Research Article On the Fresh/Hardened Properties of...

Research ArticleOn the FreshHardened Properties ofCement Composites Incorporating Rubber Particles fromRecycled Tires

Alessandra Fiore1 Giuseppe Carlo Marano1 Cesare Marti1 and Marcello Molfetta2

1 Technical University of Bari DICAR Via Orabona 4 70125 Bari Italy2 Italcementi Group SpA Via Vivaldi 13 24125 Bergamo Italy

Correspondence should be addressed to Alessandra Fiore afiorepolibait

Received 28 March 2014 Revised 24 September 2014 Accepted 24 September 2014 Published 30 October 2014

Academic Editor Samer Madanat

Copyright copy 2014 Alessandra Fiore et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

This study investigates the ameliorative effects on some properties of cement-based materials which can be obtained byincorporating rubber particles as part of the fine aggregates The aim is to find out optimal cement compositemortar mixturescontaining recycled-tyre rubber particles suitable for specific engineering applications Different percentages of rubber particlesfrom 0 to 75 were used and for each percentage the suitable amount of sand was investigated in order to achieve the bestfreshhardened performances In particular the following characteristics were examined density compressive strength modulusof elasticity shrinkage weight loss flexural behaviour thermal conductivity rapid freezing and thawing durability and chloridepermeability The experimental results were compared with the ones of cement composite specimens without rubber aggregatesTest results show that the proposed rubberized mortar mixes are particularly suitable for some industrial and architecturalapplications such as under-rail bearings road constructions paving slabs false facades and stone backing

1 Introduction

The growing amount of waste rubber produced from tireshas been a major concern in the last decades because tiresrepresent a huge no-biodegradable refusal with danger offires and proliferation of rats and insects in the stockedrefuse mass The need to explore recycling strategies is soimperious A variety of waste materials have been suggestedas additives to cement-based materials due to the need toease the intake of resources for the production of concrete andto improve some performances of concrete with economicand technological advantages

During the last two decades several internationalresearches have been focused on the properties and perfor-mances of rubberized cement matrix composites [1ndash9] Therubber obtained from the recycling of waste tyres in fact is apromising material with some interesting applications in theconstruction industry for its lightness elasticity absorption

capacity of energy and acoustic and thermal insulationRubber derives from postconsumption tires subjected tomechanical trituration or to cryogenic processes the textilecomponents are sometimes removed and the steel fibersunstrained The rubber surface is usually subjected to chem-ical pretreatments to obtain an improvement of some finalproperties of concrete

It is very important to specify the rubber source becauseit influences the characteristics of concretemortar for theconstituent materials proportion of the components shapeweight and size Tires used for rubberized cement com-posites derive from car or truck tires The first ones aremore used and are characterized by a greater quantity ofrubberelastomers (48 while trucks contain 43) theycontain 5 of textile component while truck tires do notcontain it the percentage of steel fibres is 15 in motorvehicle tires while 27 in truck tires Rubber can be dividedinto three categories chipped rubber (dimensions of about

Hindawi Publishing CorporationAdvances in Civil EngineeringVolume 2014 Article ID 876158 12 pageshttpdxdoiorg1011552014876158

2 Advances in Civil Engineering

25ndash30mm) used to replace the coarse aggregates crumbrubber (3ndash10mm) used to replace sand ash rubber (smallerthan 1mm) used as a filler

Crumbed rubber (CR) from vehicle tyres mixed inwith cement composites induces serious variations in thematerial properties The results of many studies demonstratethat the partial or total replacement of aggregates withrubber negatively affects mechanical properties of cement-based materials [10ndash12] proportionally to the quantity ofrubber scraps Also the size of rubber scraps affects strengthcoarse scraps reduce compressive strength more than finescraps [12ndash17] Eldin and Senouci [12] determined that whencoarse aggregate was replaced in full with mechanicallycrumbled waste rubber the compressive strength droppedby 85 whereas splitting tensile strength went down by50 However when fine aggregate was replaced in fullwith waste rubber the authors observed lower reductionin compressive strength (65) and the same reduction insplitting tensile strength (50) Studies conducted by theauthors Topcu and Avcular [18] Lee et al [19] and Parantet al [20] showed greater reduction in compressive strengthwhen coarse aggregate was replaced with CR compared to thereplacement of fine aggregate

Segre and Joekes [10] analysed the change in compressiveand bending strength of cement composites with CR added at10 of the total aggregate content To obtain a better adhesionof cement matrix and rubber the authors soaked rubberparticles in NaOH solution Scanning Electron Microscopytesting has shown that rubber particles which were soakedin NaOH solution were much more covered with cementhydrates and there were more newly formed hydrationproducts on the surface of soaked rubber particles comparedto the particles that were not soaked in NaOH solution Nev-ertheless the compressive strength of cement-basedmaterialwhere 10 of the total aggregate content was rubber particlesnot soaked in NaOH reduced by 33 compared to controlspecimens the same reduction was observed in cementmaterial with rubber particles soaked in NaOH solutionThehighest bending strength was observed in mixtures wherewaste rubber not soaked in NaOH solution was used Thebending strength of such mixes compared to control speci-mens and to cement composite containing rubber soaked inNaOH solution was higher by 94 and 10 respectivelyThereduction in compressive strength and increase in bendingstrength in cement-based materials with rubber wasteadditives were also detected by Chinese researchers [21ndash23]whereas tests of other authors [11 24ndash26] demonstratedthat both bending strength and compressive strength inconcrete with CR were lower compared to concretes withoutCR

Many authors analysed the effect of CR on concretersquossplitting tensile strength [2 11 17 27 28] Comprehensiveanalysis of literature has revealed that tensile strength reduceswith the addition of CR

The decrease in strength can be thus explained by the lackof bonding and the low adhesion between the rubber crumband the cement matrix [5 10 27] The reduction in concretestrength can also be ascribed to the circumstance that rubberparticles have lower strength than concrete matrix around

them and thus when force is applied the cracks first of allappear in the contact zone of rubber and concrete matrix[8 12 18 19] Cracks gradually propagate under load untilconcrete crumbles Such rubber performance discrepancymakes rubber particles similar to voids in cement composites[12 25 29]

In addition not only strength but also workabilitydecreases with the increasing of the percentage of rubber dueto the increasing viscosity of the mixture [4 12]

On the other hand there are several other properties ofconcrete that benefit by the presence of crumb rubber Onesignificant benefit is the property that rubber reduces massdensity [15 30] and increases deformability and ductilityso it is useful in elements that do not require an elevatedstrength but require instead the reduction of vibrations orthe increasing of resilience durability and deformability [31]and absorption of low-frequency noise [32]

Hernandez-Olivares et al [11] investigated the Youngdynamicmodulus of rubber-filled concretewith different vol-umetric fraction at low frequencies and the dissipated energyin viscoelastic regime and under compressive dynamic loadthey dealt only with specimens with low volumetric fractionof tire rubber

Zheng et al [33] tested simply supported beams withdifferent volumetric fraction of tire rubber to underline therelationships between damping ratio in small deformationand the size and amount of rubber scraps they also testedthe dynamic modulus of rubberized concrete making acomparison with the static modulus It was observed that thedamping ratio of rubberized concrete improved while thedynamic modulus elasticity of rubberized concrete resultedlower than that of plain concrete

Some authors have also discussed the time-dependentproperties of rubberized concrete which may be critical insome cases A study of van Mier et al [34] for example hasrevealed that the significant difference in Poissonrsquos ratio ofrubber particles and the cement-matrix encourages prema-ture cracking However Turatsinze et al [35] indicated thatthe higher the content of rubber shreds the smaller the cracklength and width due to shrinkage and the onset time ofcracking was more delayed

Just a few studies are available in literature on the topicof durability [36] of rubber-cement mixes They mainlyfocus on the abrasion resistance and freeze-thaw exposureperformance Sukontasukkul and Chaikaew [16] mentionedthat crumb concrete blocks show less abrasion resistanceand also that increasing the crumb rubber content leadsto a reduction in the abrasion resistance This result wasconfirmed by other authors Topcu and Demir [31] showedthat a high volume replacement of sand by rubber waste hadlower durability performance assessed by freeze-thaw expo-sure seawater immersion and high temperature cycles As tochloride permeability some results are discussed dealing withpolyethylene terephthalate bottle (PET) wastes Benosman etal [37] reported that the partial replacement of cement byPET wastes led to a reduction of the chloride ion diffusioncoefficient Bravo and de Brito performed tests for shrinkagewater absorption carbonation and chlorides penetrationresistance for concrete mixes in which just 5 10 and 15

Advances in Civil Engineering 3

of the volume of natural aggregate were replaced by aggregatederived from used tyres [38]

Although many authors do not recommend to use themodified concrete in structural elements where high strengthis required [39ndash44] rubcrete can be used in many otherconstruction elements [17] Due to its high toughness impactresistance and sound absorbtion many researchers havesuggested using rubber-concrete for jersey barriers railwaystation platforms or vibration dampers [45] However fur-ther research is needed in order to find a specific mix able tolimit the strength-loss at the aim to increase the range of usesfor rubber-concrete

In this study a number of laboratory tests were carried outon new cement-based (mortar) mixtures containing rubberparticles obtained from waste tires Different percentagesof rubber particles were used as a substitute to naturalaggregates in cement composites and for each percentage thesuitable amount of sandwas evaluated by experimental sensi-tivity tests in order to achieve the best performances Differ-ently from the existing approaches both physical-mechanicaland durability characteristics were examined such as densitycompressive strength bending strength modulus of elastic-ity shrinkage and chloride ion penetrationThis experimen-tal analysis was undertaken not only to investigate the idealrubber aggregate content for each potential use but also toconfirm the results obtained in literature in areas of doubtFurther investigations are needed on this subject especiallyto comprehend if different kinds of rubber behave in a similarmanner in terms of resistance and durability

2 Experimental Details

21 Cement-Based Mix A waste tire is composed of rub-ber black carbon steel wire and nylon fiber The maincomponents include rubber vulcanizing agent vulcanizationaccelerator accelerator antioxidant reinforcing agent fillersoftener and stain Among these rubber accounts for about70 of the whole tyre and this rubber is composed of naturaland synthetic organic compounds of petroleum

In this study crumb rubbers deriving from motor vehicletires have been tested in order to evaluate their performanceas aggregates in cement composites The used CR particlesG1-1 type were highly irregular and had a dimension of about2ndash4mm (Figure 1) They were obtained from a process ofmechanical trituration of motor vehicle tires and substitutedldquoas they wererdquo without any chemical pretreatment in differ-ent quantities to natural aggregates in the cement paste Theywere just subjected to centrifugation in order to eliminate thetrapped air

The mixes included cement Portland type II sand andwater After the realization of several trial mixtures varyingthe cement dosage the type of admixture and the quantitiesof substitute rubber particles seven rubber-cement matrixmixes were finally selected In particular seven differentquantities of substitute rubber particles were considered andfor each rubber percentage the suitable amount of sandwas investigated by experimental sensitivity tests in orderto achieve the best performances in terms of workabilitySimilarly in order to improve the compressive strength and

Figure 1 Rubber samples

reduce the percentage of air absorption for each mixturesome adjustments were made by varying the water to cementratio Also some additives such as a superfluidizer containingpolymer of polyacrylic acid and an air entraining admixturewere added These types of additives have four main benefitson cement composites encouraging strong workability withany kind of cement having a high degree of water reductionimproving the yield of the mixture lowering the content ofair Table 1 shows the quantities of the components and ofthe rubber samples used for the final selected mixtures Thesuperfluidizer and air entraining admixtures are expressed aspercentages by cement weight the air content is expressedas volume ratio In the following we will refer to a referencemixture called mix ldquoTQrdquo containing zero percentage ofrubber aggregates and to a set of mixtures called mixlaquoldquo rdquoraquo with different percentages of rubber

3 Results and Analysis

31 Fresh Properties Several tests were carried out on thefresh state at the CTG Laboratory (Italcementi Group) ofMesagne Brindisi (Italy) and they consisted of workabilityair content and mass density

For each mixture four cubic samples each 15 times 15 cmwere preparedThe workability on the fresh cement state wasmeasured with the Abramsrsquo slump test (UNI EN 11041) theair content expressed as volume ratio was tested through apressure-type air meter (UNI EN 12350-7) and the volumicmass was successively estimatedThe numerical results of thedeveloped tests are summarized in Figures 2 3 and 4 at 030 and 60 minutes The mix appeared to have a very gooddistribution of the rubber aggregates in the cement pasteand did not show any signs of segregation As can be notedfrom data collected in Figure 2 all the aforesaidmixes belongto consistency class S5 confirming a very good workabilityAs expected the density was found to decrease with anincrease of the crumb rubber content on the other hand inrubber cement composites the air content requirement wassignificantly higher than that of mix without rubber

The obtainment of lightweight cement-based material byadding rubber crumbswas partly due to the lack of aggregatesreplaced by the rubber Another cause could be the largevoids created by the rubber particles inside the cement paste


Table 1 Mixtures of cement composites

Mixtures Mix TQ Mix 10 Mix 20 Mix 30 Mix 40 Mix 50 Mix 75Sand 0 divide 4mm [kgm3] 16355 1292 1117 924 761 632 272Rubber 2 divide 4mm [kgm3] 0 70 130 182 233 289 359CEM 425 II-ALL [kgm3] 310 380 380 380 380 380 380Superfluidizer [] 04 04 04 0291 0416 04 04Air entraining admixture [] mdash 023 013 008 008 0048 003Water [kgm3] 190 195 185 180 170 160 140Air content [] 55 10 12 16 19 20 30Theoretical density [kgm3] 2137 19395 1815 1669 1545 1463 1154

000

1000

2000

3000

4000

5000

6000

7000

8000

Spre

adin

g (c

m)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Spreading 0998400

Spreading 30998400

Spreading 60998400

Figure 2 Workability of rubber cement composites

900

1400

1900

2400

(kg

m3)

Mixtures

0998400

30998400

60998400

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Figure 3 Density of rubber cement composites


35

30

25

20

15

10

5

0

Air

cont

ent (

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Figure 4 Air content of rubber cement composites

0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)

7 days28 days60 days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Figure 5 Compressive strength of rubber cement composites on days 7 28 and 60

leading to higher porosity The increase in porosity leads toan increase in air trapped in the mixture

These first results on the fresh state show that theincorporation in cement composites of rubber aggregatesobtained from waste tires can be a suitable solution in orderto decrease weight in some engineering manufactures

32 Hardened Properties On the hardened state the com-pressive and flexural strengths were firstly evaluated (EN12390-3 EN 12390-5) The main results on the differentmixtures are compared in Figures 5 6 and 7 As expectedboth the compressive and the flexural strength were found todecrease with an increase of crumb rubber content

In particular Figure 5 shows that the reductions in com-pressive strength tested on days 7 28 and 60 decreaseat a slower rate when the level of rubber is increasedHowever this change in the rate of loss of compressivestrength when rubber is included occurs at different rubberconcentrations for cement matrix composites with differentcuring periods It seems that the smaller the curing time thelower the loss in compressive strength when rubber level is

increasedMoreover Figure 7(a) clearly shows that for rubberpercentages higher than 30 the reduction in compressivestrength is quite drastic and the effect of rubber inclusionseems to be independent from the curing time Curing rubbercement composites increases the compressive strength up toa rubber percentage equal to 20 Figure 7(b) shows for eachcuring period the values of compressive strength against thedensities of rubber cement matrix composites According tothe acquired results mixes 10 and 20 are characterizedby larger values of compressive and flexural strength so theycould be potentially used to obtain rubber-concrete mixes forstructural applications by adding suitable amounts of coarseaggregates contrarily mixes 30 40 50 and 75 arecharacterized by very small values of compressive andflexuralstrength but lower volume mass so they could be potentiallyused as rubberized mortars for nonstructural applications

Since cement-based composites with rubber waste havelow compressive strength and a correlation exists betweencompressive strength and modulus of elasticity it is expectedthey also possess low modulus of elasticity In this study bothelastic dynamic modulus (MED) and secant elastic modulus


0

1

2

3

4

5

6

7

8

9

Flex

ural

stre

ngth

(MPa

)Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Figure 6 Flexural strength of rubber cement composites on day 60

000

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60 70

Time (days)

Mix TQMix 10Mix 20

Mix 30Mix 40Mix 50Mix 75

Com

pres

sive s

treng

th (M

pa)

(a)

0

10

20

30

40

50

60

1000 1500 2000 2500


Density (kgm3)

Com

pres

sive s

treng

th (M

pa)

(b)

Figure 7 Compressive strength of rubber cement composites against (a) curing time (b) density

(MES) were tested according to UNI 9524 and UNI 6556respectively The main results on the different mixtures aresummarized in Figures 8 9 and 10

Figures 8 and 10(a) show that both MED and MESdecrease significantly with increased quantities of rubberaggregate replacement The explanation for this behavior isrelated to the low modulus of elasticity of rubber waste andto the poor development of the interfacial transition zone

Tests regarding the hardened properties included also theinvestigation of shrinkage weight loss flexural behavior andthermal conductivity

As to shrinkage it was assessed according toUNI 6687-73at 1 2 7 14 21 and 28 days As shown in Figure 11 the changein length at 28 days of all mixes was within the range (minus400)ndash(minus700) 120583mm except for mix 75 in which the change wasthe largest and reached the value minus1650 120583mmThis behavioris partly due to the lower modulus of elasticity of rubberaggregate with respect to ordinary fine aggregate moreover

in the proposedmixes as the rubber percentage was increasedthe amount of fine aggregate which has a minor capability ofdeformation and contrasts shrinkage was reducedThereforeshrinkage in rubber mortar was always larger with respectto ordinary mortar and in particular the phenomenon isaccentuated in mix 75 where fine aggregate was just 166of the initial amount included in mix TQ On the contraryas rubber powder was added the weight loss in time becamesmaller as shown in Figure 12

Theweight loss at 28 days of allmixeswaswithin the rangeminus6 minus7 except for mix 75 in which the change was thesmallest (minus4) This result was to be expected consideringthat mix 75 is characterized by the lowest watercementratio

Four-point flexure tests were carried out according toASTM C 1018-97 The load and the deflection were digitallyrecorded at the rate of 1 data point per second The corre-sponding load-deflection curves for all mixes are reported


0

5

10

15

20

25

30

MED

(GPa

)

7 days28 daysgt28 days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Figure 8 MED of rubber cement composites on days 7 28 and gt28

000

500

1000

1500

2000

2500

3000

0 7 14 21 28 35 42 49

Time (days)

MED

(GPa

)

Mix TQMix 10Mix 20


(a)

0

5

10

15

20

25

30

35

1000 1500 2000 2500

7 days28 days

Density (kgm3)

MED

(GPa

)

(b)

Figure 9 MED of rubber cement composites against (a) curing time (b) density

in Figure 13 Increasing the rubber percentage induced areduction of the peak load and of the overall load bearingcapacity In mixes 10 and 75 the drop in peak load wasrespectively 50 and 14 with respect to mix TQ Thispoor mechanical behavior is connected to the simultaneouscompressive strength drop In contrast to that a significantstrain capacity gain was recorded in rubber cement-basedmixes in particular in mixes with rubber aggregate rates ge30 For example the strain capacities ofmixes incorporating

20 and 40 of rubber aggregates are respectively twiceand twenty times the mix TQ value of control While theflexure stiffness can be correlated with the low modulus ofelasticity the improved strain capacity can be interpretedas a consequence of the rubber aggregates and their effecton the stress field when the first microcracks run into thematrix-rubber aggregate interface Rubber aggregate can besupposed to act like a hole at the crack tip and this may resultin a mechanism hindering and delaying the propagation of


0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)

Figure 10 (a) MES of rubber cement composites on day 60 (b) MES on day 28 against density

1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)

Figure 11 Shrinkage for rubber cement composites at 1 2 7 14 21 and 28 days

Wei

ght l

oss (

)

Mix TQMix 10Mix 20Mix 30

Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000

Figure 12 Weigth loss for rubber cement composites at 1 2 7 14 21 and 28 days (119879 = 20∘C UR = 50)


0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN

)Mix TQMix 10Mix 20Mix 30

Mix 40Mix 50Mix 75

Figure 13 Flexure load-deflection primary curves for rubber cement composites

000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)

Figure 14 (a) Thermal conductivity for rubber cement composites on day 60 (b) thermal conductivity against density

microcracks As a consequence the use of rubber aggregatesshould be considered as a suitable solution for improving theductility of cement-based materials

Thermal resistance was assessed according to UNI EN12664 The results obtained on day 60 are summarized inFigure 14 It emerges that the addition of rubber aggregatessignificantly improves the thermal insulation of cementmatrix composites In particular the thermal conductivitiesofmix 10 and 75 are respectively 23 and 53 lower thanthat ofmix TQAs shown in Figure 14(b) this behavior can becorrelated to the density reduction as the rubber percentageincreases

33 Durability Properties The rapid freezing and thawingdurability of rubber cement matrix composites was firstlyinvestigated according to UNI EN 12390-9 The resultsshowed good durability properties for all mixtures in whichno variations in terms of mass and strength were observedat the end of freezing and thawing cycles On the contrary asshown in Figure 15 a slightly chipped surfacewith an increasein scaling equal to 0036 kgm2 was found in the case ofmix TQ (scaling gives an evaluation of the surface exposedto freezing and thawing cycles as measured by the loss of

weight) So rubber mortars performed better under freeze-thaw conditions than plain mortar showing that there is apotential for using rubber aggregate as a freeze-thaw resistingagent in cement-based materials

The results related to the exposure of the proposed mixesto sulfate attack according to CENTR 15697 prescriptionsrevealed a worse performance As shown in Figure 16 allmixes resulted vulnerable to sulfate attack in terms of reduc-tion of compressive strengthThe worst results were obtainedfor mix 20 in which the compressive strength decreasedfrom 33MPa to 8MPa

Finally the chloride permeability was assessed accordingto the Nordtest Method ISSN 0283-7153 As shown in Figure17 incorporating in cement composites rubber aggregateswith a percentage up to 50 contributes to the reductionof the chloride ion diffusion coefficient In particular thechloride ion diffusion coefficients of mixes 10 and 50 arerespectively 77 and 4615 lower than that of mix TQTheabove results can be explained admitting a relation betweenresistance to chloride ion penetration and watercementratio the higher the watercement ratio the higher theporosity of the cement matrix and the chloride ion diffusioncoefficient Nevertheless this behavior seems to be valid for


Figure 15 Freeze-thaw resistance mix TQ

000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)

Figure 16 Exposure of rubber cement composites to sulfate attack (a) compressive strength without and with sulfate attack (b) loss ofcompressive strength

rubber percentages up to 30 for higher contents of rubberaggregates the chloride ion diffusion coefficient increasesexceeding the mix TQ value in correspondence of a percent-age equal to 75 In the case of high contents of rubberthe rubber-cement matrix interface probably provides apreferential path to the permeation of chloride ions

4 Conclusions

The results presented in this paper show that the incor-poration in cement-based materials of rubber aggregatesobtained from waste tires can be a suitable solution forsome engineering manufactures simultaneously offering anopportunity to recycle nonreusable tires At the aim toobtain a complete characterization of the analyzed cementmatrix composites several experimental tests to assess the

mechanical and durability properties both on the fresh andthe hardened state were carried out Different percentages ofrubber particles from 0 to 75 were used in the cement-based mixes and for each percentage the suitable amountof sand was investigated by experimental sensitivity testsin order to achieve the best performances Despite somedrawbacks such as the decrease in compressive and flexuralstrengths the high shrinkage and the vulnerability to sulfateattack the tests demonstrate that the proposed rubber cementcomposites possess interesting properties that can be usefulespecially for nonstructural applications Mixes containingrubber up to about 50 are characterized by highworkabilitylight weight high ductility low thermal conductivity goodfreeze-thaw resistance and good resistance to chloride ionpenetration The above topics make the proposed rubbercement composites particularly feasible for non-load-bearing


000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Figure 17 Chloride ion diffusion coefficient for rubber cementcomposites

purposes in regions with harsh environmental conditions asin the case of roadway applications paving slabs flowableand trench fills insulating barriers and curtain walls Rubbercement-based compositesmay also be useful for architecturalapplications such as nailing mortar false facades stonebacking and interior constructions

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] E Ganjian M Khorami and A A Maghsoudi ldquoScrap-tyre-rubber replacement for aggregate and filler in concreterdquo Con-struction and Building Materials vol 23 no 5 pp 1828ndash18362009

[2] H L Chou C-K Lu J-R Chang and T M Lee ldquoUse of wasterubber as concrete additiverdquoWaste Management and Researchvol 25 no 1 pp 68ndash76 2007

[3] H A Toutanji ldquoThe use of rubber tire particles in concrete toreplace mineral aggregatesrdquo Cement and Concrete Compositesvol 18 no 2 pp 135ndash139 1996

[4] Z K Khatib and F M Bayomy ldquoRubberized Portland cementconcreterdquoASCE Journal ofMaterials in Civil Engineering vol 11no 3 pp 206ndash213 1999

[5] R Siddique and T R Naik ldquoProperties of concrete containingscrap-tire rubbermdashan overviewrdquo Waste Management vol 24no 6 pp 563ndash569 2004

[6] D Fedroff S Ahmad and B Z Savas ldquoMechanical propertiesof concrete with ground waste tire rubberrdquo TransportationResearch Board Report No 1532 Transportation ResearchBoard Washington DC USA 1996

[7] M A Aiello and F Leuzzi ldquoWaste tyre rubberized concreteproperties at fresh and hardened staterdquoWasteManagement vol30 no 8-9 pp 1696ndash1704 2010

[8] M A Aiello F Leuzzi G Centonze and A Maffezzoli ldquoUse ofsteel fibres recovered from waste tyres as reinforcement in con-crete pull-out behaviour compressive and flexural strengthrdquoWaste Management vol 29 no 6 pp 1960ndash1970 2009

[9] G Centonze M Leone and M A Aiello ldquoSteel fibers fromwaste tires as reinforcement in concrete a mechanical charac-terizationrdquoConstruction and BuildingMaterials vol 36 pp 46ndash57 2012

[10] N Segre and I Joekes ldquoUse of tire rubber particles as additionto cement pasterdquo Cement and Concrete Research vol 30 no 9pp 1421ndash1425 2000

[11] F Hernandez-Olivares G Barluenga M Bollati and BWitoszek ldquoStatic and dynamic behaviour of recycled tyrerubber-filled concreterdquo Cement and Concrete Research vol 32no 10 pp 1587ndash1596 2002

[12] N N Eldin andA B Senouci ldquoRubber-tire particles as concreteaggregaterdquo Journal of Materials in Civil Engineering vol 5 no4 pp 478ndash496 1993

[13] HHuynhD Raghavan andC Ferraris ldquoRubber particles fromrecycled tires in cementitious composite materialsrdquo Tech RepNISTIR 5850 R 1996

[14] N I Fattuhi and L A Clark ldquoCement-based materials contain-ing shredded scrap truck tyre rubberrdquo Construction and Build-ing Materials vol 10 no 4 pp 229ndash236 1996

[15] I B Topcu ldquoThe properties of rubberized concretesrdquo Cementand Concrete Research vol 25 no 2 pp 304ndash310 1995

[16] P Sukontasukkul and C Chaikaew ldquoProperties of concretepedestrian block mixed with crumb rubberrdquo Construction andBuilding Materials vol 20 no 7 pp 450ndash457 2006

[17] M K Batayneh I Marie and I Asi ldquoPromoting the use ofcrumb rubber concrete in developing countriesrdquo Waste Man-agement vol 28 no 11 pp 2171ndash2176 2008

[18] I B Topcu andN Avcular ldquoAnalysis of rubberized concrete as acomposite materialrdquo Cement and Concrete Research vol 27 no8 pp 1135ndash1139 1997

[19] B I Lee L Burnett T Miller B Postage and J Cuneo ldquoTyrerubbercement matrix compositesrdquo Journal of Materials ScienceLetters vol 12 no 13 pp 967ndash968 1993

[20] E Parant P Rossi and C Boulay ldquoFatigue behavior of a multi-scale cement compositerdquoCement and Concrete Research vol 37no 2 pp 264ndash269 2007

[21] K-R Wu D Zhang and J-M Song ldquoProperties of polymer-modified cement mortar using pre-enveloping methodrdquoCement and Concrete Research vol 32 no 3 pp 425ndash4292002

[22] H S Lee H Lee J S Moon and H W Jung ldquoDevelopment oftire-added latex concreterdquo ACI Materials Journal vol 95 no 4pp 356ndash364 1998

[23] QWMa and J C Yue ldquoEffect onmechanical properties of rub-berized concrete due to pretreatment of waste tire rubber withNaOHrdquoAppliedMechanics andMaterials vol 357-360 pp 897ndash904 2013

[24] F Hernandez-Olivares and G Barluenga ldquoFire performanceof recycled rubber-filled high-strength concreterdquo Cement andConcrete Research vol 34 no 1 pp 109ndash117 2004

[25] M C Bignozzi and F Sandrolini ldquoTyre rubber waste recyclingin self-compacting concreterdquo Cement and Concrete Researchvol 36 no 4 pp 735ndash739 2006

[26] S Li J Hu F Song and X Wang ldquoInfluence of interface modi-fication and phase separation on damping properties of epoxyconcreterdquo Cement and Concrete Composites vol 18 no 6 pp445ndash453 1996

[27] G Li M A Stubblefield G Garrick J Eggers C Abadie and BHuang ldquoDevelopment of waste tire modified concreterdquo Cementand Concrete Research vol 34 no 12 pp 2283ndash2289 2004


[28] C Albano N Camacho J Reyes J L Feliu andM HernandezldquoInfluence of scrap rubber addition to Portland I concrete com-posites destructive and non-destructive testingrdquo CompositeStructures vol 71 no 3-4 pp 439ndash446 2005

[29] A Benazzouk O Douzane K Mezreb and M QueneudecldquoPhysico-mechanical properties of aerated cement compositescontaining shredded rubber wasterdquo Cement and Concrete Com-posites vol 28 no 7 pp 650ndash657 2006

[30] H Rostami J Lepore T Silverstraim and I Zundi ldquoUse ofrecycled rubber tires in concreterdquo in Proceedings of the Interna-tional Conference on Concrete R K Dhir Ed pp 391ndash399University of Dundee Scotland UK 2000

[31] I B Topcu and A Demir ldquoDurability of rubberized mortar andconcreterdquo ASCE Journal of Materials in Civil Engineering vol19 no 2 pp 173ndash178 2007

[32] G Skripkiunas A Grinys and E Janavicius ldquoPorosity and dur-ability of rubberized concreterdquo in Proceedings of the 2nd Inter-national Conference on Sustainable Construction Materials andTechnologies pp 1243ndash1253 Ancona Italy June 2010

[33] L Zheng X SharonHuo andY Yuan ldquoExperimental investiga-tion on dynamic properties of rubberized concreterdquo Construc-tion and Building Materials vol 22 no 5 pp 939ndash947 2008

[34] J G M vanMier S P Shah M Arnaud et al ldquoStrain-softeningof concrete in uniaxial compressionmdashreport of the RoundRobin Test carried out by RILEM TC 148-SSCrdquo Materials andStructures vol 30 no 198 pp 195ndash209 1997

[35] A Turatsinze J L Granju and S Bonnet ldquoPositive synergybetween steel-fibres and rubber aggregates effect on the resis-tance of cement-based mortars to shrinkage crackingrdquo Cementand Concrete Research vol 36 no 9 pp 1692ndash1697 2006

[36] A Fiore G C Marano P Monaco and A Morbi ldquoPreliminaryexperimental study on the effects of surface-applied photocata-lytic products on the durability of reinforced concreterdquo Con-struction and Building Materials vol 48 pp 137ndash143 2013

[37] A S Benosman H Taibi M Mouli M Belbachir and Y Sen-hadji ldquoDiffusion of chloride ions in polymer-mortar compo-sitesrdquo Journal of Applied Polymer Science vol 110 no 3 pp1600ndash1605 2008

[38] M Bravo and J de Brito ldquoConcrete made with used tyre aggre-gate durability-related performancerdquo Journal of Cleaner Pro-duction vol 25 pp 42ndash50 2012

[39] A Fiore D Foti P Monaco D Raffaele and G Uva ldquoAnapproximate solution for the rheological behavior of non-homogeneous structures changing the structural system duringthe construction processrdquo Engineering Structures vol 46 pp631ndash642 2013

[40] A Fiore G C Marano and P Monaco ldquoEarthquake-inducedlateral-torsional pounding between two equal height multi-storey buildings undermultiple bi-directional groundmotionsrdquoAdvances in Structural Engineering vol 16 no 5 pp 845ndash8662013

[41] A Fiore P Monaco and D Raffaele ldquoViscoelastic behaviourof non-homogeneous variable-section beams with post-ponedrestraintsrdquo Computers and Concrete vol 9 no 5 pp 357ndash3742012

[42] A Fiore and P Monaco ldquoAnalysis of the seismic vulnerabilityof the ldquoQuinto Orazio Flaccordquo school in Bari (Italy)rdquo IngegneriaSismica vol 2011 no 1 pp 43ndash62 2011

[43] A Fiore and P Monaco ldquoEarthquake-induced poundingbetween the main buildings of the ldquoQuinto Orazio Flaccordquoschoolrdquo Earthquake and Structures vol 1 no 4 pp 371ndash3902010

[44] A Fiore and P Monaco ldquoPOD-based representation of thealongwind equivalent static force for long-span bridgesrdquo Windand Structures vol 12 no 3 pp 239ndash257 2009

[45] G C Marano R Greco G Quaranta A Fiore J Avakian andD Cascella ldquoParametric identification of nonlinear devices forseismic protection using soft computing techniquesrdquo AdvancedMaterials Research vol 639-640 no 1 pp 118ndash129 2013

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



25ndash30mm) used to replace the coarse aggregates crumbrubber (3ndash10mm) used to replace sand ash rubber (smallerthan 1mm) used as a filler

Crumbed rubber (CR) from vehicle tyres mixed inwith cement composites induces serious variations in thematerial properties The results of many studies demonstratethat the partial or total replacement of aggregates withrubber negatively affects mechanical properties of cement-based materials [10ndash12] proportionally to the quantity ofrubber scraps Also the size of rubber scraps affects strengthcoarse scraps reduce compressive strength more than finescraps [12ndash17] Eldin and Senouci [12] determined that whencoarse aggregate was replaced in full with mechanicallycrumbled waste rubber the compressive strength droppedby 85 whereas splitting tensile strength went down by50 However when fine aggregate was replaced in fullwith waste rubber the authors observed lower reductionin compressive strength (65) and the same reduction insplitting tensile strength (50) Studies conducted by theauthors Topcu and Avcular [18] Lee et al [19] and Parantet al [20] showed greater reduction in compressive strengthwhen coarse aggregate was replaced with CR compared to thereplacement of fine aggregate

Segre and Joekes [10] analysed the change in compressiveand bending strength of cement composites with CR added at10 of the total aggregate content To obtain a better adhesionof cement matrix and rubber the authors soaked rubberparticles in NaOH solution Scanning Electron Microscopytesting has shown that rubber particles which were soakedin NaOH solution were much more covered with cementhydrates and there were more newly formed hydrationproducts on the surface of soaked rubber particles comparedto the particles that were not soaked in NaOH solution Nev-ertheless the compressive strength of cement-basedmaterialwhere 10 of the total aggregate content was rubber particlesnot soaked in NaOH reduced by 33 compared to controlspecimens the same reduction was observed in cementmaterial with rubber particles soaked in NaOH solutionThehighest bending strength was observed in mixtures wherewaste rubber not soaked in NaOH solution was used Thebending strength of such mixes compared to control speci-mens and to cement composite containing rubber soaked inNaOH solution was higher by 94 and 10 respectivelyThereduction in compressive strength and increase in bendingstrength in cement-based materials with rubber wasteadditives were also detected by Chinese researchers [21ndash23]whereas tests of other authors [11 24ndash26] demonstratedthat both bending strength and compressive strength inconcrete with CR were lower compared to concretes withoutCR

Many authors analysed the effect of CR on concretersquossplitting tensile strength [2 11 17 27 28] Comprehensiveanalysis of literature has revealed that tensile strength reduceswith the addition of CR

The decrease in strength can be thus explained by the lackof bonding and the low adhesion between the rubber crumband the cement matrix [5 10 27] The reduction in concretestrength can also be ascribed to the circumstance that rubberparticles have lower strength than concrete matrix around

them and thus when force is applied the cracks first of allappear in the contact zone of rubber and concrete matrix[8 12 18 19] Cracks gradually propagate under load untilconcrete crumbles Such rubber performance discrepancymakes rubber particles similar to voids in cement composites[12 25 29]

In addition not only strength but also workabilitydecreases with the increasing of the percentage of rubber dueto the increasing viscosity of the mixture [4 12]

On the other hand there are several other properties ofconcrete that benefit by the presence of crumb rubber Onesignificant benefit is the property that rubber reduces massdensity [15 30] and increases deformability and ductilityso it is useful in elements that do not require an elevatedstrength but require instead the reduction of vibrations orthe increasing of resilience durability and deformability [31]and absorption of low-frequency noise [32]

Hernandez-Olivares et al [11] investigated the Youngdynamicmodulus of rubber-filled concretewith different vol-umetric fraction at low frequencies and the dissipated energyin viscoelastic regime and under compressive dynamic loadthey dealt only with specimens with low volumetric fractionof tire rubber

Zheng et al [33] tested simply supported beams withdifferent volumetric fraction of tire rubber to underline therelationships between damping ratio in small deformationand the size and amount of rubber scraps they also testedthe dynamic modulus of rubberized concrete making acomparison with the static modulus It was observed that thedamping ratio of rubberized concrete improved while thedynamic modulus elasticity of rubberized concrete resultedlower than that of plain concrete

Some authors have also discussed the time-dependentproperties of rubberized concrete which may be critical insome cases A study of van Mier et al [34] for example hasrevealed that the significant difference in Poissonrsquos ratio ofrubber particles and the cement-matrix encourages prema-ture cracking However Turatsinze et al [35] indicated thatthe higher the content of rubber shreds the smaller the cracklength and width due to shrinkage and the onset time ofcracking was more delayed

Just a few studies are available in literature on the topicof durability [36] of rubber-cement mixes They mainlyfocus on the abrasion resistance and freeze-thaw exposureperformance Sukontasukkul and Chaikaew [16] mentionedthat crumb concrete blocks show less abrasion resistanceand also that increasing the crumb rubber content leadsto a reduction in the abrasion resistance This result wasconfirmed by other authors Topcu and Demir [31] showedthat a high volume replacement of sand by rubber waste hadlower durability performance assessed by freeze-thaw expo-sure seawater immersion and high temperature cycles As tochloride permeability some results are discussed dealing withpolyethylene terephthalate bottle (PET) wastes Benosman etal [37] reported that the partial replacement of cement byPET wastes led to a reduction of the chloride ion diffusioncoefficient Bravo and de Brito performed tests for shrinkagewater absorption carbonation and chlorides penetrationresistance for concrete mixes in which just 5 10 and 15


















000

1000

2000

3000

4000

5000

6000

7000

8000

Spre

adin

g (c

m)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Spreading 0998400

Spreading 30998400

Spreading 60998400


900

1400

1900

2400

(kg

m3)

Mixtures

0998400

30998400

60998400

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ



35

30

25

20

15

10

5

0

Air

cont

ent (

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ









0

1

2

3

4

5

6

7

8

9

Flex

ural

stre

ngth

(MPa

)Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60 70

Time (days)

Mix TQMix 10Mix 20


Com

pres

sive s

treng

th (M

pa)

(a)

0

10

20

30

40

50

60

1000 1500 2000 2500


Density (kgm3)

Com

pres

sive s

treng

th (M

pa)

(b)










0

5

10

15

20

25

30

MED

(GPa

)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

0 7 14 21 28 35 42 49

Time (days)

MED

(GPa

)

Mix TQMix 10Mix 20


(a)

0

5

10

15

20

25

30

35

1000 1500 2000 2500

7 days28 days

Density (kgm3)

MED

(GPa

)

(b)





0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)


1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)


Wei

ght l

oss (

)


Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000



0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation


























000

1000

2000

3000

4000

5000

6000

7000

8000

Spre

adin

g (c

m)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

Spreading 0998400

Spreading 30998400

Spreading 60998400


900

1400

1900

2400

(kg

m3)

Mixtures

0998400

30998400

60998400

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ



35

30

25

20

15

10

5

0

Air

cont

ent (

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ









0

1

2

3

4

5

6

7

8

9

Flex

ural

stre

ngth

(MPa

)Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60 70

Time (days)

Mix TQMix 10Mix 20


Com

pres

sive s

treng

th (M

pa)

(a)

0

10

20

30

40

50

60

1000 1500 2000 2500


Density (kgm3)

Com

pres

sive s

treng

th (M

pa)

(b)










0

5

10

15

20

25

30

MED

(GPa

)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

0 7 14 21 28 35 42 49

Time (days)

MED

(GPa

)

Mix TQMix 10Mix 20


(a)

0

5

10

15

20

25

30

35

1000 1500 2000 2500

7 days28 days

Density (kgm3)

MED

(GPa

)

(b)





0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)


1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)


Wei

ght l

oss (

)


Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000



0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










35

30

25

20

15

10

5

0

Air

cont

ent (

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


0

10

20

30

40

50

60

Com

pres

sive s

treng

th (M

Pa)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ









0

1

2

3

4

5

6

7

8

9

Flex

ural

stre

ngth

(MPa

)Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60 70

Time (days)

Mix TQMix 10Mix 20


Com

pres

sive s

treng

th (M

pa)

(a)

0

10

20

30

40

50

60

1000 1500 2000 2500


Density (kgm3)

Com

pres

sive s

treng

th (M

pa)

(b)










0

5

10

15

20

25

30

MED

(GPa

)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

0 7 14 21 28 35 42 49

Time (days)

MED

(GPa

)

Mix TQMix 10Mix 20


(a)

0

5

10

15

20

25

30

35

1000 1500 2000 2500

7 days28 days

Density (kgm3)

MED

(GPa

)

(b)





0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)


1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)


Wei

ght l

oss (

)


Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000



0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0

1

2

3

4

5

6

7

8

9

Flex

ural

stre

ngth

(MPa

)Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

3500

0 10 20 30 40 50 60 70

Time (days)

Mix TQMix 10Mix 20


Com

pres

sive s

treng

th (M

pa)

(a)

0

10

20

30

40

50

60

1000 1500 2000 2500


Density (kgm3)

Com

pres

sive s

treng

th (M

pa)

(b)










0

5

10

15

20

25

30

MED

(GPa

)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

0 7 14 21 28 35 42 49

Time (days)

MED

(GPa

)

Mix TQMix 10Mix 20


(a)

0

5

10

15

20

25

30

35

1000 1500 2000 2500

7 days28 days

Density (kgm3)

MED

(GPa

)

(b)





0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)


1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)


Wei

ght l

oss (

)


Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000



0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0

5

10

15

20

25

30

MED

(GPa

)


Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ


000

500

1000

1500

2000

2500

3000

0 7 14 21 28 35 42 49

Time (days)

MED

(GPa

)

Mix TQMix 10Mix 20


(a)

0

5

10

15

20

25

30

35

1000 1500 2000 2500

7 days28 days

Density (kgm3)

MED

(GPa

)

(b)





0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)


1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)


Wei

ght l

oss (

)


Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000



0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0

5

10

15

20

25

MES

(GPa

)60

days

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

0

5

10

15

20

25

1000 1500 2000 2500

MES

(GPa

)28

days

Density (kgm3)

(b)


1 2 7 14 21 28

Time (days)

Mix TQMix 10Mix 20


minus1800

minus1600

minus1400

minus1200

minus1000

minus800

minus600

minus400

minus200

0

Shrin

kage

(120583m

m)


Wei

ght l

oss (

)


Mix 40Mix 50Mix 75

1 2 7 14 21 28

Time (days)

minus700

minus600

minus500

minus400

minus300

minus200

minus100

000



0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0

2

4

6

8

10

12

14

0 100 200 300 400 500 600 700 800 900 1000

Arrow (120583m)

Load

(kN


Mix 40Mix 50Mix 75


000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

1000 1500 2000000

020

040

060

080

100

120

140

Ther

mal

cond

uctiv

ity (W

mK)

Density (kgm3)

(b)










000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











000

500

1000

1500

2000

2500

3000

3500

4000

Rc

(MPa

)

RcSO4

Rc-ref

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(a)

minus3000

minus2500

minus2000

minus1500

minus1000

minus500

000R

c(M

Pa)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ

(b)



4 Conclusions




000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










000E + 00

100E minus 11

200E minus 11

300E minus 11

400E minus 11

500E minus 11

600E minus 11

700E minus 11

Diff

usio

n co

effici

ent (

m2s

)

Mixtures

Mix

10

Mix

20

Mix

30

Mix

40

Mix

50

Mix

75

Mix

TQ





References

















































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation






























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









Research Article On the Fresh/Hardened Properties of...

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