite corrosion inhibitingadmixtures and its performance in Portland pozzolana cementrdquoMaterials Chemistry and Physics vol 86 no 2-3 pp 298ndash3062004

[13] G A Habeeb and H B Mahmud ldquoStudy on properties of ricehusk ash and its use as cement replacement materialrdquoMaterialsResearch vol 13 no 2 pp 185ndash190 2010

[14] F Sajedi andH A Razak ldquoEffects of curing regimes and cementfineness on the compressive strength of ordinary Portland

cement mortarsrdquo Construction and Building Materials vol 25no 4 pp 2036ndash2045 2011

[15] ACI 308-92 Standard Practice for curing concrete (ACI 308-92)ACI Committee American Concrete Institute Farmington HillsMich USA 1998

[16] P S Mangat and M C Limbachiya ldquoEffect of initial curingon chloride diffusion in concrete repair materialsrdquo Cement andConcrete Research vol 29 no 9 pp 1475ndash1485 1999

[17] V Bonavetti H Donza V Rahhal and E Irassar ldquoInfluence ofinitial curing on the properties of concrete containing limestoneblended cementrdquo Cement and Concrete Research vol 30 no 5pp 703ndash708 2000

[18] J M Khatib and P S Mangat ldquoInfluence of high-temperatureand low-humidity curing on chloride penetration in blendedcement concreterdquo Cement and Concrete Research vol 32 no 11pp 1743ndash1753 2002

[19] N Shafiq and J G Cabrera ldquoEffects of initial curing conditionon the fluid transport properties in OPC and fly ash blendedcement concreterdquo Cement and Concrete Composites vol 26 no4 pp 381ndash387 2004

[20] G Erhan O Juran and G Mehmet ldquoA study of reinforcementcorrosion and related properties of plain and blended cementconcrete under different curing conditionsrdquo Cement and Con-crete Composites vol 27 pp 449ndash461 2005

[21] S K Antiohos V G Papadakis E Chaniotakis and S TsimasldquoImproving the performance of ternary blended cements bymixing different types of fly ashesrdquo Cement and ConcreteResearch vol 37 no 6 pp 877ndash885 2007

[22] T R Naik S S Singh and M M Hossain ldquoEnhancement inmechanical properties of concrete due to blended ashrdquo Cementand Concrete Research vol 26 no 1 pp 49ndash54 1996

[23] T-C Lee W-J Wang P-Y Shih and K-L Lin ldquoEnhancementin early strengths of slag-cementmortars by adjusting basicity ofthe slag prepared from fly-ash of MSWIrdquo Cement and ConcreteResearch vol 39 no 8 pp 651ndash658 2009

[24] T Nochaiya W Wongkeo and A Chaipanich ldquoUtilization offly ash with silica fume and properties of Portland cement-flyash-silica fume concreterdquo Fuel vol 89 no 3 pp 768ndash774 2010

[25] Specification for 43 grade Ordinary Portland Cement IS 8112BIS Standards New Delhi India 2013

[26] Specification for Portland Pozzolana Cement (fly ash based) IS1489 BIS Standards New Delhi India 1991

[27] Specification for Portland slag cement IS 455 BIS StandardsNew Delhi India 2015

[28] Specification for high strength deformed steel bars and wiresfor concrete reinforcement IS 1786 BIS Standard New DelhiIndia 2008

[29] ASTM C642 ndash 97 ldquoStandard Test Method for Density Absorp-tion and Voids in Hardened Concreterdquo in Proceedings of theASTM International West Conshohocken PA USA 1997

[30] V Saraswathy and H-W Song ldquoCorrosion performance ofrice husk ash blended concreterdquo Construction and BuildingMaterials vol 21 no 8 pp 1779ndash1784 2007

[31] ASTM G1-03 ldquoStandard practice for preparing cleaning andevaluating corrosion test specimensrdquo in Proceedings of theASTM International West Conshohocken PA USA 2011

[32] ASTMC1202-12 ldquoStandard testmethod for electrical indicationof concretes ability to resist chloride ion penetrationrdquo inProceedings of the ASTM International West ConshohockenPA USA 2012


[33] H-W Song V Saraswathy S Muralidharan C-H Lee andK Thangavel ldquoCorrosion performance of steel in compositeconcrete system admixed with chloride and various alkalinenitritesrdquo Corrosion Engineering Science and Technology vol 44no 6 pp 408ndash415 2009

[34] ASTMG109-07 ldquoStandardTestMethod forDetermining Effectsof Chemical Admixtures onCorrosion of Embedded Steel Rein-forcement in Concrete Exposed to Chloride Environmentsrdquo inProceedings of the ASTM International West ConshohockenPA USA 2013

[35] V Saraswathy S Muralidharan L Balamurugan P KathirvelandA S S Sekar ldquoEvaluation of composite cements using cyclicpolarization techniquesrdquoKSCE Journal of Civil Engineering vol15 no 8 pp 1415ndash1418 2011

[36] M S Meddah and A Tagnit-Hamou ldquoPore structure of con-crete with mineral admixtures and its effect on self-desiccationshrinkagerdquo ACI Materials Journal vol 106 no 3 pp 241ndash2502009

[37] S P Karthick S Muralidharan V Saraswathy and S KwonldquoEffect of different alkali salt additions on concrete durabilitypropertyrdquo Journal of Structural Integrity and Maintenance vol1 no 1 pp 35ndash42 2016

[38] K Thangavel S Muralidharan V Saraswathy K Y Ann andL Balamurugan ldquoRelationship between alumina and chloridecontent on their physical and corrosion resistance properties ofconcreterdquo Arabian Journal for Science and Engineering vol 35no 2 A pp 27ndash38 2010

[39] E Berodier and K Scrivener ldquoEvolution of pore structure inblended systemsrdquo Cement and Concrete Research vol 73 pp25ndash35 2015

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of



strength characteristics are fineness modulus water-cementratio (wc) chemical composition and so on [14 15] Manyresearchers have discussed the different types of curingpore structure refinement and permeability characteristics ofblended cements by using fly ash slag silica fume and soon [16ndash19] The results indicated that blended cement withlonger duration has shown strength and other propertiesequal to those of ordinary Portland cement It is also reportedthat blended cements enhanced the workability durabilityandmechanical properties of the concrete [20ndash24] So far thestudies have focused on the particular aspect of corrosion likepermeability pore structure chloride ingress or physical andchemical characteristics by either short-term or long-termstudies

Hence the aim of the present investigation is to evaluatethe corrosion resistant properties of rich and lean mixconcrete made from Portland pozzolana cement (PPC) andPortland slag cement (PSC) under accelerated and nor-mal exposure conditions The results were compared withordinary Portland cement (OPC) concrete Further in thisinvestigation two curing periods two grades of concreteand two different exposure conditions namely normal andaccelerated exposure conditions were carried out In additionto these short-term and long-term tests porosity and perme-ability studies and mechanical and electrochemical studieswere also carried out for plain and blended cements and theresults were presented in a detailed manner

2 Experimental

21 Materials and Mix Proportions Two mix proportionshaving characteristic compressive strength of 30 and 40MPa concrete types were used for casting the concretespecimens The details of concrete mix proportions are givenin Table 1Three cements namely 43 grade ordinary Portlandcement conforming to IS8112 [25] (equivalent to ASTM-Type I cement) Portland pozzolana cement conforming toIS1489ndashPart-I [26] and Portland slag cement conformingto IS455 [27] were used Chemical composition of cementsused is given in Table 2 Graded river sand passing through118mm sieve with a fineness modulus of 285 and a specificgravity of 255 was used as fine aggregate Locally availablewell graded aggregates of normal size greater than 475mmand less than 20 mm having a fineness modulus of 272were used as coarse aggregates The specific gravity of thefine aggregate used was 278 Thermomechanically treated(TMT) rebar (Fe-415 grade) of 12mm diameter conformingto IS1786 [28] was used Potable water was used for castingthe concrete

22 Methods

221 Compressive Strength Compressive strength test wascarried out in concrete cubes of size 150 times 150 times 150mmusing 1 18 369 mix with wc ratio of 055 (M30 grade) and1 118 336 with wc ratio 045 (M40 grade) using OPC andblended cements (PPC and PSC) During casting themouldswere mechanically vibrated After 24 hours the specimens

Concretespecimen

Sides sealedwith epoxy resin

Shallow pan of water

100 mm

5mm

100

mm

Figure 1 Schematic of coefficient of water absorption test

were removed from the mould and subjected to water curingfor 28 and 90 days After a specified period of curing thespecimens were tested for compressive strength using AIMILcompression testing machine of 2000 kN capacity at a rateof loading of 210 kNmin The tests were carried out on sixspecimens and the average compressive strength values wererecorded for OPC PPC and PSC concrete types

222 Effective Porosity Test Percentage of water absorptionis a measure of the pore volume or porosity in hardenedconcrete which is occupied by water in saturated conditionWater absorption test was carried out as per ASTM C642-97[29] The effective porosity for OPC PPC and PSC concretetypes is calculated as follows

Effective porosity () = (119861 minus 119860)119881 times 100 (1)

where 119860 is mass of oven dried sample in air 119861 is saturatedmass of the surface dry sample in air after immersion and 119881is bulk volume of the sample

223 Coefficient of Water Absorption Coefficient of waterabsorption is suggested as ameasure of permeability of waterThis ismeasured by the rate of uptake ofwater by dry concreteover a period of 1 h The concrete cube specimens of 100 times100 times 100mm were preconditioned by drying in an oven at105∘C for 48 hrs until constant weight was reached and thenallowed to cool in an airtight sealed container for 3 days Thesides of the concrete samples were coated with transparentepoxy resin to allow the flow of water in unidirectionThen the samples were kept in a vertical position partiallyimmersed up to a depth of 5mm at one end while the restof the portions were kept exposed to the atmosphere asshown in Figure 1 The quantity of water absorbed during thefirst 60min was calculated Coefficients of water absorptionvalues for OPC PPC and PSC concrete specimens after 28and 90 days of moisture curing were determined using theformula [29]

119870119886= (119876119860)

2

times 1119905 (2)

where 119870119886is the coefficient of water absorption (m2sminus1) 119876 is

the quantity of water absorbed (m3) by the oven dry specimen






Water(kgmminus3)

M30OPC 055 338 607 1247 186PPC 055 338 607 1247 186PSC 055 338 607 1247 186

M40OPC 045 400 472 1247 180PPC 045 400 472 1247 180PSC 045 400 472 1247 180



SiO2

210 320 310Al2O3

550 100 105Fe2O3

460 550 280CaO 630 440 470MgO 060 150 390SO3

260 260 260LOI 270 440 270








119863 = 1198691198771198791198711198851198651198620119864 (4)





rebar

Connection wire

Concrete

100 mm

12 mm dia


100mm



119888) and anodic















V

3 NaCl

Sealed withepoxy

PVC sheet

114 mm



75mm

75mm

25 mm

20 mm

114 mm

152mm107 mm

279mm

25 mm

20 mm

152

mm





M30OPC 1515 1072 320 230PPC 1428 962 250 200PSC 1261 957 071 040

M40OPC 1328 943 300 190PPC 1242 679 290 110PSC 1061 632 062 015



2O


(5)







2O3



3A and






(mA)

()reduction



Weight loss(mg)




28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)


M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)



2O3sdotNaCl












2with SiO








Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of







Water(kgmminus3)

M30OPC 055 338 607 1247 186PPC 055 338 607 1247 186PSC 055 338 607 1247 186

M40OPC 045 400 472 1247 180PPC 045 400 472 1247 180PSC 045 400 472 1247 180



SiO2

210 320 310Al2O3

550 100 105Fe2O3

460 550 280CaO 630 440 470MgO 060 150 390SO3

260 260 260LOI 270 440 270








119863 = 1198691198771198791198711198851198651198620119864 (4)





rebar

Connection wire

Concrete

100 mm

12 mm dia


100mm



119888) and anodic















V

3 NaCl

Sealed withepoxy

PVC sheet

114 mm



75mm

75mm

25 mm

20 mm

114 mm

152mm107 mm

279mm

25 mm

20 mm

152

mm





M30OPC 1515 1072 320 230PPC 1428 962 250 200PSC 1261 957 071 040

M40OPC 1328 943 300 190PPC 1242 679 290 110PSC 1061 632 062 015



2O


(5)







2O3



3A and






(mA)

()reduction



Weight loss(mg)




28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)


M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)



2O3sdotNaCl












2with SiO








Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



rebar

Connection wire

Concrete

100 mm

12 mm dia


100mm



119888) and anodic















V

3 NaCl

Sealed withepoxy

PVC sheet

114 mm



75mm

75mm

25 mm

20 mm

114 mm

152mm107 mm

279mm

25 mm

20 mm

152

mm





M30OPC 1515 1072 320 230PPC 1428 962 250 200PSC 1261 957 071 040

M40OPC 1328 943 300 190PPC 1242 679 290 110PSC 1061 632 062 015



2O


(5)







2O3



3A and






(mA)

()reduction



Weight loss(mg)




28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)


M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)



2O3sdotNaCl












2with SiO








Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



V

3 NaCl

Sealed withepoxy

PVC sheet

114 mm



75mm

75mm

25 mm

20 mm

114 mm

152mm107 mm

279mm

25 mm

20 mm

152

mm





M30OPC 1515 1072 320 230PPC 1428 962 250 200PSC 1261 957 071 040

M40OPC 1328 943 300 190PPC 1242 679 290 110PSC 1061 632 062 015



2O


(5)







2O3



3A and






(mA)

()reduction



Weight loss(mg)




28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)


M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)



2O3sdotNaCl












2with SiO








Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of






(mA)

()reduction



Weight loss(mg)




28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





28 days90 days


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)





M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)


M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)



2O3sdotNaCl












2with SiO








Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



M30M40

PPC PSCOPC

0004

0006

0008

0010

0012

0014

0016C

orro

sion

rate

(mm

py)


M30M40

PPC PSCOPC00020003000400050006000700080009001000110012

Cor

rosio

n ra

te (m

mpy

)



2O3sdotNaCl












2with SiO








Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of




Grade

28 days 90 days




Chargepassed

(coulombs)





















OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



OPCPPCPSC

minus600

minus500

minus400

minus300

minus200

minus100

Pote

ntia

l (m

V) v

ersu

s SCE



(a)

OPCPPCPSC

minus500

minus400

minus300

minus200

minus100

0

100

Pote

ntia

l (m

V) v

ersu

s SCE



(b)



System



SCE)




SCE)














(11)



System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of




System








OPC 3464 7531 8728 1399 1865 2161PPC 3885 6715 7782 1594 1637 1897PSC 4399 5930 6873 1714 1522 1764








4 Conclusions






OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



OPCPPCPSC

0

5000

10000

15000

20000

25000

30000Z

(Ω

middotcm2)

30000 600005000040000 7000020000Z (Ωmiddotcm2)

(a)

OPCPPCPSC

0

200000

400000

600000

800000

1000000

1200000

1400000

Z

(Ωmiddotcm

2)

250000 500000 750000 1000000 1250000 15000000Z (Ωmiddotcm2)

(b)


OPCPPCPSC

minus200

minus300

minus400

minus500

minus600

Pote

ntia

l mV

ver

sus S

CE



OPCPPCPSC

minus100

minus200

minus300

minus400

minus500

Pote

ntia

l mV

ver

sus S

CE




OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



OPCPPCPSC

0

10

20

30

40

50

60

70

80

Mac

roce

ll cu

rren

t (

A)



OPCPPCPSC

0

10

20

30

40

50

60

Mac

roce

ll cu

rren

t (

A)






OPCPPCPSC

0

200

400

600

800

1000

1200

Tota

l int

egra

ted

curr

ent (

coul

ombs

)



OPCPPCPSC

0

200

400

600

800

1000

Tota

l int

egra

ted

curr

ent (

coul

ombs

)








Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of

















CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Comparative Study of Strength and Corrosion Resistant...

Documents

Transcript of Comparative Study of Strength and Corrosion Resistant...