research article synthesis of a cementitious material nanocement using bottom...

Research ArticleSynthesis of a Cementitious Material Nanocement UsingBottom-Up Nanotechnology Concept An AlternativeApproach to Avoid CO2 Emission during Production of Cement

Byung Wan Jo Sumit Chakraborty and Kwang Won Yoon

Department of Civil and Environmental Engineering Hanyang University Seoul 133791 Republic of Korea

Correspondence should be addressed to Byung Wan Jo joyconhanmailnet

Received 2 May 2014 Revised 18 July 2014 Accepted 26 July 2014 Published 11 September 2014

Academic Editor Gaurav Mago

Copyright copy 2014 Byung Wan Jo et al This 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

Theworldrsquos increasing need is to develop smart and sustainable constructionmaterial whichwill generateminimal climate changinggas during their production The bottom-up nanotechnology has established itself as a promising alternative technique for theproduction of the cementitious material The present investigation deals with the chemical synthesis of cementitious materialusing nanosilica sodium aluminate sodium hydroxide and calcium nitrate as reacting phases The characteristic properties ofthe chemically synthesized nanocement were verified by the chemical composition analysis setting time measurement particlesize distribution fineness analysis and SEM and XRD analyses Finally the performance of the nanocement was ensured bythe fabrication and characterization of the nanocement based mortar Comparing the results with the commercially availablecement product it is demonstrated that the chemically synthesized nanocement not only shows better physical and mechanicalperformance but also brings several encouraging impacts to the society including the reduction of CO

2emission and the

development of sustainable construction material A plausible reaction scheme has been proposed to explain the synthesis andthe overall performances of the nanocement

1 Introduction

The modern civil infrastructures undeniably depend on thecement based material More than ever before the worldrsquosincreasing need for the development of the new infras-tructure demands the construction of efficient sustainableand durable building materials generating minimal climatechanging gas during their production Based on the world-wide screening report it is apparent that the Portland cementis the most common and widely used construction materialand its current production is estimated to be sim2 billion tonsper year Reviewing the literature it is anticipated that theabundant resource of the oxide composition (SiO

2 CaO

Al2O3 and Fe

2O3) present in the cement is the earthrsquos crust

(sim90)The earthrsquos crust is used as a primary rawmaterial forthe production of cement [1] Additionally it is reported thatduring the production of the 1 ton of cement sim700 kgndash800 kgof CO

2is liberated [2] The CO

2is the primary component

of the greenhouse gases and causes global warming and

environmental pollution Therefore an immediate practicalplan is required to reduce the CO

2emission Accordingly it

is essential to produce cement using an alternative pathwayother than clinkering method In this regard the nan-otechnology would be the encouraging practice Althoughthe properties of concrete have been well established at amacrostructural level however the understanding of theproperties of micronanoscale level is yet to be investigated[3ndash5] Recently due to the availability of the modern charac-terization techniques it is possible to characterize the cementconcrete at nanoscale level [6 7] Thus it is ascertainedthat the nanotechnology is the unique scheme of scienceable to change our vision expectations and amenities tocontrol the material world The technological revolutiontowards nanoscale level has propensity to improve the qualityof the products and services Therefore the encouragingimpacts of the nanotechnology will definitely affect the fieldof building and construction materials Hence in the presentscenario the researchers have beenmotivated to develop high

Hindawi Publishing CorporationJournal of NanomaterialsVolume 2014 Article ID 409380 12 pageshttpdxdoiorg1011552014409380

2 Journal of Nanomaterials

Table 1 Effect of different nanomaterials on the performances of the cement composite

Primary material Additivesprocedure Particle Size Effectperformance Reference

Portland cement

Nanosize ingredients suchas alumina silica particlesand carbon nanotubes wereadded

lt500 nmNanocement can create new materialsdevices and systems at the molecularnano- and microlevel

[3]

Portland cement

Nano-SiO2 nano-TiO2nano-Al2O3 nano-Fe2O3and nanotubenanofibreswere added

sim20 nm and 100 nmCan produce concrete with superiormechanical properties as well asimproved durability

[4]

Portland cementSingle wall and multiwallcarbon nanotubes wereadded

mdashCement materials showed superiormechanical electrical and thermalproperties

[8]

Ordinary Portlandcement

Spherical nanoparticlenano-SiO2 nano-Fe2O3and multiwall carbonnanotubes were added

1ndash100 nmSignificant improvement incompressive strength as well as Youngrsquosmodulus and hardness of the concrete

[9]

Portland cement Spherical nano-Fe2O3 andnano-SiO2 were added

15 nm Mortar showed higher compressivestrength as well as flexural strength [16]

Nano-SiO2nano-NaAlO2 andnano-Ca(NO3)2

Using the hydrothermalmethod a new type ofcement material isproduced

167 nm

A new cementitious material isproduced using pozzolanic materialinfused with hydrated alumina whichavoids CO2 emission able to controlmechanical performance of the mortar

Present work

performance smart and sustainable construction materialsby the tuning of the existing processes together in combi-nation with the nanotechnology [4 8 9] At the outset itwas anticipated that the mechanical performances and thedurability of concrete could be improved by reducing theoverall porosity of the concrete [4] It can only be possibleif the capillary pores of the cement paste are reduced or thediffusion of the pore solution is restricted by the assimilationof some additives to a similar range of capillary pore sizes[4 9 10] Thus the bottom-up nanoengineered constructionprocess is used to reduce nanocapillary pores of cementpaste [4 8] Accordingly the process is a very successfuland promising one which encompasses the structure at thenanoscale level to develop multifunctional cement compos-ites with superior mechanical performance and durability[4 9 10] Perhaps the nanoengineered construction processis mainly based on the incorporation of nanoscale materialssuch as spherical nanomaterial (namely nano-SiO

2 nano-

TiO2 nano-Al

2O3 nano-Fe

2O3 etc) nanofiber (namely

carbon nanotube (CNT) and carbon nanofibers (CNF)) andnanoclay into cement system during mixing of cement andaggregate to produce concrete [4 7ndash10] In view of thatthe nanoengineered process potentially brings a range ofnovel properties such as high ductility self-healing self-crackcontrolling ability low electrical resistivity and self-sensingcapabilities [11] In addition to the nanoparticle incorporationin concrete system modification of the aggregate surfaceusing nanoporous thin film to produce nanoengineeredconstruction material is also reported elsewhere in orderto improve the interfacial transition zone (ITZ) in betweenaggregate and cement paste [12ndash16] Moreover in a previousresearch we have demonstrated that the chemical synthesis of

a cementitious material using noncarbon based raw material[17] Table 1 summarizes the effect of different nanomaterialsand procedures on the performances of the nanoengineeredconcrete

Reviewing the literature it is prophesied that the incorpo-ration of the external nanomaterial into cement system hassucceeded to improve physical characteristics mechanicalproperties and novel performances of cementitious materi-als however the process is unable to reduce CO

2emission

during the production of cement From the review of theexisting literature it is apparent that the production ofthe cementitious material without emitting CO

2has not

been studied yet In a previous study [17] we have demon-strated the chemical synthesis of the alternative cementitiousmaterial however the structure property relation was notevaluated In order to minimize the emission of CO

2and

to produce alternative cementitious material we have triedto establish an innovative alternative pathway In this inves-tigation we have studied the chemical synthesis structureproperty correlation and application of the cementitiousmaterial The chemical synthesis of nanocement is demon-strated to be very effective not only to enhance the physicaland mechanical performances of cement based material butalso to control the CO

2emission during its production

2 Experimental Program

In this investigation we have set a systematic experimentalprogram to synthesize an alternative cementitious material(nanocement) using the hydrothermal method For the syn-thesis of the nanocement using the hydrothermal method

Journal of Nanomaterials 3

initially the raw materials were selected carefully whichdid not emit CO

2in any step of the synthesis Finally the

nanocement based mortar was fabricated and characterized

21 Materials The alternative cementitious material (nano-cement) was synthesized using 999 pure nanosilica pur-chased from Asia Cement Manufacturing Co Ltd DaeguKorea The particle size specific gravity and surface areaof the used nanosilica are reported to be 40 nm 013 and65m2g respectively

The other chemicals such as sodium aluminate sodiumhydroxide pellet purified (98) triethanol amine (TEA) andcalciumnitrate used for the synthesis of the nanocementwerepurchased from Sigma Aldrich Korea

Nanocement mortar was fabricated using the fine aggre-gate of the average particle size lt06mmThe specific gravityfineness modulus and water absorption of the used fineaggregate are estimated to be 263 248 and 01 respec-tively

22 Synthesis of Nanocement The synthesis of the alternativecementitious material (nanocement) using the hydrothermalprocess was performed subsequent to the preparation of thesilica and alumina source materials At the first step of thesynthesis 67 g of sodium hydroxide was dissolved in 100mLof deionizedwater in a Pyrex flux Afterwards 38 g of sodiumaluminate was added gently in the flux The flux was thenplaced on a heating mantle for 10ndash15min maintaining thetemperature of the mantle at 90∘C to dissolve the materialin the solution After completion of this process the fluxwas then allowed to cool and left to attain the ambienttemperatureThereafter 164 g of triethanol amine was addeddropwise as an emulsifier to prevent the precipitation ofthe prepared alumina source Subsequently the preparedalumina source was then allowed to ripen for 24 h to producea soft gel material Additionally in the second step of thesynthesis exactly 125 g of the pure nanosilica was addedto 100mL of deionized water in an another pyrex fluxThe flux was then placed on a magnetic stirrer to preparea thick gel of silica source material Thereafter the thickgel of the silica source material was allowed to ripen for24 h at ambient condition Subsequently the prepared sourcematerials of the silica and alumina weremixed together usinga turbine mixture followed by 3 h sonication to disperse thecomponents homogeneously Consequently the compoundsynthesized in this process was then allowed to dry in ovenat 105∘C for 15 days The crystallized product thus obtainedwas then washed with distilled water and filtered off usinga membrane filter Finally the residue was allowed to dry inoven at 105∘C for 6 h followed by grinding in a mortar pestleto obtain a powder material

Typically the Portland cement contains three principalingredients such as SiO

2 Al2O3 and CaO The material

synthesized in this investigation carried adequate amount ofSiO2and Al

2O3 however it did not contain CaO In this

context the powder material was treated with the calciumnitrate (Ca(NO

3)2) solution to increase the CaO content

Finally the sample was allowed to centrifuge and filtered

off followed by oven drying at 105∘C for 24 h The productthus obtained was then ground to acquire a powder of thealternative cementitious material (nanocement)

23 Fabrication of Nanocement Mortar Cement mortar wasfabricated using chemically synthesized nanocement fineaggregate alkali activator and water In this investigationthe 50 sodium hydroxide solution was used as an alkaliactivator for the fabrication of the nanocement based mor-tar The samples were prepared varying the water contentalkali activator content and fine aggregate content In aparticular batch mixing of the nanocement based mortar100 g of nanocement was mixed with fine aggregate (varyingamounts sim200 gndash400 g) followed by the mixing with analkali activator (varying amounts sim30mLndash95mL) and water(varying amounts sim20mLndash50mL) Additionally a controlcement mortar was fabricated using 100 g of the Portlandcement 314 g of fine aggregate and 50mL of water Table 2represents the formulation code and the weight of differentcomponents for the fabrication of the control mortar aswell as nanocement mortar Finally the prepared mortarsamples were then cast immediately in the cubic mold ofthe dimension 50 times 50 times 50mm3 and allowed to set for24 h After complete setting the cement mortar samples werethen allowed to water cure for 3 7 14 and 28 days Aftercompletion of the desired curing time the mortar sampleswere removed from the curing chamber and tested Theresults were compared with the control sample As repre-sented in Table 2 the formulation code MN-W indicates thatthe nanocement mortar is fabricated using varying amountsof water content Similarly the formulation codeMN-A refersto the nanocement mortar fabricated using varying amountsof alkali activator content and the code MN-F implies thatthe nanocement mortar is fabricated using varying amountsof fine aggregate content Additionally the formulation codeCCM refers to the control cement mortar

24 Characterization

241 Physical Properties of Cement The specific gravity andfineness of the chemically synthesized nanocement wereanalyzed in accordance with the Korean standard KS L 5110[18] Particle size distribution of the cementitious materialsynthesized in this investigation was performed using LA-950 Laser particle size analyzer instrument purchased fromHoriba Ltd Kyoto Japan For the analysis of the cementsamples initially the samples were dried in oven at 105∘C toremove themoisture During the particle size analysis exactly1 g of the dry samples was fed into the PowderJet Dry Feederof the LA-950 Laser particle size analyzer Furthermoresamples were analyzed based on the Mie scattering theoryIn this instrument two light sources are used to analyzethe particle size namely 5mW 650 nm red laser diode and3mW 405 nm blue LED In the measurement array thehigh quality photodiodes are used to detect the scatteredlight over a wide range of angles The results obtained fromthese experiments were comparedwith the ordinary Portlandcement and Portland pozzolana cement


Table 2 Formulation code and mix proportions of components for the fabrication of control as well as nanocement mortar

Type of variability Formulation code ComponentsCement (g) Water (mL) 50 NaOH solution (mL) Fine aggregate (g)

Control CCM 100a 50 mdash 314

Water variation

MN-W1 100b 12 50 314MN-W2 100b 16 50 314MN-W3 100b 20 50 314MN-W4 100b 24 50 314MN-W5 100b 29 50 314MN-W6 100b 40 50 314MN-W7 100b 50 50 314

Alkali activator variation

MN-A1 100b 20 30 314MN-A2 100b 20 40 314MN-A3 100b 20 50 314MN-A4 100b 20 60 314MN-A5 100b 20 70 314MN-A6 100b 20 80 314MN-A7 100b 20 90 314MN-A8 100b 20 95 314

Course aggregate variation

MN-F1 100b 20 50 200MN-F2 100b 20 50 245MN-F3 100b 20 50 300MN-F4 100b 20 50 400

aOrdinary Portland cement bChemically synthesized nanocement

242 Chemical Composition Analysis Chemical compo-sitions of the cementitious material synthesized in thisinvestigation were analyzed using Rigaku NEX QC energydispersive X-ray fluorescence (EDXRF) analyzer AppliedRigaku Technologies Inc Austin USA Before the analysiscement samples were dried in oven at 105∘C and cooledto room temperature by storing the samples in a vacuumdesiccator The cement samples were analyzed packing thesamples on a 40mm rectangular hollow area of the sampleholder Thereafter the analysis was performed in heliumenvironment In this instrument a 50KvX-ray generator tubeis used to generate the X-ray for the analysis of the sampleand a high performance SDD semiconductor based recorderis used to detect the signal The result obtained from thisexperiment was further clarified by the energy dispersive X-ray spectroscopy (EDX)

243 FE-SEM Analysis Field emission scanning electronmicroscopic (FE-SEM) images of the synthesized nanoce-ment and commercially available Portland cement wererecorded using JEOL JSM-6700F JEOL USA Inc USA Inthis microscope the electrons are emitted from a bent tung-sten filament (withstand high temperature without melting)The emitted electrons are accelerated by the application ofhigh voltage (maximum 30 kV) which in turn leads to strikeon the surface of the sample consequently the electrons areliberated from the outer shell of the sample The liberatedelectrons are termed as secondary electron focused by elec-tromagnetic lenses with a maximum magnification capacity

1000000xThe scanning of the electron beam over the samplesurface is controlled by deflecting the electron beam usinga scanning coil During this investigation a very thin goldwas sputter coated on the surface of the moisture free driedsamples to avoid charging Thereafter samples were placedon the SEM stub and allowed to analyzeThe digital scanningelectron micrographs were recorded in 10ndash20 kV acceleratedvoltage and 15 kx magnification

244 Setting Time Measurement Setting times (initialand final) of the newly synthesized cementitious material(nanocement) as well as Portland cement were estimatedin accordance with the standard KS L 5108 [19] This is astandard method to predict the setting time of the hydrauliccement using Vicat apparatus

245 X-Ray Diffraction Analysis The structural character-istics of the chemically synthesized cementitious materialwere examined using an X-ray diffractometer (Ultima IIIRigaku Inc Japan) The CuK120572 radiation (40 kV 40mA)and Ni filter were used to produce the X-ray The X-raydiffractograms of the samples were recorded in the 2120579 range5∘ndash60∘ maintaining a scan speed of 1∘minminus1 with a stepdifference of 00210158401015840 In this investigation X-ray diffraction ofthe oven-dried samples was recorded by packing the samplesin a rectangular hollow area of the glass made sample holderIn this instrument a tungsten (W) filament is used as cathodeand a desired targetmetal for example Cu is used as an anode


Table 3 Physical properties of the synthesized nanocement as well as commercially available different types of cement

Properties Type of cementOrdinary Portland cement Blast furnace slag cement Fly ash based cement Synthesized nanocement

Particle size (120583m) 10sim30 10sim30 20sim30 0167Specific gravity 315 303 294 211Fineness (cm2g) sim2800 sim2600 sim2500 3582400

Table 4 Oxide composition () present in nanocement as well as ordinary Portland cement

Type of cement Chemical composition ()CaO Na2O SiO2 Al2O3 MgO Fe2O3 SO3 Loss of Ig

Ordinary Portland cement 6433 mdash 2036 577 205 284 251 20Chemically synthesized nanocement 371 531 428 219 041 237 mdash 032

to produce themonochromatic X-ray beamof thewavelength15 A

246 Compressive Strength Measurement The compressivestrength of the nanocement based mortar as well as controlcement mortar of the dimension 50 times 50 times 50mm3 wasmeasured using a universal testing machine with a loadingrate 006MPamin in accordance with the Korean standardKS F 2405 [20]

3 Results and Discussion

31 Physical Properties Table 3 represents the physical prop-erties such as particle size specific gravity and fineness ofthe chemically synthesized alternative cementitious material(nanocement) The results are compared with the commer-cially available Portland cement and Portland pozzolanacement As observed from the table particle size of thechemically synthesized cement is sim0168 120583m (168 nm) whichis significantly smaller as compared to that of the ordinaryPortland and Portland pozzolana cement The particle sizedistribution pattern of the newly synthesized cement isrepresented in Figure 1 From the figure it is observed that theparticle size of the cement synthesized in this investigationbelongs to nanometer scale Therefore it is considered thatthe process used in this investigation is able to synthesizean alternative cementitious material of the nanoscale particlesize From Table 3 it is also visualized that the finenessof the synthesized cementitious material is quite higher ascompared to that of the commercially available ordinaryPortland and Portland pozzolana cement It is reportedelsewhere that the smaller particle size leads to increase inthe fineness of the cement [21] As evidenced from Table 3it can be considered that the higher fineness of the cementleads to increase in the surface area which in turn increasesthe volume of the cement and consequently minimizes thespecific gravity

32 Chemical Analysis Subsequent to the analysis of thephysical performances the chemical compositions werealso analyzed to assess the basic chemical characteristics

001 01 10

4

8

12

16

20

Chan

nel (

)

Channel ()

Pass

()

0

20

40

60

80

100

Pass ()

Particle size (120583m)

Figure 1 Particle size distribution pattern of the chemically synthe-sized nanocement

of the synthesized cementitious material Typically cementcontains dicalcium silicate (C

2S) tricalcium silicate (C

3S)

tricalcium aluminate (C3A) and tetracalcium aluminoferrite

(C4AF) phases [22 23] The mentioned phases are pre-

dominantly composed of oxide components of the calciumsilicon aluminium and iron Table 4 represents the oxidecompositions of the ordinary Portland cement as well aschemically synthesized nanocement From the table it isenvisaged that the chemically synthesizednanocement aswellas ordinary Portland cement contains identical oxide phaseshowever the quantities of the chemical constituents of thesetwo cements are not identical This is due to the difference insource material used for the synthesis of the nanocement andthe production of ordinary Portland cement Additionallyit is visualized from Table 4 that higher amounts of silicaalumina and sodium oxide are carried by the chemicallysynthesized cementitious material as compared to that ofthe ordinary Portland cementThis phenomenon can furtherbe supported by EDX analysis Accordingly it is reportedelsewhere that the hydration of the Portland cement usually


(a) (b)

Figure 2 FE-SEMmicrographs of the (a) ordinary Portland cement and (b) chemically synthesized nanocement

Table 5 Identification of the chemical constituents of the nanoce-ment by EDX

Type of the cement Chemical constituents ()Ca Na Al Si O

Nanocement 1009 200 2505 3262 3024

produces calcium silicate hydrate and calcium hydroxidepredominantly [22] whilst hydration of the chemically syn-thesized cementitious material may produce calcium sodiumalumino silicate hydrate in addition with calcium silicatehydrate and calcium hydroxideTherefore from the chemicalcomposition analysis it is acquainted that the method usedin this investigation is the unique scheme to synthesize analternative cementitious material of nanoscale particle size(nanocement) without clinkering at high temperature

33 FE-SEM and EDX Analysis Figures 2(a) and 2(b) rep-resent the field emission scanning electron micrographs ofthe Portland cement and the chemically synthesized cementrespectively From Figure 2(a) it is clearly visualized that theparticle size of the ordinary Portland cement is belongingin microscale level whilst the particle size of the chemi-cally synthesized cement is belonging to the nanoscale level(Figure 2(b)) From the figures it is also perceived that theordinary Portland cement particles have structural inequalitywhereas the particles of the chemically synthesized cemen-titious material have quite structural similarity Thereforefrom the FE-SEM analysis of the cement particles it isappraised that the process used in this investigation is ableto synthesize nanoscale cement particle During the FE-SEManalysis EDX was also performed to clarify the chemicalconstituents present in the synthesized cementitious material(nanocement) Figure 3 represents the EDX analysis of thechemically synthesized cementitious material (nanocement)Table 5 represents the summary of Figure 3 From the tableit is visualized that the chemically synthesized cementitiousmaterial as well as ordinary Portland cement contains identi-cal chemical constituents

34 Setting Time Setting time of the cement is one of theimportant characteristics and provides the information of

O

Ca Na

Al

Si

Ca

0 1 2 3 4 5 6 7 8 9 10

(keV)

3

Figure 3 EDX analysis of chemically synthesized nanocement

how long concrete maintains its liquidity It is an output ofthe hydration reaction occurring among the chemical phasesof the cement in the presence of water as reacting mediumIn this investigation setting of the chemically synthesizednanocement is occurring due to the condensation reactionof the reacting phases in the presence of an alkali activator(50 NaOH solution) In the present investigation thecementitious material was synthesized from the pozzolanicmaterial (nanosilica) infused with hydrated alumina usingthe hydrothermal method Therefore the occurrence of thehydration reaction among the chemical phases is difficultin the presence of the water only Hence the use of analkali activator in aqueous solutionmay achieve driving forceto allow the hydration reaction and leads to setting of thecementitious material Figure 4 represents the variation ofsetting times (initial and final) of the chemically synthesizednanocement with increase in curing temperature From thefigure it is visualized that the initial and final setting timesof the nanocement decrease significantly with increase incuring temperature As envisaged from Figure 4 the initialand final setting times of the nanocement were 230minand 540min respectively at 30∘C which are considerablyreduced to 22min and 27min respectively at the curingtemperature 60∘C Beyond this temperature the decrement


20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)

Initial setting time of nanocementFinal setting time of nanocementInitial setting time of Portland cementFinal setting time of Portland cement

Temperature (∘C)

Figure 4 Initial and final setting times of the ordinary Portlandcement at 30∘C and the variation of the initial and final setting timesof the chemically synthesized nanocement with increase in curingtemperature

of the setting times slows down and becomes almost constantat 90∘C Hence it is considered that the alkali activatedcondensation reaction proceeds very fast at the temperaturerange 60∘Cndash90∘C as compared to that of the normal tem-perature (30∘C) From Figure 4 the initial and final settingtimes of the ordinary Portland cement are estimated to be 210and 300min respectively at 30∘C It is reported in Koreanstandard KS L 5201 [24] that a standard cement should havethe initial setting time more than 60min and final settingtime less than 10 h at ambient condition Accordingly inthis investigation the ordinary Portland cement as well asthe chemically synthesized nanocement tracks the Koreanstandard Therefore from the setting time analysis it isconsidered that the cementitious material synthesized usingthe hydrothermal method can be used for the normal con-struction as well as rapid construction purpose

35 Compressive Strength Subsequent to the analysis of thephysical chemical and fresh properties of the synthesizedmaterial the mechanical performance of the chemicallysynthesized nanocement has been elucidated measuring thecompressive strength of the nanocement based mortar Inthis investigation different mortar samples were fabricatedvarying the water content alkali activator content and fineaggregate content In this investigation the compressivestrength of the nanocement mortar is compared with thecontrol cement mortar fabricated using ordinary Portlandcement Comparing the compressive strength of the nanoce-mentmortar with the ordinary Portland cement it is assessedthat the nanocement based mortar performs similarly orbetter as compared to that of the ordinary Portland cement

0

10

20

30

40

Sample codes for water content variation

Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM

Figure 5 Compressive strength of control mortar and variation ofthe compressive strength of nanocement basedmortar with increasein water content

0

10

20

30

40

50

60

Sample codes for alkali activator content variation

Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8

Figure 6 Compressive strength of control mortar and variation ofthe compressive strength of nanocement basedmortar with increasein alkali activator content

Figure 5 represents the variation of compressive strength ofnanocement mortar (cured for 7 days) with increase in watercontent (weight with respect to weight of nanocement) Asvisualized from the figure compressive strength of themortarincreases initially up to 20water content followed by reduc-ing with further increases in water content It indicates thatmaximum compressive strength of the nanocement basedmortar is achieved at 20 water content Hence it is consid-ered that the lower water content shows better performancein compressive strength of the nanocement based mortarSimilarly Figures 6 and 7 represent the variation of thecompressive strength with increase in alkali activator content


0

10

20

30

40

50

Sample codes for fine aggregate variation

Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4

Figure 7 Compressive strength of control mortar and variation ofthe compressive strength of nanocement basedmortar with increasein fine aggregate content

and fine aggregate content respectively From Figure 6 it isrevealed that the compressive strength of the nanocementmortar increases gradually with increase in alkali activatorcontent This is may be due to the occurrence of the fasterrate condensation reaction among the chemical phases ofnanocement in the presence of a higher alkali activator andlower water content From Figure 7 it is observed that thecompressive strength of the nanocement mortar increasesgradually with increase in fine aggregate content up to 300wt followed by decreasing with further increase in aggregatecontent Therefore analyzing the compressive strength it isappraised that themortar fabricated using nanocement showssuperior mechanical performance in the presence of higheralkali activator content lower water content and optimizedfine aggregate content (sim300 weight )

As it seems from the setting time analysis the setting of thenanocement occurs very fast at high temperature (sim90∘C)Keeping the effect in mind a nanocement based mortar wasprepared using 100 g cement 95 g of alkali activator (50NaOH solution) and 314 g of fine aggregate and allowedto cure in two different temperatures to evaluate the effectof high temperature on the mechanical performance of themortar Analyzing the result the compressive strengths after3 days and 7 days curing of the mortar fabricated usingthe above-mentioned mix design and cured at 90∘C areestimated to be sim626MPa and 65MPa respectively whilstthe compressive strengths after 3 days and 7 days curing ofthe mortar fabricated using the same mix design and curedat normal temperature (30∘C) are estimated to be sim56MPaand 615MPa respectively The rapid development of thecompressive strength at high temperature confirms the fastoccurrence of condensation reaction of the chemical phasespresent in nanocement

In addition to the effect of curing temperature the effectof curing time on the compressive strength of nanocement

0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)

Experimental data pointsFitted curve

R2 = 0989

y = 6306526 minus 1828976exp(minus033782x)

Figure 8 Variation of the compressive strength of the nanocementbased mortar as the function of curing time

based mortar has also been investigated Figure 8 representsthe variation of the compressive strength of the nanoce-ment based mortar (fabricated at normal temperature) as afunction of the curing time From the figure it is envisagedthat the compressive strength of the nanocement mortarincreases gradually with increase in curing time up to 14days Beyond two weeks of curing compressive strengthbecomes almost constant It indicates that 14-day curing issufficient for nanocement mortar to gain maximum strengthwhereas for ordinary Portland cement based mortar 28-daycuring is essential to gain adequate strength Therefore it isassessed that the chemically synthesized nanocement has theability to produce adequate strength of the mortar within14-day curing which in turn reduces the time required forconstruction

Viewing in light of the above results it is revealedthat the method used in this investigation is an innovativescheme to produce an alternative cementitious material ofthe nanoscale particle size In fact in this investigation analternative pathway is followed instead of the clinkering toproduce a cementitious material using pozzolanic material(nanosilica) infused with hydrated alumina Based on theresults reported above we are trying to explain plausiblechemical reactions involved in the synthesis of nanocementand its overall performances as well Figure 9 represents aplausible model associated with synthesis of nanocementInitially the starting material sodium aluminate (NaAlO

2)

was dissolved in alkaline water at 90∘C to form a glassychain of sodiated aluminium hydroxide and at the sametime nanosilica was dissolved in water to form a high densityhydrated gel Afterwards mixing of the sodiated aluminiumhydroxide glassy gel with the high density gel of hydratedsilica leads to forming sodium aluminum silicate compounds[5 25] Heat evaporation process influences the nucleation


HydrolysisPolymerization


Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2

Figure 9 Plausible model for chemical synthesis of the nanocement using bottom-up nanotechnology

NaAlO2 + NaOH + H2O NaAl(OH)4

NaAl(OH)4 Al O + H2OAlNa+

n

minus

SiO2 + H2O Si O Si OHn

Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n

Figure 10 Plausible reaction scheme for the synthesis of nano cement

and crystallization of the sodium aluminum silicate com-pounds The plausible reaction schemes are represented inFigure 10 Furthermore to increase the calcium ion contentin synthesized cementing material ion substitution was donein the presence of calcium nitrate Ca(NO

3)2shown in (5)

of the Figure 10 The synthesized material was then used forthe fabrication of nanocement based mortar In the presentinvestigation the cementitiousmaterial was synthesized from

the pozzolanic material (nanosilica) infused with hydratedalumina using the hydrothermal method Additionally theoccurrence of the hydration reaction among the chemicalphases of the synthesized material is difficult in the presenceof the water only This is may be due to the lack of thedriving force to initiate the hydration reaction in the presenceof water Hence the use of an alkali activator in aqueoussolution may achieve the driving force to allow the hydration


35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN

N (Na2CO3 nitrate)S (Na8Al6Si6O24(OH)2(H2O)2 sodalite syn)

G (CaAl2Si2O8) 4H2O gismondine)

Figure 11 X-ray diffraction pattern of the chemically synthesizednanocement

reaction and leads to hardening of the cementitious materialTherefore for hydration an activated sodiumhydroxide solu-tion was used Accordingly the alkaline hydration reactionof the alternative cementitious material possibly producessodium andor calcium alumino silicate based compoundssuch as sodalite natrite gismondine calcium silicate hydrategel sodium alumino silicate hydrate gel and calcium sodiumalumino silicate hydrate gel [5 26] The crystalline com-pounds such as sodalite (Na

8Al6Si6O24(OH)2 2H2O) natrite

(Na2CO3) and gismondine (CaAl

2Si2O8 4H2O) formed

by alkaline hydration of nanocement are identified in X-ray diffractogram of hydrated nanocement represented inFigure 11 However the gel compounds are not identified inthe X-ray diffraction pattern due to their poor crystallinenature Therefore to analyze hydrated compounds and toestablish their structures MAS-NMR in conjugation withFTIR TG and DSC are required to be performed in thefuture As it seems from the above the alkaline hydrationof the chemically synthesized cement produces various geland crystalline compounds which may lead to develop themicrostructure at the nano- and microscale level of thehydrated nanocement Therefore it can be anticipated thatthe performance of the nanocement may be controlled bythe dispersion of the crystalline component over the gelcompounds which in turn leads to filling of the capillarypores at the nano- and microscale level Accordingly it isapparent that the reduction of the capillary pores increasesthe efficiency of the interfacial transition zone of hydratedcement which in turn leads to increase in the strengthof the mortar samples In Figure 12 a plausible model hasbeen represented in favor of the development of hydratedproduct into chemically synthesized nanocement system Asit is confirmed from Table 3 that the particle size of thesynthesized cement belongs in nanometer level therefore itis expected that the higher surface area would be exposed forthe hydration reaction [27] which in turn leads to developingof strength in mortar or concrete rapidly and consequentlyminimizes the time of construction

Viewing in light of the hydrothermal synthesis of thecementitious material (nanocement) it is apparent that theraw materials used in this investigation are not carbonbased Accordingly the process steps followed to producenanocement are not responsible to emit CO

2 Therefore it is

confirmed that the CO2will not emit during the synthesis of

the nanocement using the hydrothermal method Howeverit is reported elsewhere that during the production of the1 ton of Portland cement sim700ndash800 kg CO

2is liberated [2]

Usually the limestone is used as a primary raw materialfor the production of the Portland cement which is mainlycomposed of CaCO

3(calcium carbonate) When the raw

materials are heated up to 1450∘C in the rotary kiln it emitsenormous CO

2[28] Additionally it is also reported that

the CO2is emitted during the calcination of the calcareous

raw materials to produce CaO [29] Accordingly reviewingthe worldwide report it is considered that around 7 ofthe total man-made CO

2is emitted during the cement

production [29] Therefore it is expected that the synthesisof the nanocement using hydrothermal procedure is aninitial alternative approach which will avoid the CO

2emis-

sion

4 Conclusion

The present investigation offers an innovative idea to synthe-size nanocement utilizing the hydrothermal method insteadof the high temperature clinkeringmethodwhich emits enor-mous carbondioxide during the production of cement In thisinvestigation the hydrothermal synthesis of the nanocementfrom nanosilica and sodium aluminate is considered as abottom-up nanotechnology Based on the physical propertiesanalyses the particle size specific gravity and fineness ofthe synthesized material are estimated to be 167 nm 211and 3582400 cm2g respectively Hence from the result it isassessed that the product obtained by the chemical synthesismethod is a nanomaterial Additionally FE-SEM analysisproves that the average particle size of the synthesizedmaterial is retained at nanoscale level Additionally based onthe chemical composition analysis in conjugation with EDXanalysis it is revealed that the synthesized material containsidentical chemical oxide phases with commercially availablecement Therefore it is considered that the synthesizedmaterial is a type of cementitious material Furthermorebased on the setting time measurement it is concluded thatthe synthesized nanocement follows Korean standard in itssetting behavior Finally viewing in light of the mechanicalproperty analysis it is assessed that the newly developedmaterial shows cementing ability with superior mechanicalperformance as compared to that of the commercially avail-able cement Based on the critical analysis of the resultsa plausible model as well as a reaction scheme has beenestablished in favor of the synthesis and hydration of nanoce-ment Finally it is concluded that the chemically synthesizedcementitious material (nanocement) not only improves thephysical and mechanical performance of the mortar andconcrete but also brings several encouraging impacts to thesociety including reduction of the CO

2emission


Fine aggregate

Crystalized sodiumcalciumalumino silicate layer

Silicate tetrahedra

Cation

Hydrated product layerFine aggregate


Silicate tetrahedra

Cation

NaOH-water

ldquoAlrdquo bridging site


+Nanocement after hydration

Nanocement

Figure 12 Plausible model based on hydration of nanocement and probable structure of the expected hydrated product that is sodium-calcium-aluminosilicate hydrate

Conflict of Interests

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

Acknowledgment

The authors would like to acknowledge BK21 Republic ofKorea for their financial support to pursue this researchprogram

References

[1] J Jacobsen M S Rodrigues M T F Telling et al ldquoNano-scalehydrogen-bond network improves the durability of greenercementsrdquo Scientific reports Nature vol 3 article 2667 2013

[2] V M Malhotra ldquoRole of fly ash in reducing greenhousegas emissions during the manufacturing of portland cementclinkerrdquo httpwwwwatanconcomdocumentationtechnicalMalhotra - Role of Fly Ash in reducing GGEpdf

[3] P Balaguru and K Chong ldquoNanotechnology and concreteresearch opportunitiesrdquo in Proceedings of the ACI Session onNanotechnology of Concrete Recent Developments and FuturePerspectives Denver Colo USA November 2006 httpspan-therfileuwmedusobolevwwwACI2-Balaguru-ACI-Fpdf

[4] A K Mukhopadhyay ldquoNext-generation nano-based concreteconstruction products a reviewrdquo in Nanotechnology in CivilInfrastructure A Paradigm Shift K Gopalakrishnan B Bir-gisson P Taylor and N O Attoh-Okine Eds pp 207ndash223 Springer Berlin Germany 2011 httplinkspringercomchapter1010072F978-3-642-16657-0 7page-1

[5] P Mondal Nanomechanical properties of cementitious materials[Doctoral thesis] Northwestern University 2008

[6] R JMyers S A Bernal R SanNicolas and J L Provis ldquoGener-alized structural description of calcium-sodium aluminosilicatehydrate gels the cross-linked substituted tobermorite modelrdquoLangmuir vol 29 no 17 pp 5294ndash5306 2013

[7] E R Ylmen Early hydration of portland cementmdashan infraredspectroscopy perspective complemented by calorimetry and scan-ning electron microscopy [PhD thesis] Chalmers University ofTechnology Gothenburg Sweden 2013

[8] B Han X Yu and J Ou ldquoMultifunctional and smart carbonnanotube reinforced cement-based materialsrdquo in Nanotechnol-ogy inCivil Infrastructure A Paradigm Shift K GopalakrishnanB Birgisson P Taylor and N O Attoh-Okine Eds pp 1ndash47Springer Berlin Germany 2011

[9] L Raki J Beaudoin R Alizadeh J Makar and T Sato ldquoCementand concrete nanoscience and nanotechnologyrdquoMaterials vol3 no 2 pp 918ndash942 2010

[10] R Panneer Selvam K D Hall V J Subramani and S J MurrayldquoApplication of nanosciencemodeling to understand the atomicstructure of C-S-Hrdquo in Nanotechnology in Civil Infrastructure aParadigm Shift K Gopalakrishnan Ed pp 87ndash102 SpringerBerlin Germany 2011

[11] J Makar ldquoThe effect of SWCNT and other nanomaterials oncement hydration and reinforcementrdquo in Nanotechnology inCivil Infrastructure K Gopalakrishnan B Birgisson P Taylorand N O Attoh-Okine Eds pp 103ndash130 Springer BerlinGermany 2011

[12] M Kutschera L Nicoleau and M Brau ldquoNano-optimizedconstruction materials by nano-seeding and crystallizationcontrolrdquo inNanotechnology in Civil Infrastructure K Gopalakr-ishnan B Birgisson P Taylor and N O Attoh-Okine Eds pp175ndash205 Springer Berlin Germany 2011

[13] B Bhuvaneshwari S Sasmal and N R Iyer ldquoNanoscienceto nanotechnology for civil engineeringmdashproof of conceptsrdquoin Proceedings of the 4th WSEAS International Conference on


Recent Researches in Geography Geology Energy Environmentand Biomedicine (GEMESED rsquo11) 2011 httpwwwwseasuse-libraryconferences2011CorfuGEMESEDGEMESED-40pdf

[14] K L Scrivener ldquoNanotechnology and cementitious materi-alsrdquo in Nanotechnology in Construction 3 Proceedings of theNICOM3 Z Bittnar P J M Bartos J Nemecek V Smilauerand J Zeman Eds pp 37ndash42 Springer Berlin Germany 2009

[15] E J Garboczi ldquoConcrete nanoscience and nanotechnologydefinitions and applicationsrdquo inNanotechnology inConstruction3 Proceedings of the NICOM3 Z Bittnar P J M Bartos JNemecek V Smilauer and J Zeman Eds pp 81ndash88 SpringerBerlin Germany 2009

[16] H Li H Xiao J Yuan and J Ou ldquoMicrostructure of cementmortar with nano-particlesrdquo Composites B vol 35 no 2 pp185ndash189 2004

[17] B Jo J Choi and S Kang ldquoAn experimental study on the char-acteristics of chemically synthesized nano-cement for carbondioxide reductionrdquo Advanced Materials Research vol 148-149pp 1717ndash1721 2011

[18] KSL 5110 2001 ldquoTestingmethod for specific gravity of hydrauliccementrdquo Bureau of Korean standard Seoul Republic of Korea2006

[19] KSL 5108 2007 ldquoTesting method for setting time of hydrauliccement by vicat needlerdquo Bureau of Korean standard SeoulSouth Korea 2007

[20] KSF 2405 ldquoTesting method for compressive strength of con-creterdquo Seoul South Korea Bureau of Korean Standard 2010

[21] B Jo J Choi and S Kang ldquoAn experimental study on the char-acteristics of chemically synthesized nanocement for carbondioxide reductionrdquo Journal of Ceramic Processing Research vol12 no 3 pp 294ndash298 2011

[22] S Chakraborty S P Kundu A Roy B Adhikari and S BMajumder ldquoEffect of jute as fiber reinforcement controllingthe hydration characteristics of cement matrixrdquo Industrial andEngineering Chemistry Research vol 52 no 3 pp 1252ndash12602013

[23] B-W Jo S Chakraborty andKW Yoon ldquoA hypotheticalmodelbased on effectiveness of combined alkali and polymer latexmodified jute fibre in controlling the setting and hydrationbehaviour of cementrdquo Construction and Building Materials vol68 pp 1ndash9 2014

[24] KSL 5201 2013 ldquoPortland cementrdquo Bureau of Korean standardSeoul South Korea 2013

[25] E H kim Understanding effects of siliconaluminum ratio andcalcium hydroxide on chemical composition Nanostructure andcompressive strength for metakaolin geopolymers [MS thesis]University of Illinois Urbana-Champaign Ill USA 2012httpswwwidealsillinoisedubitstreamhandle214234257Kim Ericpdfsequence=1

[26] M Sathupunya E Gulari and S Wongkasemjit ldquoANA and GISzeolite synthesis directly from alumatrane and silatrane by sol-gel process and microwave techniquerdquo Journal of the EuropeanCeramic Society vol 22 no 13 pp 2305ndash2314 2002

[27] J Byung-Wan S Chakraborty K Heon Kim and Y Sung LeeldquoEffectiveness of the top-down nanotechnology in the produc-tion of ultrafine cement (sim220 nm)rdquo Journal of Nanomaterialsvol 2014 Article ID 131627 9 pages 2014

[28] M J Gibbs ldquoCO2

emissions from cement productionGood Practice Guidance and Uncertainty Management inNational Greenhouse Gas Inventories Industrial 182 Processes

Sectorrdquo httpwwwipcc-nggipigesorjppublicgpbgp3 1Cement Productionpdf

[29] Cement Raw Materials British Geological Survey MineralProfile Natural Environmental Research Council Office ofthe Deputy Prime Minister 2005 httpwwwscribdcomdoc217671476comm-profile-cement-pdf

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


Table 1 Effect of different nanomaterials on the performances of the cement composite

Primary material Additivesprocedure Particle Size Effectperformance Reference

Portland cement

Nanosize ingredients suchas alumina silica particlesand carbon nanotubes wereadded

lt500 nmNanocement can create new materialsdevices and systems at the molecularnano- and microlevel

[3]

Portland cement

Nano-SiO2 nano-TiO2nano-Al2O3 nano-Fe2O3and nanotubenanofibreswere added

sim20 nm and 100 nmCan produce concrete with superiormechanical properties as well asimproved durability

[4]

Portland cementSingle wall and multiwallcarbon nanotubes wereadded

mdashCement materials showed superiormechanical electrical and thermalproperties

[8]

Ordinary Portlandcement

Spherical nanoparticlenano-SiO2 nano-Fe2O3and multiwall carbonnanotubes were added

1ndash100 nmSignificant improvement incompressive strength as well as Youngrsquosmodulus and hardness of the concrete

[9]

Portland cement Spherical nano-Fe2O3 andnano-SiO2 were added

15 nm Mortar showed higher compressivestrength as well as flexural strength [16]

Nano-SiO2nano-NaAlO2 andnano-Ca(NO3)2

Using the hydrothermalmethod a new type ofcement material isproduced

167 nm

A new cementitious material isproduced using pozzolanic materialinfused with hydrated alumina whichavoids CO2 emission able to controlmechanical performance of the mortar

Present work

performance smart and sustainable construction materialsby the tuning of the existing processes together in combi-nation with the nanotechnology [4 8 9] At the outset itwas anticipated that the mechanical performances and thedurability of concrete could be improved by reducing theoverall porosity of the concrete [4] It can only be possibleif the capillary pores of the cement paste are reduced or thediffusion of the pore solution is restricted by the assimilationof some additives to a similar range of capillary pore sizes[4 9 10] Thus the bottom-up nanoengineered constructionprocess is used to reduce nanocapillary pores of cementpaste [4 8] Accordingly the process is a very successfuland promising one which encompasses the structure at thenanoscale level to develop multifunctional cement compos-ites with superior mechanical performance and durability[4 9 10] Perhaps the nanoengineered construction processis mainly based on the incorporation of nanoscale materialssuch as spherical nanomaterial (namely nano-SiO

2 nano-

TiO2 nano-Al

2O3 nano-Fe

2O3 etc) nanofiber (namely

carbon nanotube (CNT) and carbon nanofibers (CNF)) andnanoclay into cement system during mixing of cement andaggregate to produce concrete [4 7ndash10] In view of thatthe nanoengineered process potentially brings a range ofnovel properties such as high ductility self-healing self-crackcontrolling ability low electrical resistivity and self-sensingcapabilities [11] In addition to the nanoparticle incorporationin concrete system modification of the aggregate surfaceusing nanoporous thin film to produce nanoengineeredconstruction material is also reported elsewhere in orderto improve the interfacial transition zone (ITZ) in betweenaggregate and cement paste [12ndash16] Moreover in a previousresearch we have demonstrated that the chemical synthesis of

a cementitious material using noncarbon based raw material[17] Table 1 summarizes the effect of different nanomaterialsand procedures on the performances of the nanoengineeredconcrete

Reviewing the literature it is prophesied that the incorpo-ration of the external nanomaterial into cement system hassucceeded to improve physical characteristics mechanicalproperties and novel performances of cementitious materi-als however the process is unable to reduce CO

2emission

during the production of cement From the review of theexisting literature it is apparent that the production ofthe cementitious material without emitting CO

2has not

been studied yet In a previous study [17] we have demon-strated the chemical synthesis of the alternative cementitiousmaterial however the structure property relation was notevaluated In order to minimize the emission of CO

2and

to produce alternative cementitious material we have triedto establish an innovative alternative pathway In this inves-tigation we have studied the chemical synthesis structureproperty correlation and application of the cementitiousmaterial The chemical synthesis of nanocement is demon-strated to be very effective not only to enhance the physicaland mechanical performances of cement based material butalso to control the CO

2emission during its production

2 Experimental Program

In this investigation we have set a systematic experimentalprogram to synthesize an alternative cementitious material(nanocement) using the hydrothermal method For the syn-thesis of the nanocement using the hydrothermal method


















24 Characterization






Water variation
























001 01 10

4

8

12

16

20

Chan

nel (

)

Channel ()

Pass

()

0

20

40

60

80

100

Pass ()





3S)





(a) (b)




Nanocement 1009 200 2505 3262 3024




O

Ca Na

Al

Si

Ca

0 1 2 3 4 5 6 7 8 9 10

(keV)

3




20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)


Temperature (∘C)




0

10

20

30

40


Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM


0

10

20

30

40

50

60


Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




















24 Characterization






Water variation
























001 01 10

4

8

12

16

20

Chan

nel (

)

Channel ()

Pass

()

0

20

40

60

80

100

Pass ()





3S)





(a) (b)




Nanocement 1009 200 2505 3262 3024




O

Ca Na

Al

Si

Ca

0 1 2 3 4 5 6 7 8 9 10

(keV)

3




20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)


Temperature (∘C)




0

10

20

30

40


Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM


0

10

20

30

40

50

60


Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







Water variation
























001 01 10

4

8

12

16

20

Chan

nel (

)

Channel ()

Pass

()

0

20

40

60

80

100

Pass ()





3S)





(a) (b)




Nanocement 1009 200 2505 3262 3024




O

Ca Na

Al

Si

Ca

0 1 2 3 4 5 6 7 8 9 10

(keV)

3




20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)


Temperature (∘C)




0

10

20

30

40


Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM


0

10

20

30

40

50

60


Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials















001 01 10

4

8

12

16

20

Chan

nel (

)

Channel ()

Pass

()

0

20

40

60

80

100

Pass ()





3S)





(a) (b)




Nanocement 1009 200 2505 3262 3024




O

Ca Na

Al

Si

Ca

0 1 2 3 4 5 6 7 8 9 10

(keV)

3




20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)


Temperature (∘C)




0

10

20

30

40


Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM


0

10

20

30

40

50

60


Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




(a) (b)




Nanocement 1009 200 2505 3262 3024




O

Ca Na

Al

Si

Ca

0 1 2 3 4 5 6 7 8 9 10

(keV)

3




20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)


Temperature (∘C)




0

10

20

30

40


Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM


0

10

20

30

40

50

60


Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




20 40 60 80 100 120

0

100

200

300

400

500

600

Setti

ng ti

me (

min

)


Temperature (∘C)




0

10

20

30

40


Com

pres

sive s

treng

th (M

Pa)

MN

-W1

MN

-W2

MN

-W3

MN

-W4

MN

-W5

MN

-W6

MN

-W7

CCM


0

10

20

30

40

50

60


Com

pres

sive s

treng

th (M

Pa)

MN

-A3

CCM

MN

-A1

MN

-A2

MN

-A4

MN

-A5

MN

-A6

MN

-A7

MN

-A8




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




0

10

20

30

40

50


Com

pres

sive s

treng

th (M

Pa)

CCM

MN

-F1

MN

-F2

MN

-F3

MN

-F4





0 5 10 15 20 25 30

54

56

58

60

62

64

Com

pres

sive s

treng

th (M

Pa)

Curing time (days)


R2 = 0989





2)





Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






Sol

Sol

Low dense gel

High dense gel

Ripening

Ripening

Mixing

Mixing

Evaporation

Hea

t

Nanocement

NaOH

H2O

NaAlO2

Nano-SiO2




n

minus


Si O Si OH

n

+ Al O Al

n

minusNa+

Si O Al

n

minus Na+

+ Si O Si

n

O Al O Al

n

minus

Ca(NO3)2

Si O Al

n

minus

Ca2+ Al O Si

n

Na+

minus

Si O Si O Al O Al

n

minusminusCa2+

Al O Al

n

O Si O Si

n

(1)

(2)

(3)

(4)

(5)

n



3)2shown in (5)




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




35000

30000

25000

20000

15000

10000

5000

0

Inte

nsity

(cps

)

0 10 20 30 40 50 60 70 80

2120579 (∘)

S

NG

S

S

S

S

S

S

S SS

S S SS S S

SSSSN

N

G NNN GG NN







2Si2O8 4H2O) formed



2 Therefore it is



2is liberated [2]









2emis-

sion

4 Conclusion


2emission


Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


References









































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




Fine aggregate


Silicate tetrahedra

Cation



Silicate tetrahedra

Cation

NaOH-water




Nanocement




Acknowledgment


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



research article synthesis of a cementitious material nanocement using bottom...

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