Research Article Self-Shrinkage Behaviors of Waste Paper

Research ArticleSelf-Shrinkage Behaviors of Waste Paper Fiber ReinforcedCement Paste considering Its Self-Curing Effect at Early-Ages

Zhengwu Jiang1 Xiuyan Guo12 Wenting Li1 and Qing Chen1

1Key Laboratory of Advanced Civil Engineering Materials Ministry of Education Tongji University Shanghai 200092 China2School of Mechanical amp Electrical Engineering Jinggangshan University Jirsquoan Jiangxi 343009 China

Correspondence should be addressed to Zhengwu Jiang jzhwtongjieducn

Received 10 February 2016 Revised 8 April 2016 Accepted 27 April 2016

Academic Editor Zhouyang Xiang

Copyright copy 2016 Zhengwu Jiang et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The aim of this paper was to study how the early-age self-shrinkage behavior of cement paste is affected by the addition of the wastepaper fibers under sealed conditions Although the primary focus was to determine whether the waste paper fibers are suitableto mitigate self-shrinkage as an internal curing agent under different adding ways evaluating their strength pore structure andhydration properties provided further insight into the self-cured behavior of cement paste Under the wet mixing condition thewaste paper fibers could mitigate the self-shrinkage of cement paste and at additions of 02 by mass of cement the waste paperfibers were found to show significant self-shrinkage cracking control while providing some internal curing In addition the self-curing efficiency results were analyzed based on the strength and the self-shrinkage behaviors of cement paste Results indicatedthat under a low water cement ratio an optimal dosage and adding ways of the waste paper fibers could enhance the self-curingefficiency of cement paste

1 Introduction

Because of the need of long spans towering and overloadingand harsh conditions in modern engineering the high-performance concrete (HPC) has been widely used in theinfrastructure such as bridges high-rise buildings port andunderground projects due to the high strength and highperformance [1 2] However self-desiccation leading to self-shrinkage causes the early cracks of concrete which havebeen recognized to be a major shortcoming of HPC [3ndash5]

Because of a low water-binder ratio of HPC a largeamount of unhydrated cement within concrete can attractwater from the capillary and begin to hydrate Yet externalmoisture is difficult to penetrate into the inside of the concretedue to the compacting concrete structure and the capillarydehydrates and forms a vacuum even leading to the self-shrinkage of concrete With the early hardening of con-crete the shrinkage deformation is greater than the ultimatestretching deformation which always causes the crackingand then decreases the permeability and the carbonationresistance of concrete Thus the self-desiccation shrinkage ofconcrete is closely related to the drop of its internal relative

humidity this is confirmed in the previous studies [6ndash8] Inorder to effectively control and improve the self-shrinkage ofconcrete an absorbent polymer as a self-curing agent is devel-oped to improve the hydration degree of concrete and reducethe compressive stress and the sensitivity to cracking [9ndash11]

Cellulose fibers that owned the amorphous structureare evenly dispersed in concrete which efficiently restraincrack formation and delay crack growth [12 13] In additioncellulose fibers have a nature hydrophilic property [14]which plays a key role in the concrete Internal curingis explored from water-saturated porous cellulose fibers toprovide additional curingwater in the early hydration processof concrete This strategy is effective because the additionalcuring water can replenish the emptying pores more quicklythan traditional external curing water [15] This processaccelerates hydration of cement and then enhances the inter-facial cohesiveness between cellulose fibers and cementingmaterial which increases the compactness improves thepermeability resistance of concrete and gives the concretebetter durability and service life [16]

Waste paper fibers (WPFs) are affiliated with cellulosefibers and have their advantages such as an amorphous

Hindawi Publishing CorporationInternational Journal of Polymer ScienceVolume 2016 Article ID 8690967 12 pageshttpdxdoiorg10115520168690967

2 International Journal of Polymer Science

25120583m

(a)

25120583m

(b)

Figure 1 SEM surface morphologies of WPFs

Table 1 Chemical component of the waste paper fibers (wt)

Component Cellulose Hemicellulose FillersContent () sim93 sim5 sim2

structure and a nature hydrophilic property [17] Theoreti-cally speaking the WPFs can be used as a substitute for thecellulose fibers and applied in concrete Moreover the WPFsused in concrete do not require the use of the deinking andbleaching processes thereby greatly reducing the emissionsof hazardous substances in the wastewater [18] Previousstudies had shown that cheap WPFs could enhance theconcrete [19] and reduce the dosage of cement [20] themechanical property and the durability of theWPFs concretewere also researched [21] However the use of the WPFs toenhance the shrinkage resistance and self-curing effect ofconcrete has not been yet reported This research aims tocontribute to filling this lack of knowledge

It is generally known that the shrinkage of concrete isinfluenced by many factors except low water ratios in orderto truly reflect the self-shrinkage and self-curing behaviorsof the WPFs reinforced cement-based materials the cementpaste instead of concrete is selected as the matrix which doesnot consider other factorsThe self-shrinkage and self-curingbehaviors of cement paste with the WPFs are researched inthis paper In addition the reasonable addition ways anddosage of WPFs in cement paste at a low water cement ratioare discussed which can provide theoretical basis for actualproduction

2 Experimental

21 Materials Waste paper fibers (WPFs) from newsprintwere pretreated and modified surfaces in our own lab [22]They have an average length of 16mm an average diameterof 24120583m and a specific surface area of 23m2gThe chemicalcontent of theWPFs was listed in Table 1 From the chart thecontent of cellulose was about 93 showing that the WPFsowned good alkali resistanceThe SEM surfacemorphologiesof WPFs were shown in Figure 1 The fiber bundle waslayered along the long end many microfibrils were produced

and exist on the fiber surfaces (Figure 1(a)) and the WPFthat owned porous hollow structure was shown quite clearly(Figure 1(b)) which allows it to absorb and retain water

A Portland cement PII 525 and tap water were used inall mixes a polycarboxylic high-performance water-reducingagent (SD-600P-01) was used to adjust the workability ofcement paste and the fluidities of all the samples werecontrolled at 140 plusmn 10mm The chemical compositions ofclinker were listed in Table 2

22 Mix Design All the mixtures were designed to have afluidity indice of 140plusmn10mm Twomain differences betweenthe mixes were the dosage and the adding ways of the WPFsThe dosages of the WPFs were 01 02 03 and 04by mass of cement respectively Wet mixing and dry mixingwere implemented at a water cement ratio of 03 Amongthem wet mixing was that both the WPFs and the totalquotas of water were weighed firstly and then the fibers weresoaked in the normed water at least 30min until the WPFswere treated to be fully dispersible in water at which pointthis mixture was mixed with cement However dry mixingwas that the preweighed dry WPFs were mixed with cementfirstly and then suitable water was added to compound Themix designs of cement pastes were shown in Table 3

23 Testing Methods To improve the testing accuracy threesame specimens of every curing age were prepared and testedfor each sample as described below

231 Compressive Strength and Flexural Strength Accordingto the Chinese National Standard GBT 17671-1999 [23]cement pastes were casted in 40mm times 40mm times 160mmmolds and vibrated at the time of casting to remove airbubbles The molded pastes were kept at temperature 20 plusmn2

∘C and relative humidity exceeding 95 for 24 h and thenremoved from the molds The demoulded samples weresealed with high density polypropylene film and epoxy resinsealant and then cured in a room with temperature 20∘C andrelative humidity 60 for the set ages The compressive andflexural strengths of all specimens were determined usinga ACE-201 strength test machine Three same specimens ofevery curing age were measured and the arithmetic average

International Journal of Polymer Science 3

Table 2 Chemical components of clinker (wt)

Components SiO2

Al2O3

Fe2O3

CaO MgO SO3

K2O Na

2O Total

Content () 2174 506 356 666 088 081 055 005 9925

Table 3 Mix proportion of cement paste

Code WC Water(kgm3) Cement(kgm3) Superplasticizer (bymass of cement)permil

WPFs dosage (bymass of cement)

WPFs addingway

A0 025 200 800 28 mdash mdashA1 025 200 800 35 01 Wet mixingA2 025 200 800 42 02 Wet mixingA3 025 200 800 5 03 Wet mixingA4 025 200 800 58 04 Wet mixingB0 03 240 800 18 mdash mdashB1 03 240 800 22 01 Wet mixingB2 03 240 800 28 02 Wet mixingB3 03 240 800 35 03 Wet mixingB4 03 240 800 44 04 Wet mixingB5 03 240 800 3 02 Dry mixing

was taken as the ultimate strength of cement paste Based onthese data the compressive to flexural strength (120590

119862120590

119865) was

calculated Finally the central parts of specimens were driedand stored in alcoholic solution for micro measurements

232 Self-Shrinkage Characteristics According to the Chi-nese National Standard JGJT 70-2009 [24] all specimenswere casted in the 40mm times 40mm times 160mm shrinkagemolds and shocked slightly at the time of casting to removeair bubblesThemolded specimens were kept at 20plusmn 2∘C andrelative humidity exceeding 95 for 24 h and then removedfrom the molds and measured length (119871

0) All specimens

were sealed and cured under the same conditions as thosementioned above The length of specimen cured for each age(119871119905) was measured The linear shrinkage strain of cement

paste was determined according to

120576

119886119905=

119871

0minus 119871

119905

119871 minus 119871

119889

(1)

where 120576119886119905

is the linear shrinkage ratio of specimen curedfor 119905 days (119905 = 1 3 7 28 56 90) 119871

0is the initial length of

specimenwith feeder head119871119905is the actual length of specimen

cured for 119905 days (119905 = 1 3 7 28 56 90) 119871 is the length ofspecimen (160mm) and 119871

119889is the sum length of two feeder

heads buried in the specimen

233 Hydration Characteristics

(1) TG-DSC The contents of calcium hydroxide in the hard-ened cement paste were assessed by a thermogravimetry-differential scanning calorimetry (TG-DSC) To do so thespecimens were dried at 40∘C for approximately 24 h thesedried specimens were crushed pestled and sieved and smallparticles ranging from 200120583m to 500120583m were collected assamples In a thermal analysis about 30mg of a sample

was put in an alumina top-opened crucible and heated fromroom temperature to 850∘C at a rate of 10∘Cmin The weightloss data and energy compensation data were determinedand recorded for further analysis Nitrogen gas was chosenas the dynamic atmosphere and corundum as the referencematerial

The hydration degree of cement paste was quantitativelycalculated by the thermal analysis The following was thecalculating method [25]

119866

119905(CH) = Δ119898

119898

0

times

119872CH119899119872losstimes 100 (2)

Ca (OH)2997888rarr CaO +H

2O (3)

where Δ119898 is the loss of quality in the calculating temperaturerange 119898

0is the original quality 119872loss and 119872CH are the

molecular weights of the loss of gas (H2O) and predicted

component (Ca(OH)2) respectively and 119899 is the mole num-

ber of lost gas in one mole sample (119899 = 1)

(2) XRD Mineral phases of cement pastes were identified bya Dmax 2550VB3PClowast X-ray powder diffractometer (XRD)All samples were prepared as described above The patternsproduced using Cu-K-120572 radiation (120582 = 015418 nm) at 40 kVand 100mA were recorded in the range of 2120579 at 5∘sim70∘ in002∘ steps counting by 4 s per step

234 Pore Structure The pore structure of cement paste wasdetermined by a mercury intrusion porosimeter (PoremasterGT-60) Pore size is related to the pressure by Washburnrsquosequation which assumes that the pores have circular crosssections

119875 =

minus2120590

1015840 cos 120579119903

(4)


Table 4 The strengths of cement pastes at a different water cement ratio for sealed curing

Code WC WPF () Flexural strength (MPa) Compressive strength (MPa) 120590

119862120590

119865

1 d 3 d 7 d 28 d 90 d 1 d 3 d 7 d 28 d 90 d 1 d 3 d 7 d 28 d 90 dA0 025 mdash 109 116 108 81 175 726 882 903 1044 1138 664 759 83 128 65A1 025 01 114 125 113 101 168 746 890 914 1073 1159 655 713 81 106 69A2 025 02 118 132 129 126 165 769 894 950 1080 1205 65 68 73 86 73A3 025 03 102 125 120 106 151 738 859 940 1009 1104 727 69 78 95 73A4 025 04 87 98 97 91 148 711 822 869 942 1036 77 84 89 103 7B0 03 mdash 66 75 90 102 114 494 735 820 894 935 75 98 91 88 82B1 03 01 60 77 95 104 99 420 694 778 871 915 7 91 82 84 92B2 03 02 59 91 93 98 92 331 679 722 810 864 56 75 78 83 94B3 03 03 56 86 89 92 85 312 676 718 800 821 56 79 81 87 97B4 03 04 55 66 71 89 65 293 654 697 796 748 53 98 98 111 116

where 119875 is the pressure exerted (Nm2) 119903 is the pore radius(120583m) 120590 is the surface tension of mercury (Nm2) and 120579 is thecontact angle (∘)

In this study a maximum pressure of 14 times 108Nm2 wasapplied The surface tension 120590 of 0480Nm and the contactangle (120579) of 140∘ were used for the calculation of pore size

Small pieces of cement paste weighing 12 g obtained fromthe middle part of 60mm cement paste specimens were usedfor Mercury Intrusion Porosimetry (MIP) testing In orderto stop the hydration the specimens were dried at 105∘Cfor approximately 24 h until a constant weight was achievedand then they were kept in sealed containers until the dayof the test Two MIP tests were conducted for each sampleand the average values of the MIP results were used for datacomparison

3 Results and Discussion

31 Strength Cement-based material is typical heteroge-neous brittle materials shrinkage cracking is one of thesignificant factors of its failures To improve its brittlenesstoughness is especially important The 120590

119862120590

119865is one of the

toughness indices ofmaterials the lower the120590119862120590

119865 the better

the toughness and the stronger the shrinkage resistance ofmaterials

311 The Effect of the WPFs Dosage on Strength WPFs weremixed with cement using wet mixing dealing with strengthand compressive to flexural strength ratio 120590

119862120590

119865of samples

is as shown in Table 4At water cement ratio of 025 the flexural strengths of all

samples increased in the first three days and then decreasedgradually with curing age and the decline degrees of flexuralstrengths were different After curing for 28 d the flexuralstrengths of all samples were greatly raised The flexuralstrength of cement paste is influenced by hydration andwater cement ratio In principle the lower the water cementratio and the quicker the hydration process the higher theflexural strength The WPF has mainly an impact on theflexural strength of cement paste because of its absorbingand releasing moisture Before sealed curing for 3 d the

humidity dropped down and more gels were formed withhydration which made the flexural strength of specimenincrease However after curing for 3 d once the negativepressure water supply occurred theWPFwould release waterto compensate it The actual water cement ratio increasecaused by releasemoisturewas likely to play a leading roleOnthe one hand moisture from WPFs promoted the hydrationprocess and improved the flexural strength further on theother hand it is just because released moisture increasedthe actual water cement ratio causing the reduction of theflexural strength these two contradictory factors caused thedecrease of the flexural strength of specimen cured for 3ndash28 dAfter curing for 28 d the hydration forced the rapidwater lossofWPFs and formedmore hydration products which causedthe rapid growth of the flexural strength When the dosagesof the WPFs were 01sim03 by mass of cement the flexuralstrengths of cement pastes cured for 3 dsim28 d were higherthan those of control samples Among them the dosage of theWPFs was 02 by mass of cement and the flexural strengthof cement paste cured for 28 d was significantly the highestand increased by 556 However when the dosage of theWPFs was 04 the flexural strengths of cement pastes wereobviously lower than those of control samples except 28 dand thus under the quantity the WPFs had a negative effecton the flexural strength At the same water cement ratio thecompressive strengths of cement pastes increased with thedosage of theWPFs and reachedhighest at the dosage of 02However the flexural strengths of cement pastes were slightlylarger than those of control samples when water cement ratiowas 03 and the dosage of the WPFs was less than 02Besides the flexural strength and the compressive strengthof cement paste decreased with the dosage of the WPFs

Whatever water cement ratios when the dosage of theWPFswas 01sim03bymass of cement the120590

119862120590

119865of cement

paste cured for 3 dsim28 d was lower than that of standardsample When a water cement ratio was 025 the 120590

119862120590

119865of

cement paste containing 02WPFs was lowest and droppedby more than 30 percent when cement paste was cured for28 d as for the WPFs dosage of 03 the 120590

119862120590

119865of cement

paste cured for 1 d was higher than that of standard samplewhich could be because of experimental mistakes Howeverwhen cement paste was cured for 90 d the 120590

119862120590

119865of cement


Table 5 The strengths of cement pastes at a water cement ratio of 03 for sealed curing

Code WPFs () Adding ways Flexural strength (MPa) Compressive strength (MPa) 120590

119862120590

119865

1 d 3 d 7 d 28 d 90 d 1 d 3 d 7 d 28 d 90 d 1 d 3 d 7 d 28 d 90 dB0 mdash mdash 66 75 90 102 114 494 735 820 894 935 75 98 91 88 82B2 02 Wet mixing 59 91 93 98 92 331 679 722 810 864 56 75 78 83 94B5 02 Dry mixing 53 77 87 90 84 475 643 860 873 825 89 83 99 97 99

16

12

8

4

0

WC = 025

A0

0 10 20 30 40 50 60 70 80 90

Curing age (d)

A1 (01 WPFs)A2 (02 WPFs)


Shrin

kage

(Eminus4)

(a)

16

12

8

4

0

WC = 03

B0

0 10 20 30 40 50 60 70 80 90

Curing age (d)

B1 (01 WPFs)B2 (02 WPFs)


Shrin

kage

(Eminus4)

(b)

Figure 2 The shrinkages of cement pastes at a water cement ratio of 025 (a) and 03 (b)

paste containing WPFs was higher than that of standardsample which means that with the dosage of 01sim03 bymass of cement theWPFswere able to improve the toughnessof cement paste cured for early-age The lower the watercement ratio the better the WPFs improving the toughnessof cement paste In addition when the dosage of the WPFswas 02 by mass of cement the toughness of cement pastescured for early-age was optimal

312 The Effects of the WPFs Adding Ways on Strength Atwater cement ratio of 03 theWPFs of 02bymass of cementwere mixed with cement using wet mixing and dry mixingrespectively The strength and the 120590

119862120590

119865of cement pastes are

as shown in Table 5Throughout these data in Table 5 the values of compres-

sive strength had no obvious variety regulation but when theWPFs were added with wet mixing the flexural strengths ofcement pastes (B2)were higher than those of drymixing (B5)From 120590

119862120590

119865 we found that 120590

119862120590

119865of sample B2 cured within

28 days was lower than those of B0 and B5 which showedthat the WPFs could improve the toughness of cement pastebut the degree of improvement was about the adding waysof WPFs The adding ways of the WPFs directly affected thedispersion degree of fibers and then affected the performanceof cement paste It was difficult to disperse WPFs in thecondition of dry mixing causing WPFs to agglomerate in

matrix which was unfavorable to improve the toughness ofcement paste Thus compared with dry mixing the addingway of WPFs with wet mixing was suitable

32 Shrinkage Characteristics

321 The Effect of Fiber Dosage on the Self-Shrinkage It iswidely understood that adding cellulose fiber to cement-based materials can control the drying shrinkage crackingand the plastic shrinkage [26ndash28] In addition cellulose fiberscan be dispersed in hydrating cement paste and have thecapacity to absorb and release water to enhance the internalcuring and inhibit the self-shrinkage of cement paste [15]Figure 2 gives an overview on how the WPFs dosages affectthe shrinkage of cement paste at differentwater cement ratios

Figure 2(a) shows that theWPFs effectively decreased theshrinkage of cement paste at a water cement ratio of 025As mentioned previously the WPFs belong to the cellulosefibers which could absorb somewater andmaintain saturatedstate before being mixed with cement The humidity ofmatrix gradually dropped with the hydration of cement atthis point the WPFs would release moisture to compensateit and promote the hydration further More hydration gelswere generated and growing along the surface of the WPFs-like bridge which enhanced the strength and the shrinkageresistance However the reinforcing effects related to the


16

12

8

4

0

WC = 03

B0B2 (wet mixing)B5 (dry mixing)

0 10 20 30 40 50 60 70 80 90

Curing age (d)

Shrin

kage

(Eminus4)

Figure 3 The shrinkage of cement paste containing WPFs usingdifferent adding ways

dispersion of the WPFs Smaller amounts of the WPFs haveno effect on antishrinkage while bigger amounts of theWPFswere not distributed in cement paste well causing the weakerantishrinkage When the dosage of the WPFs was 02 bymass of cement the shrinkage of cement paste was lowestThe shrinkage of cement paste cured for 1 d decreased by 67based on control sample and when cement paste was curedfor 3 d and 7 d the shrinkages of cement paste were decreasedby 74 and 50 respectively Although the shrinkage ofcement paste containing 04 WPFs was also lower theflexural strength of this sample decreased by about 30whenit was cured for 3 days (Table 3) causing the negative impacton paste so excessive amounts of WPFs were improper

Compared with Figure 2(a) although adding the WPFsto cement paste reduced the shrinkage of paste the effect wasobviously smaller at a water cement ratio of 03 (Figure 2(b))When the WPFs dosage was 02 by mass of cementsimilarly the cement paste had a minimum linear shrinkagestrain When cement paste was cured for 1 d and 3 d itsshrinkagewas decreased by 220 and 221 based on controlsample respectively

Taken together with the 120590119862120590

119865and the shrinkage of

cement paste the WPFs dosage of 02 by mass of cementis optimal in either water cement ratio which improved thetoughness and antishrinkage of cement paste However it iseasy to see that the lower the water cement ratio the betterthe antishrinkage capability of the WPFs in cement paste

322 The Effects of Fiber Adding Ways on the Self-ShrinkageTheWPFs dosage of 02 by mass of cement was mixed withcements using wet mixing and dry mixing respectively Thelinear shrinkage strain is shown in Figure 3 The WPFs weremixed with cement using dry mixing way which increasedthe shrinkage of cement paste However using wet mixingthe WPFs decreased the shrinkage of cement paste This

5 10 15 20 25 30 35 40 45 50 6555 60 70

a CHb AFt

c C2Sd C3S

A3 (03 WPFs)

A2 (02 WPFs)

A0

a

a

a

a a ab b b

cc

d

d

2120579 (∘)

Figure 4 XRD patterns of cement pastes at a water cement ratio of025

illustrates that theWPFs adding way of wetmixing was betterthan that of dry mixing even with the same content of WPFs

33 Hydration Characteristic Ca(OH)2

is an importanthydration product of cement-based materials Some proper-ties of cement-basedmaterials such as carbonation resistanceand alkalinity are about the content of Ca(OH)

2 A fast

rate for carbonation caused by low levels of Ca(OH)2leads

to the decrease of pH inducing the corrosion of rebar incement-based materials [29 30] So some levels of Ca(OH)

2

in cement-based materials are necessary but not sufficientcondition for durability

The crystalline phase compositions of cement pastescured for 7 d were identified by XRD and their XRDpatterns are given in Figure 4 In addition to the typicalcharacteristic peaks of C

2S and C

3S the cement hydration

product Ca(OH)2was found in all specimens Although the

diffraction peak intensity was not directly proportional tothe content of crystalline phase some important informationcan be obtained from comparisons of the relative intensity ofCa(OH)

2 When cement paste was cured for 7 days it was

found that the diffraction intensity which was in Ca(OH)2

peak at about 18∘ of cement paste containing 02 WPFswas significantly higher than control sample and cementpaste containing 03 WPFs it showed that more hydrationproducts were formed in cement paste containing 02WPFs

To further confirm the content of Ca(OH)2in the hydra-

tion products the losses of quality of cement pastes curedfor 7 d are analyzed TG-DSC patterns of the standard sampleand the cement paste containing 02WPFs cured for 7 d areshown in Figure 5

From Figure 5 there was an endothermic peak near440∘C in the DSC curve of cement paste which resultedfrom the dehydration of structural water from Ca(OH)

2[31]

According to the loss of quality in the TG curve of pastethe content of Ca(OH)

2in hydration products was calculated


43944∘CMass change minus243

100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)

Figure 5 TG-DSC patterns of cement pastes cured for 7 d at a water cement ratio of 025

Table 6 The content of Ca(OH)2of cement pastes under different

conditions

Project WCAddingdosage()

Curing age(d)

Masschange()

Ca(OH)2

()

A0 025 mdash 7 minus243 999A1 025 01 7 minus248 1020A2 025 02 7 minus269 1106A3 025 03 1 minus224 921A3 025 03 7 minus251 1032A3 025 03 28 minus267 1098A4 025 04 7 minus250 1028B0 03 mdash 7 minus283 1163B2 03 02 7 minus287 1180B5 03 02 7 minus285 1172B5 dry mixing other samples wet mixing

and listed in Table 6 The content of Ca(OH)2in hydration

products continuously increased with the dosage of WPFsWhen the WPFs dosage was 02 by mass of cement thecontent of Ca(OH)

2of cement paste cured for 7 d increased to

1106 from 999 However if the WPFs dosage continuedto increase the content of Ca(OH)

2in hydration products

decreased instead In addition when awater cement ratio was03 the content of Ca(OH)

2in hydration products increased

with the curing age When the cement pastes were identicalin the water cement ratio the WPFs dosage and curing agethe content of Ca(OH)

2in hydration products was different

because of the WPFs adding ways The content of Ca(OH)2

was higher in cement paste which mixed with WPFs usingwet mixing than that of using dry mixing

34 Pore Structure The compactness of cement-based mate-rials is closely related to mechanical property and antishrink-ageThe pore size distribution and pore volume are inevitableto change with the hydration process of cement paste The

WPFs have different effect on pore structure of cement-basedmaterialsThemercury cumulative intrusion curves and theirderivatives are shown in Figure 6

From Figure 6(a) when cured for 7 d the cumulativeintrusion of paste containing WPFs was lower than thatof paste without fibers among them when adding 02WPFs the cumulative pore volume of cement paste waslowest Adding the same dosage of the WPFs the cumulativeintrusion of cement paste decreased with the curing age(Figure 6(b))The cumulative porosity of cement paste curedfor different ages is shown in Table 7 With a water cementratio of 025 and curing for 7 d whatever WPFs dosagethe total porosity of sample decreased In addition thepercentages of the pore which was smaller than 50 nm andthe pore which was greater than 100 nm in the total porosityincreased and decreased respectively Among them the totalporosity of the sample containing 02 WPFs decreased by259 over the control sampleWhen theWC and theWPFsdosage were same the total porosity of sample decreasedwiththe curing age the total porosities of cement pastes curedfor 7 d and 28 d decreased by 442 and 772 over curedfor 1 d respectively With a water cement ratio of 03 thetotal porosity of paste which mixed with the WPFs using wetmixing decreased obviously in comparison with two othersamples

35 Self-Curing Efficiency

351 The Proposing of Self-Curing Efficiency Through theabove analysis the WPFs could enhance toughness and self-shrinkage of cement paste Supporting the cement pastewithout the WPFs as control sample the flexural strengthcompressive strength and linear shrinkage strain were 120590

1198650

120590

1198620 and 120576

0 respectivelyThose of the cement pastewithWPFs

were 120590119865119891 120590119862119891 and 120576

119891 respectively Now drawn up 120578 () as

the self-curing efficiency of WPFs enhanced cement paste inwhich 120578

1was strength efficiency including flexural strength

efficiency 1205781198651

and compressive strength efficiency 1205781198621

and 1205782

was shrinkage efficiency 1205781was the ratio of the reduction of


Table 7 Cumulative porosity of cement paste under different conditions

Code WC Adding dosage () Curing age (days) Cumulative porosity ()lt50 nm 50 nmsim100 nm gt100 nm Total porosity

A0 025 mdash 7 445 866 302 1613A1 025 01 7 434 836 225 1495A2 025 02 7 442 824 088 1354A3 025 03 1 610 899 385 1894A3 025 03 7 370 876 206 1452A3 025 03 28 223 756 143 1122A4 025 04 7 336 929 271 1536B0 03 mdash 7 615 784 522 1921B2 03 02 7 603 622 395 1613B5 03 02 7 634 743 489 1866B5 dry mixing other samples wet mixing

001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days

Pore diameter (120583m)

(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)

A3 (age = 1 day)A3 (age = 7 days)A3 (age = 28 days)

Adding 03 WPFs

001 01 1 10 100


(b)

Figure 6 Cumulative intrusion of cement paste at a water cement ratio of 025

relative strength to reference strength and 1205782was the ratio of

the reduction of linear shrinkage strain to reference shrinkagestrain as shown in the following formula

120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)

Suppose the WPFs are distributed evenly in the cementpaste pore systems of the prewettingWPFs and cement pasteshould be considered as a wholeMoisture also transfers fromthe large pores to tiny pores the pore size of the WPFsis far greater than the porous size of cement paste so themoisture from theWPFsmigrates progressively to the cement

paste The more the moisture the WPFs contain the morethe moisture transfer and the slower the relative humiditydecreases so the capillary stress and shrinkage of cementpaste are smaller and the self-curing efficiency of cementpaste is higher

352 The Model of Self-Curing Efficiency According to theformulas (5) the self-curing efficiencies of cement paste wereobtained as shown in Figure 7 Only 120578 gt 0 the WPFs wereeffective for the improvement of cement paste

When water cement ratio was 025 WPFs could be ableto enhance the self-curing efficiency of cement paste FromFigure 7(a) the flexural strength efficiency of the WPFsenhanced cement paste was best when the dosage of theWPFs was 02 by mass of cement When cured for 7 d and28 d the flexural strength efficiencies of cement paste wereincreased by 19 and 56 respectively This means that theWPF gradually released moisture from itself and promoted


60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)

Figure 7 Self-curing efficiency of cement paste withWPFs at a water cement ratio of 025 (a) Flexural strength efficiency 1205781198651 (b) compressive

strength efficiency 1205781198621 and (c) shrinkage efficiency 120578

2

the hydration of the cement paste However the compressivestrength efficiency 120578

1198621of WPFs enhanced cement paste was

not obvious (Figure 7(b)) The shrinkage efficiencies of thecement paste with 02 WPFs cured for 1 d and 3 d wereimproved 67 and 74 respectively When cement wascured for 7 d the shrinkage efficiency was improved 50 orso (Figure 7(c))

Taking part of samples nonlinear fitting 1205781198651 1205781198621 and 120578

2

using least square method the multiple regression equationabout 120578 and the dosage of WPFs 119909 was obtained as shown inTable 8

According to the fiber spacing theory [32] the fiber isequal to the secondary reinforcement and can be evenlydispersed in concrete which hinders the development ofmicrocrack thus the concrete structure is more compact In

addition it is generally known that some moisture will beconsumed during the hydration process of cement Withoutexternal water in a sealed environment the water that thehydration reaction needs comes mainly from internal waterof paste so a water cement ratio is one of the most importantfactors in the hydration reaction and the shrinkage of cementpaste [33 34] The WPF is a type of cellulose fiber whichplays a fiber bridge role in cement paste and improvesthe interface bonding state Besides the WPFs that ownedporous structures (Figure 1) act as a storage reservoir whichcan absorb and store moisture during mixing with cementleading to the decrease of the effective water cement ratioWith the hydration reaction water consumption causes self-desiccation of capillary in concrete [35] just then the WPFreleases moisture from itself to compensate the capillary and


Table 8 The regression equation of the self-curing efficiency of cement paste

WC Age (d) Self-curing efficiency 120578 Dosage of WPFs 119877

2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1

maintain the pressure in capillary pore at higher levels dur-ing the early-age curing period of cement-based materialsaccelerating the hydration reaction of cementThe self-curingefficiency of WPFs in cement paste is realized based on theabove process The lower the water cement ratio the betterthe self-curing efficiency of cement pastes this is in line withexisting research results [36ndash38]

The dosage and adding ways of the WPFs directly affectthe effective water cement ratio Proper WPFs will releasemore moisture to promote the hydration and more C-S-Hgels grow along theWPFs to fill the space caused by theWPFsdehydration More capillary pores are replaced by gel poreswhich decrease the total porosity of cement paste Howeverwith adding too little WPFs the absorbable and releasablemoisture of WPFs are limited causing the self-curing effectto be ineffective If there are too many WPFs or unevendispersion by drymixing which absorb substantial quantitiesof water and reduce the water cement ratio in an indirectwayWPFs could not unevenly distribute in cement paste themoisture from the WPFs is fail to long-distance transport intime leading to a weakened self-curing efficiency of cementpaste and a relatively low Ca(OH)

2production In addition

the WPFs volume contraction after releasing water causesa plenty of spaces between the WPFs and the cementingmaterial These spaces form some weak spots in stress stateof cement paste which have negative impact on strength andantishrinkage of cement paste

Based on the analysis above under a low water cementratio an optimal dosage and adding ways of the WPFs couldenhance the self-curing efficiency of cement paste In thistext adding 02WPFs to cement paste andwetmixing waysare optimal

4 Conclusions

This study discussed the fact that WPFs reinforced the self-curing behavior of cement paste The important conclusionsare summarized below

Under a low water cement ratio and wet mixing waysthe WPFs can decrease 120590

119862120590

119865and improve the toughness of

cement pasteThe lower the water cement ratio the better thetoughness of cement pasteWhen a water cement ratio is 025

and the dosage of the WPFs is 02 by mass of cement theflexural strengths and the 120590

119862120590

119865of cement pastes cured for

28 d increase by 556 and decrease by 30 respectivelyThe WPFs in cement paste could promote the hydration

process decrease the cumulative pore volume and increasethe self-curing efficiency of cement paste When watercement ratio is low and the WPFs dosage is 02 by massof cement the Ca(OH)

2diffraction intensity of cement paste

cured for 7 d is significantly higher than other samples andincreases to 1106

The WPFs could enhance the self-curing efficiency ofcement paste When a water cement ratio was 025 and thedosage of theWPFs was 02 by mass of cement the flexuralstrength efficiencies of cement paste cured for 7 d and 28 dwere increased by 19 and 56 respectively The shrinkageefficiencies of the cement paste cured for 1 d and 3 d wereimproved 67 and 74 respectively

Competing Interests

The authors declare that they have no competing interests

Acknowledgments

The authors gratefully acknowledge the financial supportsprovided by National Basic Research Program of China (973Program 2011CB013805) National Natural Science Founda-tion of China (51278360 51078269) National Key Project ofScientific and Technical Supporting Programs of China (no2014BAL03B02 no 2012BAJ20B02) the Specialized ResearchFund for theDoctoral Program ofHigher Education of China(no 20130072110047) the science and technology program ofJiangxi province (GJJ150775) and the Fundamental ResearchFunds for the Central Universities

References

[1] T A Hammer ldquoMix design of high strength concrete economicdesign and construction with high strength concreterdquo BriteEuRum Projet 5480 SINTEF Structures and Concrete 1994

[2] K Mitsuui ldquoApplication of 100MPa high strength high fluidityconcrete for prestressed concrete bridge with span-depth ratio


of 40rdquo in Proceedings of the PCIFHWA International Syposiumon High Performance Concrete vol 10 pp 669ndash680 NewOrleans La USA 1997

[3] B Persson ldquoSelf-desiccation and its importance in concretetechnologyrdquoMaterials and Structures vol 30 no 199 pp 293ndash305 1997

[4] Q Yang ldquoInner relative humidity and degree of saturation inhigh-performance concrete stored in water or salt solution for2 yearsrdquo Cement and Concrete Research vol 29 no 1 pp 45ndash531999

[5] A Loukili A Khelidj and P Richard ldquoHydration kineticschange of relative humidity and autogenous shrinkage of ultra-high-strength concreterdquo Cement and Concrete Research vol 29no 4 pp 577ndash584 1999

[6] O M Jensen ldquoThermodynamic limitation of self-desiccationrdquoCement and Concrete Research vol 25 no 1 pp 157ndash164 1995

[7] A Loukili D Chopin A Khelidj and J-Y Le Touzo ldquoNewapproach to determine autogenous shrinkage of mortar atan early age considering temperature historyrdquo Cement andConcrete Research vol 30 no 6 pp 915ndash922 2000

[8] O M Jensen and P F Hansen ldquoInfluence of temperatureon autogenous deformation and relative humidity change inhardening cement pasterdquo Cement and Concrete Research vol29 no 4 pp 567ndash575 1999

[9] M Lopez L F Kahn and K E Kurtis ldquoEffect of internallystored water on creep of high-performance concreterdquo ACIMaterials Journal vol 105 no 3 pp 265ndash273 2008

[10] OM Jensen and P Lura ldquoTechniques andmaterials for internalwater curing of concreterdquo Materials and Structures vol 39 no293 pp 817ndash825 2006

[11] L F Pang S Y Ruan and Y T Cai ldquoEffects of internal curingby super absorbent polymer on shrinkage of concreterdquo KeyEngineering Materials vol 477 pp 200ndash204 2011

[12] G Barluenga ldquoFiber-matrix interaction at early ages of concretewith short fibersrdquo Cement and Concrete Research vol 40 no 5pp 802ndash809 2010

[13] R D Toledo Filho K Ghavami M A Sanjuan and G LEngland ldquoFree restrained and drying shrinkage of cementmortar composites reinforced with vegetable fibresrdquo Cementand Concrete Composites vol 27 no 5 pp 537ndash546 2005

[14] Y Chen JWan X Zhang YMa andYWang ldquoEffect of beatingon recycled properties of unbleached eucalyptus cellulose fiberrdquoCarbohydrate Polymers vol 87 no 1 pp 730ndash736 2012

[15] S Kawashima and S P Shah ldquoEarly-age autogenous and dryingshrinkage behavior of cellulose fiber-reinforced cementitiousmaterialsrdquo Cement and Concrete Composites vol 33 no 2 pp201ndash208 2011

[16] G H D Tonoli M N Belgacem G Siqueira J Bras H Savas-tano Jr and F A Rocco Lahr ldquoProcessing and dimensionalchanges of cement based composites reinforced with surface-treated cellulose fibresrdquo Cement and Concrete Composites vol37 no 1 pp 68ndash75 2013

[17] G Xiuyan J Zhengwu and M Guojin ldquoProperty evaluationof various lignocellulosic fibers from waste paperrdquo Journal ofHarbin Engineering University vol 36 no 2 pp 1ndash5 2015

[18] M A Nassar N A Abdelwahab and N R ElhalawanyldquoContributions of polystyrene to the mechanical properties ofblended mixture of old newspaper and wood pulprdquo Carbohy-drate Polymers vol 76 no 3 pp 417ndash421 2009

[19] R S P Coutts ldquoWastepaper fibres in cement productsrdquo Interna-tional Journal of Cement Composites and Lightweight Concretevol 11 no 3 pp 143ndash147 1989

[20] J Persquorea J Ambroise J Biermann and N Voogt ldquoUse ofthermally converted paper residue as a building materialrdquo inProceedings of the 3rd CANMETACI International Symposiumon Sustainable Development of Cement and Concrete SanFrancisco Calif USA September 2001

[21] B J Mohr H Nanko and K E Kurtis ldquoDurability of kraftpulp fiber-cement composites to wetdry cyclingrdquo Cement andConcrete Composites vol 27 no 4 pp 435ndash448 2005

[22] X Guo Z Jiang H Li and W Li ldquoProduction of recycled cel-lulose fibers from waste paper via ultrasonic wave processingrdquoJournal of Applied Polymer Science vol 132 no 19 pp 6211ndash62182015

[23] Chinese National Standard GBT 17671 Method of TestingCements-Determination of Strength ChineseNational StandardBeijing China 1999

[24] Chinese National Standard JGJT 70 Standard for Test Methodof Basic Properties of Construction Mortar Chinese NationalStandard Beijing China 2009

[25] P Wang Y Peng and X Liu ldquoComparison of methods fordetermination of hydration degree of polymermodified cementpasterdquo Journal of the Chinese Ceramic Society vol 41 no 8 pp1116ndash1123 2013

[26] M Sarigaphuti S P Shah and K D Vinson ldquoShrinkage crack-ing and durability characteristics of cellulose fiber reinforcedconcreterdquo ACI Materials Journal vol 90 no 4 pp 309ndash3181993

[27] P Soroushian and S Ravanbakhsh ldquoControl of plastic shrinkagecracking with specialty cellulose fibersrdquo ACI Materials Journalvol 95 no 4 pp 429ndash435 1998

[28] J R Rapoport and S P Shah ldquoCast-in-place cellulose fiber-reinforced cement paste mortar and concreterdquo ACI MaterialsJournal vol 102 no 5 pp 299ndash306 2005

[29] J Bijen ldquoBenefits of slag and fly ashrdquo Construction and BuildingMaterials vol 10 no 5 pp 309ndash314 1996

[30] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003

[31] C Wang C Yang J Qian M Zhong and S Zhao ldquoBehaviorand mechanism of pozzolanic reaction heat of fly ash andground granulated blastfurnace slag at early agerdquo Journal of theChinese Ceramic Society vol 40 no 7 pp 1050ndash1058 2012

[32] S Wei and J A Mandel ldquoEffects of fiber spacing on interfaciallayersrdquo Journal of the Chinese Ceramic Society vol 17 no 3 pp266ndash271 1989

[33] O M Jensen and P F Hansen ldquoWater-entrained cement-basedmaterialsmdashI Principles and theoretical backgroundrdquo Cementand Concrete Research vol 31 no 4 pp 647ndash654 2001

[34] O M Jensen and P F Hansen ldquoWater-entrained cement-basedmaterials II Experimental observationsrdquo Cement and ConcreteResearch vol 32 no 6 pp 973ndash978 2002

[35] A Ming-zhe Z Jin-quan and Q Wei-zu ldquoAutogenous shrink-age of high performance concreterdquo Journal of Building Materi-als vol 4 no 2 pp 159ndash166 2001

[36] D P Bentz M R Geiker and K K Hansen ldquoShrinkage-reducing admixtures and early-age desiccation in cement pastesand mortarsrdquo Cement and Concrete Research vol 31 no 7 pp1075ndash1085 2001


[37] X Kong and Q Li ldquoInfluence of super absorbent polymeron dimension shrinkage and mechanical properties of cementmortarrdquo Journal of the Chinese Ceramic Society vol 37 no 5 pp855ndash861 2009

[38] H Shu-Guang Z Yu-Fei and W Fa-Zhou ldquoTemperaturecontrolling and monitoring for mass concrete construction ofHuangpu bridgerdquo Journal of Huazhong University of Science andTechnology vol 25 no 1 pp 1ndash4 2008 (Chinese)

Submit your manuscripts athttpwwwhindawicom

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


Nano

materials


Journal ofNanomaterials


25120583m

(a)

25120583m

(b)

Figure 1 SEM surface morphologies of WPFs

Table 1 Chemical component of the waste paper fibers (wt)

Component Cellulose Hemicellulose FillersContent () sim93 sim5 sim2

structure and a nature hydrophilic property [17] Theoreti-cally speaking the WPFs can be used as a substitute for thecellulose fibers and applied in concrete Moreover the WPFsused in concrete do not require the use of the deinking andbleaching processes thereby greatly reducing the emissionsof hazardous substances in the wastewater [18] Previousstudies had shown that cheap WPFs could enhance theconcrete [19] and reduce the dosage of cement [20] themechanical property and the durability of theWPFs concretewere also researched [21] However the use of the WPFs toenhance the shrinkage resistance and self-curing effect ofconcrete has not been yet reported This research aims tocontribute to filling this lack of knowledge

It is generally known that the shrinkage of concrete isinfluenced by many factors except low water ratios in orderto truly reflect the self-shrinkage and self-curing behaviorsof the WPFs reinforced cement-based materials the cementpaste instead of concrete is selected as the matrix which doesnot consider other factorsThe self-shrinkage and self-curingbehaviors of cement paste with the WPFs are researched inthis paper In addition the reasonable addition ways anddosage of WPFs in cement paste at a low water cement ratioare discussed which can provide theoretical basis for actualproduction

2 Experimental

21 Materials Waste paper fibers (WPFs) from newsprintwere pretreated and modified surfaces in our own lab [22]They have an average length of 16mm an average diameterof 24120583m and a specific surface area of 23m2gThe chemicalcontent of theWPFs was listed in Table 1 From the chart thecontent of cellulose was about 93 showing that the WPFsowned good alkali resistanceThe SEM surfacemorphologiesof WPFs were shown in Figure 1 The fiber bundle waslayered along the long end many microfibrils were produced

and exist on the fiber surfaces (Figure 1(a)) and the WPFthat owned porous hollow structure was shown quite clearly(Figure 1(b)) which allows it to absorb and retain water

A Portland cement PII 525 and tap water were used inall mixes a polycarboxylic high-performance water-reducingagent (SD-600P-01) was used to adjust the workability ofcement paste and the fluidities of all the samples werecontrolled at 140 plusmn 10mm The chemical compositions ofclinker were listed in Table 2

22 Mix Design All the mixtures were designed to have afluidity indice of 140plusmn10mm Twomain differences betweenthe mixes were the dosage and the adding ways of the WPFsThe dosages of the WPFs were 01 02 03 and 04by mass of cement respectively Wet mixing and dry mixingwere implemented at a water cement ratio of 03 Amongthem wet mixing was that both the WPFs and the totalquotas of water were weighed firstly and then the fibers weresoaked in the normed water at least 30min until the WPFswere treated to be fully dispersible in water at which pointthis mixture was mixed with cement However dry mixingwas that the preweighed dry WPFs were mixed with cementfirstly and then suitable water was added to compound Themix designs of cement pastes were shown in Table 3

23 Testing Methods To improve the testing accuracy threesame specimens of every curing age were prepared and testedfor each sample as described below

231 Compressive Strength and Flexural Strength Accordingto the Chinese National Standard GBT 17671-1999 [23]cement pastes were casted in 40mm times 40mm times 160mmmolds and vibrated at the time of casting to remove airbubbles The molded pastes were kept at temperature 20 plusmn2

∘C and relative humidity exceeding 95 for 24 h and thenremoved from the molds The demoulded samples weresealed with high density polypropylene film and epoxy resinsealant and then cured in a room with temperature 20∘C andrelative humidity 60 for the set ages The compressive andflexural strengths of all specimens were determined usinga ACE-201 strength test machine Three same specimens ofevery curing age were measured and the arithmetic average



Components SiO2

Al2O3

Fe2O3

CaO MgO SO3

K2O Na

2O Total

Content () 2174 506 356 666 088 081 055 005 9925




WPFs addingway



119862120590

119865) was



0) All specimens



120576

119886119905=

119871

0minus 119871

119905

119871 minus 119871

119889

(1)

where 120576119886119905











119866

119905(CH) = Δ119898

119898

0

times

119872CH119899119872losstimes 100 (2)


2O (3)








119875 =

minus2120590

1015840 cos 120579119903

(4)




119862120590

119865







119862120590

119865is one of the


119865 the better



119862120590

119865of samples





119862120590

119865of cement


119862120590

119865of


119862120590

119865of cement


119862120590

119865of cement




119862120590

119865


16

12

8

4

0

WC = 025

A0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(a)

16

12

8

4

0

WC = 03

B0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(b)




119862120590




119862120590


119862120590








16

12

8

4

0

WC = 03


0 10 20 30 40 50 60 70 80 90

Curing age (d)

Shrin

kage

(Eminus4)








5 10 15 20 25 30 35 40 45 50 6555 60 70

a CHb AFt

c C2Sd C3S

A3 (03 WPFs)

A2 (02 WPFs)

A0

a

a

a

a a ab b b

cc

d

d

2120579 (∘)





2 A fast



2



2S and C










2[31]





100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)



conditions


Curing age(d)

Masschange()

Ca(OH)2

()


















1198650

120590

1198620 and 120576


were 120590119865119891 120590119862119891 and 120576






and 1205782






001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





Components SiO2

Al2O3

Fe2O3

CaO MgO SO3

K2O Na

2O Total

Content () 2174 506 356 666 088 081 055 005 9925




WPFs addingway



119862120590

119865) was



0) All specimens



120576

119886119905=

119871

0minus 119871

119905

119871 minus 119871

119889

(1)

where 120576119886119905











119866

119905(CH) = Δ119898

119898

0

times

119872CH119899119872losstimes 100 (2)


2O (3)








119875 =

minus2120590

1015840 cos 120579119903

(4)




119862120590

119865







119862120590

119865is one of the


119865 the better



119862120590

119865of samples





119862120590

119865of cement


119862120590

119865of


119862120590

119865of cement


119862120590

119865of cement




119862120590

119865


16

12

8

4

0

WC = 025

A0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(a)

16

12

8

4

0

WC = 03

B0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(b)




119862120590




119862120590


119862120590








16

12

8

4

0

WC = 03


0 10 20 30 40 50 60 70 80 90

Curing age (d)

Shrin

kage

(Eminus4)








5 10 15 20 25 30 35 40 45 50 6555 60 70

a CHb AFt

c C2Sd C3S

A3 (03 WPFs)

A2 (02 WPFs)

A0

a

a

a

a a ab b b

cc

d

d

2120579 (∘)





2 A fast



2



2S and C










2[31]





100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)



conditions


Curing age(d)

Masschange()

Ca(OH)2

()


















1198650

120590

1198620 and 120576


were 120590119865119891 120590119862119891 and 120576






and 1205782






001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






119862120590

119865







119862120590

119865is one of the


119865 the better



119862120590

119865of samples





119862120590

119865of cement


119862120590

119865of


119862120590

119865of cement


119862120590

119865of cement




119862120590

119865


16

12

8

4

0

WC = 025

A0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(a)

16

12

8

4

0

WC = 03

B0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(b)




119862120590




119862120590


119862120590








16

12

8

4

0

WC = 03


0 10 20 30 40 50 60 70 80 90

Curing age (d)

Shrin

kage

(Eminus4)








5 10 15 20 25 30 35 40 45 50 6555 60 70

a CHb AFt

c C2Sd C3S

A3 (03 WPFs)

A2 (02 WPFs)

A0

a

a

a

a a ab b b

cc

d

d

2120579 (∘)





2 A fast



2



2S and C










2[31]





100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)



conditions


Curing age(d)

Masschange()

Ca(OH)2

()


















1198650

120590

1198620 and 120576


were 120590119865119891 120590119862119891 and 120576






and 1205782






001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






119862120590

119865


16

12

8

4

0

WC = 025

A0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(a)

16

12

8

4

0

WC = 03

B0

0 10 20 30 40 50 60 70 80 90

Curing age (d)



Shrin

kage

(Eminus4)

(b)




119862120590




119862120590


119862120590








16

12

8

4

0

WC = 03


0 10 20 30 40 50 60 70 80 90

Curing age (d)

Shrin

kage

(Eminus4)








5 10 15 20 25 30 35 40 45 50 6555 60 70

a CHb AFt

c C2Sd C3S

A3 (03 WPFs)

A2 (02 WPFs)

A0

a

a

a

a a ab b b

cc

d

d

2120579 (∘)





2 A fast



2



2S and C










2[31]





100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)



conditions


Curing age(d)

Masschange()

Ca(OH)2

()


















1198650

120590

1198620 and 120576


were 120590119865119891 120590119862119891 and 120576






and 1205782






001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




16

12

8

4

0

WC = 03


0 10 20 30 40 50 60 70 80 90

Curing age (d)

Shrin

kage

(Eminus4)








5 10 15 20 25 30 35 40 45 50 6555 60 70

a CHb AFt

c C2Sd C3S

A3 (03 WPFs)

A2 (02 WPFs)

A0

a

a

a

a a ab b b

cc

d

d

2120579 (∘)





2 A fast



2



2S and C










2[31]





100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)



conditions


Curing age(d)

Masschange()

Ca(OH)2

()


















1198650

120590

1198620 and 120576


were 120590119865119891 120590119862119891 and 120576






and 1205782






001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00A0

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(a)

A2 (02 WPFs)


100

95

90

85

80

TG (

)

100 200 300 400 500 600 700 800

Temperature (∘C)

DSC

(Wg

)

00

minus02

minus04

minus06

minus08

minus10

minus12

minus14

minus16

(b)



conditions


Curing age(d)

Masschange()

Ca(OH)2

()


















1198650

120590

1198620 and 120576


were 120590119865119891 120590119862119891 and 120576






and 1205782






001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







001 01 1 10 100

A0

A2 (02 WPFs)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Age = 7 days


(a)

010

008

006

004

002

000

Cum

ulat

ive i

ntru

sion

(mL

g)


Adding 03 WPFs

001 01 1 10 100


(b)




120578

1198651=

120590

119865119891minus 120590

1198650

120590

1198650

times 100

120578

1198621=

120590

119862119891minus 120590

1198620

120590

1198620

times 100

120578

2= minus

120576

119891minus 120576

0

120576

0

times 100

(5)






60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




60

40

20

0

minus20

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

Stre

ngth

effici

ency

120578F1

()

(a)

WC = 025



0 10 20 30 40 50 60 70 80 90

Curing age (d)

15

10

5

0

minus5

minus10

minus15

Stre

ngth

effici

ency

120578C

1(

)

(b)

0



0 10 20 30 40 50 60 70 80 90

Curing age (d)

100

80

60

40

20

Shrin

kage

effici

ency

1205782

()

WC = 025

(c)



2





2







2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






2

025 1120578

1198651= minus37857119909

2+ 10043119909 minus 03714 0 le 119909 le 04 09519

120578

1198621= minus150119909

2+ 55119909 minus 02 0 le 119909 le 04 09239

120578

2= 59167119909

3minus 39714119909

2+ 8644119909 minus 11286 0 le 119909 le 04 09795

025 7

120578

1198651= 19167119909

3+ 62143119909

2+ 30595119909 minus 06714 0 le 119909 le 04 0937

120578

1198621= minus83333119909

3+ 33571119909

2minus 10952119909 minus 00857 0 le 119909 le 04 09899

120578

2= 245119909 minus 08333 119909 lt 02 09965

120578

2= 3650119909

2minus 2245119909 + 352 02 le 119909 le 04 1

025 28

120578

1198651= minus98571119909

2+ 42429119909 minus 17143 02 le 119909 le 04 08758

120578

1198621= minus18571119909

2+ 42286119909 + 00857 02 le 119909 le 04 09888

120578

2= 240119909 minus 16667 119909 lt 02 09857

120578

2= 3250119909

2minus 2035119909 + 325 02 le 119909 le 04 1






4 Conclusions



119862120590




119862120590







Competing Interests


Acknowledgments


References

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials

















































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials













CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



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