properties and internal curing of concrete containing...

Research ArticleProperties and Internal Curing of Concrete Containing RecycledAutoclaved Aerated Lightweight Concrete as Aggregate

Teewara Suwan12 and Pitiwat Wattanachai1

1Department of Civil Engineering Faculty of Engineering Chiang Mai University 239 Huay Kaew Road Muang DistrictChiang Mai 50200 Thailand2Center of Excellence for Natural Disaster Management (CENDIM) Chiang Mai University 239 Huay Kaew RoadMuang District Chiang Mai 50200 Thailand

Correspondence should be addressed to Pitiwat Wattanachai pitiwatengcmuacth

Received 1 June 2017 Accepted 10 July 2017 Published 20 August 2017

Academic Editor Tung-Chai Ling

Copyright copy 2017 Teewara Suwan and Pitiwat WattanachaiThis is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Global warming is a vital issue addressed to every sector worldwide including the construction industry To achieve the conceptof green technology many attempts have been carried out to develop low-carbon footprint products In the construction sectorAutoclavedAeratedConcrete (AAC) has becomemore popular and beenmanufactured tomeet the construction demandHowevererrors frommanufacturing process accounted for approximately 3 to 5 of the AAC productionThe development of AACwaste aslightweight aggregate in concrete is one of the potential approaches which was extendedly studied in this paperThe results showedthat the compressive strength of AAC-LWA concrete was decreased with an increase in volume and coarse size The optimummixproportion was the AAC aggregate size of 1210158401015840 to 3810158401015840 with 20 to 40 replacement to normal weight aggregate Internal curingby AAC-LWA was also observed and found to provide sufficient water inside the specimens leading to an achievement in highercompressive strengthThemain goal of this study is not only utilising unwanted wastes from industry (recycling of waste materials)but also building up a new knowledge of using AAC-LWA as an internal curing agent as well as the production of value-addedlightweight concrete products

1 Introduction

To achieve the concept of green construction technologymany attempts have been carried out to develop low-carbonfootprint products or techniques An approach of trans-forming wastes from any industrial sectors to become anew raw starting material for other industries has receivedmuch more attention as a zero-waste society Commonly thesimplest eliminating of industrial wastes is to utilise themas cement or concrete replacement for example cementadditives or concrete aggregates In Thailand although aconventional masonry wall is made from local clay-brickswith launching of Lightweight Autoclaved Aerated Concrete(AAC) blocks they turn into a new choice for engineers andbuilders therefore becoming more and more popular in theconstruction industry However it was reported that scrapsand wastes from overall AAC block production accounted

for approximately 3 to 5 (58 tonnes monthly) resulting ina huge number of AAC residues heading directly to a land-filled site (Figure 1) Developing AAC wastes as a lightweightaggregate in concrete production is one of the potentialapproaches that not only is beneficial for utilising industrialby-products and the reduction of energy consumption butalso is beneficial for a strength improvement by internalcuring and a reduction of final concrete weight [1 2]

External curing is a commonmethod to acquire sufficientPortland cement hydration which can be achieved by pre-venting moisture loss on surfaces wrapping with any wet-covers or even submerging the concrete samples in the waterbath However in some cases the effectiveness of externalcuring may be limited due to an unsatisfied penetrationof curing-water into the samples by physical barrier orgeometry of the concrete components [3] Internal curing isan alternative approach introducing internal water reservoir

HindawiAdvances in Materials Science and EngineeringVolume 2017 Article ID 2394641 11 pageshttpsdoiorg10115520172394641

2 Advances in Materials Science and Engineering

Figure 1 Scraps of AAC block production

for curing purpose inside the concretemixtures It has alreadybeen proved that internal curing can significantly enhancethe strength and reduce an autogenous shrinkage of the finalconcrete products [4 5] Any porous lightweight materialcan be used as an internal curing aggregate (eg vermiculiteperlite pumice scoria expanded shale expanded clay andcrushed-AAC wastes) [6 7] as they could absorb waterduring preparation and mixing and then gradually releasereserved water inside the mixtures during hardening process[8] Moreover the rough surface and coarse pore structureof those lightweight aggregates can also contribute to aninterlocking manner on transition zones between cementpaste and aggregate (interconnected surfaces) leading to animprovement in mechanical properties [9]

The main aim of this paper is to utilise available localAAC waste as a lightweight aggregate in concrete produc-tion which could allow converting industrial wastes intovalue-added products Lightweight and highly uniformlydistributed porosity are key characteristics of AAC that couldserve as an internal curing material to provide sufficientcuring condition for concrete constructionThe suitable sizesand optimum replacement percentage of AAC aggregatewere investigated as well as the final properties of fresh andhardened concrete during the internal curing approach

2 Materials and Preparations

Portland cementwas a commercial grade type Iwith a specificgravity of 315 Local river sand was used as a fine aggregatewith specific gravity and fineness modulus of 239 and 290respectively The moisture content of sand was 080 with abulk density of 1645 kgm3 Coarse aggregate was commer-cial grade gravel from local suppliers The specific gravitymoisture content and bulk density were 270 050 and1540 kgm3 respectively AAC wastes were collected fromPCC Autoclave Concrete Company Limited Chiang MaiThailand Its specific gravitywas 106with a dry-unitweight of360 kgm3 As-received AAC with a water absorption valueof 28 to 30 was crushed into a smaller size by a standardJaw crusher (Figure 2)

The gradation of AAC coarse aggregates was then anal-ysed by the US standard sieve analysis The effective coarsesize used in this study was between 3810158401015840 (95mm) and 3410158401015840

Table 1 Grading of crushed-AAC aggregates

Sieve size (mm) Percent retained on the sieve210158401015840 (5080) 131110158401015840 (2540) 9183410158401015840 (1905) 18221210158401015840 (1270) 20123810158401015840 (953) 11354 (475) 1114Pan 2867

Table 2 Mixture labels and descriptions

Label DescriptionNC Normal weight aggregate concreteLWA Lightweight aggregate

LWA20 Concrete with 20 lightweight aggregatereplacement



S1 Lightweight aggregate with class size of 110158401015840ndash3410158401015840



S4 Lightweight aggregate with mixed class size of110158401015840ndash3410158401015840 to 3410158401015840ndash1210158401015840 to 1210158401015840ndash3810158401015840 by 20 40 40

(190mm) which accounted for around 50 of the overallamount of AAC aggregates and has an average finenessmodulus of 720 (Table 1) It is noted that the majorityof effective AAC-LWA size values were 3410158401015840 1210158401015840 and3810158401015840 and the size classes (as indicated with S1 to S4) ofcoarse aggregates replacement were therefore employed inthe experiment Mixture labels and descriptions of concretemixtures including size classes of AAC-LWA are illustratedin Table 2

The coarse aggregate commercial grade and size distri-butions are in the comparison ofASTMC33with size number

Advances in Materials Science and Engineering 3

Figure 2 Crushed-AAC scraps into AAC aggregates

0102030405060708090

100

1 10 100Sieve size (mm)

LowerUpper

NWCA

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

Figure 3 Size distribution of normal weight coarse aggregates(NWCA) used in accordance with ASTM C33 Size Number 67

67 Figure 3 shows the size distribution of normal weightcoarse aggregates (NWCA) used in NCmixture It was foundthat the size distributions of normal weight aggregate arebetween 1210158401015840 and 3810158401015840 and mostly filled in the upper andlower boundaries of ASTM C33 size number 67 standard Inaddition as varied in class size of S1ndashS4 the size distributionsof AAC-LWA replacement to normal weight aggregate by 2040 and 60 (LWA20 LWA40 and LWA60) are also plottedagainst upper and lower boundaries of ASTMC33 number 67criteria

As specific AAC-LWA class sizes (S1ndashS4) were replaced toa normal gradation of commercial grade gravel the graphs ofsize distribution therefore started to shift to the upper limitof the ASTM C33 boundaries (Figure 4) It can be seen thata bundle of all LWA20 class sizes are aligned closely insidethe upper boundary (Figure 4(a)) Moreover the lines of sizedistribution were apparently shifted to the right beyond theupper limit when the amount of AAC-LWA replacementincreased from LWA40 (Figure 4(b)) to LWA60 (Figure 4(c))in all class sizes Thus the presence of AAC-LWA aggregatesdoes not only affect the overall gradation of concrete coarseaggregate but could also affect the mechanical properties ofthe final result of hardened concrete

3 Experimental Details

31 Mixture Designations Mixture designation was carriedout following ACI 2111 standard for concrete mixing Incontrolled mixture (Normal Concrete NC) with water-to-cement (wc) ratio of 035 normal weight aggregates wereadded with the largest particle size of 3410158401015840 The requiredconcrete slump was set to 5 to 10 cm Apart from that inthe mixtures with AAC wastes as lightweight aggregates(AAC-LWA) the volume of normal weight aggregates wassubstituted by the saturated surface-dry (SSD) AAC-LWAnamely 20 40 and 60 respectively It is noted that thetotal weight of AAC-LWA replacement was calculated fromthe same volume of normal aggregate in a cubic meterof concrete For example of 20 AAC-LWA replacement(LWA20) as bulk density of normal weight aggregates andAAC-LWA were 1540 and 360 kgm3 respectively 188 kg ofnormal weight aggregates was replaced by 46 kg of AAC-LWA All concrete mixtures were mixed in a tilting drummixer until reaching suitable conditions The fresh concretewas then carried out for workability testing and placed in theprepared moulds After 24 hours all concrete samples weredemoulded and kept in specific designed-curing conditionswater and air curing Mixture proportions are as presented inTable 3

32 Analytical Methods Properties of fresh concrete werecarried out by slump test and flow test Concrete slump testwas done with ASTMC143The slump value of 10 cm was setin accordance with ACI 213R-87 which is recommended forthe construction of slab column and bearing wall structuresFlow ability of concrete was measured by using flow tablealong with ASTM C124 standard Properties of hardenedconcrete were carried out with both standard and minutecompressive strength tests After demoulding (in the next 24hours) all samples were cured in water or in the air untilreaching their testing ages of 1 3 7 and 28 days Weightand dimension of all samples were measured before furtherhandling for the apparent density calculation Standard com-pressive strength test of all cylindrical specimens (15 cm diaand 30 cm height) was obtained by using Universal TestingMachine (UTM) in accordance with ASTM C39 An opticalmicroscope was used to observe interfacial transition zone(ITZ) of AAC-LWA and cement paste


S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(a)

S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(b)


0102030405060708090

100

S1S2S3

S4LowerUpper

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(c)

Figure 4 Size distribution of AAC-LWA of (a) LWA20 (b) LWA40 and (c) LWA60 in accordance with ASTM C33 Size Number 67 Thegreen curve refers to the normal weight coarse aggregates (NWCA) (as shown in Figure 3) for comparison to S1ndashS4

Table 3 Details of mixture designation (kgm3)

Mixture ACC-LWAreplacement () Class size Portland

cement Water Fineaggregate

Coarseaggregate

ACCaggregate

NC mdash mdash 571 200 588 938 mdash

LWA20

20 S1 571 200 588 750 4620 S2 571 200 588 750 4620 S3 571 200 588 750 4620 S4 571 200 588 750 46

LWA40

40 S1 571 200 588 563 9340 S2 571 200 588 563 9340 S3 571 200 588 563 9340 S4 571 200 588 563 93

LWA60

60 S1 571 200 588 375 13960 S2 571 200 588 375 13960 S3 571 200 588 375 13960 S4 571 200 588 375 139


Exteriorzone

150mm

150mm

zoneInterior

15 mm

Figure 5 Cutting layout of 15 times 15 times 150mm prisms

Minute compressive strength (3 times 3 times 3mm cubicspecimen) was introduced and carried out in this test toidentify the effect of AAC-LWA on internal curing [10]To prepare minute strength test samples the 150 times 150 times150mm concrete cube was mixed and cured in designed-conditions Three locations of the concrete cube (exteriorzone and interior zones) were cut into 15 times 15 times 150mmprisms (Figure 5) Each prismwas then sliced into 3mm thicklayers with the dimensional length of 3 times 15times 15mm namelyL1 L2 and L3 It is noted that L1 was a layer right next tothe AAC-LWA while L2 and L3 were further aligned over(Figure 6)Those layers (L1 L2 and L3) were finally cut into 3times 3 times 3mm cubes (Figure 7) and then tested with a standardproving ring attached to the UTM

4 Results and Discussions

41 Slump Test The results of concrete slump test are illus-trated in Figure 8The AAC-LWA size classes as indicated byS1 S2 S3 and S4 (see Table 2) had no significant difference inthe test The slump of controlled concrete (NC) was 580 cmwhile slump values of AAC-LWA concrete tended to increasewith a higher percentage of AAC aggregate replacement forexample from around 750 cm (LWA20) to around 1060 cm(LWA60) In fact sharp shape and rough surface of AAC-LWA could decrease the slump value due to interlocking andinternal friction among materials [11] However in this casethe slump value was mainly dominated by water retainabilityextra water on the surface of AAC particlesWater-to-cementratio was therefore raised leading to an increase of concreteslump value A similar result was also reported by Singh andSiddique (2016) that highly absorption materials (eg coal-bottom ash) can act as a water reservoir and could raise thefinal wc ratio of concrete mixtures [12]

42 Flow Test There was no significant difference in flowability between controlled mixture (NC) and AAC-LWAmixtures An average flow of AAC-LWA concrete seemed tobe slightly decreased when the AAC aggregate replacementincreased The average flow value of NC was 533 whileaverage flow values of LWA20 LWA40 and LWA60 mixtureswere 55 56 and 53 respectively (Figure 9) However asthe flow valueswere in the range of 50 to 100 theAAC-LWAconcrete mixtures were classified in medium consistency

which could easily be placed and compacted into the mouldsduring a casting process

43 Apparent Density of Concrete Mixtures As presentedin Figure 10 the apparent density of controlled mixture(NC) was around 2380 kgm3 at 28 days of age Apartfrom that the overall apparent density of LWA20 concretewas slightly decreased approximately 3 to 4 to around2290 to 2310 kgm3 when compared with NCmixture WithLWA40 and LWA60 mixtures the apparent density wascontinuously decreased by 8 to 9 (2160 to 2180 kgm3) and13 to 15 (2030 to 2070 kgm3) respectively The similarresults were reported by Hossain et al (2011) and Topcu andIsikdag (2008) whose substituted normal weight aggregatesby pumice andperlite as concrete coarse aggregates [13] It canbe concluded that the overall density of AAC-LWA concretewas significantly decreased because of LWA replacement asits density was just 360 kgm3 In contrast the compressivestrength is the next issue which needs to be considered as themost crucial properties of hardened concrete

44 Standard Compressive Strength Test The standard com-pressive strength test by using cylindrical specimens wascarried out at 1 3 7 and 28 days of age The comparativestrength measurement between water and dry-air curingincluding its size classes was studied and is presented inFigures 11(a)ndash11(c)

It can be clearly seen that all mixtures cured in waterachieved higher strength than that of mixtures cured inthe dry-air as more degree of hydration was obtained [14]The size class of S4-AAC aggregate (see Table 2) receivedthe highest strength among S1 S2 and S3 classes due to awell gradation of the coarse aggregates in concrete mixturesaccording to ASTM C33 number 67 More compact structurewas also achieved as well as an appropriated interlocking ofwell-graded coarse aggregate Comparable strength improve-ment was obviously obtained from the higher density ofhardened cement paste in the interfacial transition zone (ITZ)by internal curing [15] The examples of normal-bonding(NWCA) and well-bonding (AAC-LWA) are as presented inFigure 12 It can be seen that the failure of normal-bondedNWCA occurred at cement paste while well-bonded AAC-LWAwas at AAC aggregate Apart from the strength propertyof each aggregate AAC-LWAclearly exhibited a terrific bond-ing performance at ITZ Nevertheless the final strength ofAAC as aggregate concrete was decreased when the amountof AAC-LWA increased because AAC has extremely lowload bearing capacity when compared with normal weightaggregate

45 Minute Compressive Strength Test Minute compressivestrength is a technique used to verify an effect of internalcuring by porous aggregate in the concrete mixtures Thecompressive strength of 3 times 3 times 3mm cube specimens ofLWA20 LWA40 and LWA60 mixtures (all with S4 class sizecured in the air) were tested and presented in Figure 13 Itcan be apparently seen that the strength of samples collectedfrom the exterior zone obtained lower strength than that


Exterior zone

Exterior zone

150mm

Interior zone

Interior zone3mm 3mm

15 mm

15 mm

LWA LWA 1 2 31 2 3

15 times 15 times 150ＧＧ

prism

Figure 6 Cutting layout of 3 times 15 times 15mm layers (L1 L2 and L3)

3mm

3mm

Figure 7 Cubic specimens in 3 times 3 times 3mm size

0

5

10

15

NC LWA20 LWA40 LWA60

Slum

p (c

m)

ACC-LWA concrete mixtures

S1 (1ndash34)S2 (34ndash12)


Figure 8 Slump values of NC and LWAmixtures

of the interior zone Moreover the strength of L1 sample(L1 the layer next to AAC aggregate) obviously achievedhigher mechanical strength than those of the faraway layersL2 and L3 (see Figure 6) In general more completion ofinternal hydration process of AAC-LWA could be achieved

0

10

20

30

40

50

60

70

80

Flow

()

NC LWA20 LWA40 LWA60ACC-LWA concrete mixtures



Figure 9 Flow values of NC and LWA concrete mixtures

by water retainability in the concrete mixture Especially forporous aggregates extra water for internal curing purposewas not only obtained from water absorption but also fromwater adsorption which directly affects the curing-water ofconcrete in later stage [16] Moreover the internal curing


Table 4 Differential percentage of minute compressive strength in layer 1 (L1) between 7 and 28 days of age

MixturesAir curing (AC) Water curing (WC)

L1 Ext (MPa) L1 Int (MPa) L1 Ext (MPa) L1 Int (MPa)7 d 28 d Δ 7 d 28 d Δ 7 d 28 d Δ 7 d 28 d Δ

NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)

Figure 10 Apparent density of NC and LWA concrete mixtures

process would also occurwith ldquocapillary suctionrdquo of which thetransferring of water occurs from larger pores to the smallerones In this study the capillary pores of AAC aggregates (50to 100 microns 120583m) were larger than that of average cementpaste pores (1 to 100 nanometers nm)

By this condition some reservedwater inAACaggregateswould therefore be transferred to cement paste across ITZincreasing hydration level to the cement bindersThe strengthimprovement in later age was mainly influenced by more C-S-H formation and denser microstructures [9] The usage ofAAC-LWA in saturated surface-dry (SSD) condition in thisstudy would provide higher strength in all cases than the as-receiveddry AAC-LWA [15]The reasons are that as-receivedAAC-LWA could actively absorb the water in the systemduring its initial stage of mixing Micropores and incompletemicrostructures would appear on ITZ leading to an adverseeffect on the final properties of concrete [15]The same trendsand results were obtained by theminute compressive strengthof S4-class size of LWA20 LWA40 and LWA60 cured inwater As far as sufficient curing water was served from bothexternal and internal sides the average strength of 3 times 3mmcubewas thus slightly higher than the others cured in the dry-open air condition (Figure 14)

46 The Strength Development and a Relationship betweenStandard and Minute Compressive Strength The strengthdevelopment of layer 1 (L1) minute compression test over7 and 28 days is presented in Table 4 While keeping NC

as a reference mixture the LWA20 achieved the greatestdifference of strength development in all conditions at 3400(AC L1 Ext) 5110 (AC L1 Int) 3333 (WC L1 Ext) and4280 (WC L1 Int) A huge differentiation of the L1 minutecompressive strength can be observed between exterior andinterior zones of LWA20 (2698 and 3532) and LWA40(3903 and 5499) mixtures as illustrated in Table 5 It isobviously seen that theminute compressive strength of the aircuring (AC) condition can be improved with internal curingregimes especially for the interior zone The optimum AAC-LWA proportions which would receive the most benefitfrom internal curing are in the range of LWA20 to LWA40mixtures

In contrast the highest minute compressive strength oflayer 1 (L1) was also plotted against standard cylindricalcompressive strength with S4 class size at 7 and 28 days ofage Figure 15 presents the relationship of that minute andstandard compressive strength of specimens cured in thedry-air curing condition (AC) in both their exterior zone(Figure 15(a)) and interior zone (Figure 15(b)) As mentionedearlier in Section 44 the average standard compressivestrength of AAC-LWA concrete decreased when the amountof AAC-LWA replacement increased from 351 MPa (7 d) and412 MPa (28 d) in LWA20 mixtures to around 262 MPa(7 d) and 281 MPa (28 d) in LWA60 mixtures However itis clearly seen that LWA20 and LWA40 mixtures seem toachieve higher strength than that of normal weight aggregateconcrete (NC)

Minute compressive strength (as presented in Section 45)of the interior zone is clearly higher than the exterior one dueto the internal curing of AAC-LWA with the highest value ofLWA20 mixture The investigation suggested that the 20 to40 AAC-LWA replacement (LWA20 and LWA40) could bean optimum proportion for AAC-LWA concrete

By this it can be explained that those proportions mainlyachieved the superior strength from normal weight aggre-gate while the suitable amount AAC aggregate replacementserved the extra amount of water for internal curing to thecement paste An increase of C-S-H formation not onlystrengthens the concrete matrices but also provides a well-bonding between AAC aggregate and cement paste at theirITZ The similar trend of strength development was foundin the specimens cured in water curing condition (WC)as shown in Figure 16 Additionally as mentioned beforeoverall compressive strength of both minute and standardspecimens was significantly higher than that of dry-air curingas sufficient water for curing purpose was obtained Despite


100

150

200

250

300

350

400

450

0 7 14 21 28

NC-WCS1-WCS2-WCS3-WCS4-WC

NC-ACS1-ACS2-ACS3-ACS4-AC

WCmdashwater curingACmdashair curing

Testing age (days)

Com

pres

sive s

treng

th (M

Pa)

(a) Compressive strength of LWA20

100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)

0 7 14 21 28Testing age (days)




(b) Compressive strength of LWA40



100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)



(c) Compressive strength of LWA60

Figure 11 Standard compressive strength test of NC and AAC-LWA concrete in different size classes (S1 to S4) at the age of 1 3 7 and 28days


Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)

Figure 12 Normal-bonded NWCA (left) and well-bonded AAC-LWA (right) with cement paste on interfacial transition zone (ITZ)

Table 5 Differential percentage of minute compressive strength in layer 1 (L1) between exterior and interior zone


L1 7 d (MPa) L1 28 d (MPa) L1 7 d (MPa) L1 28 d (MPa)Ext Int Δ Ext Int Δ Ext Int Δ Ext Int Δ

NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551

NC-AC LW20-AC LW40-AC LW60-AC NC-AC LW20-AC LW40-AC LW60-AC

Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

Exterior zone Interior zone

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)

Figure 13 Minute compressive strength of NC and LWA mixturesat L1 L2 and L3 cured in the air (7 and 28 days of age)

a slight difference in compressive strength between watercuring and air curing which water reserve of recycled AACaggregate seems not necessary to providemoisture for furthercement hydration process the effectiveness of external curingmay be limited due to an unsatisfied penetration of curingwater into the samples and the internal curing will thenenlarge the positive curing regime from inside the concretestructure in the real use applications (eg huge structure orconcrete component)

5 Conclusions

From the study conclusion can be summarised as follows(1)The slump values were affected by the amount of water

content The slump value tended to rise with an increase

Water curing (WC)Exterior zone Interior zone

NC-WC LW20-WC LW40-WC LW60-WC NC-WC LW20-WC LW40-WC LW60-WC

Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)

Figure 14 Minute compressive strength of NC and LWA mixturesat L1 L2 and L3 cured in the water (7 and 28 days of age)

of AAC-LWA replacement as extra water on aggregatersquossurface was obtained However flow values of all mixtureswere similar to normal weight aggregate concrete (NC) andclassified as medium consistency category with the flow of 50to 60(2)The apparent density was decreased when the amount

of AAC-LWA replacement increased from 2380 kgm3 (NC)to around 2050 kgm3 (LWA60) Although the minimumdensity in this test (2030 kgm3 in LWA60 mixture) did notmeet the criteria of lightweight concrete advised byACI 213R-87 at 1850 kgm3 the lower value in density can alternativelybe achieved by increasing AAC-LWA proportion or evenusing lightweight fine aggregates (eg lightweight sand orbottom ash)


000

050

100

150

200

250

300

NC-AC LW20-AC LW40-AC LW60-AC

Min

ute s

treng

th (M

Pa)

Mixtures

Air curing (AC)exterior zone

L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)

NC-AC LW20-AC LW40-AC LW60-ACMixtures

L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

Air curing (AC)interior zone

(b)

Figure 15 Relationship between standard and minute compressive strength of dry-air curing regime at (a) exterior zone and (b) interiorzone

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)

Water curing (WC)exterior zone

NC-WC LW20-WC LW40-WC LW60-WCMixtures

L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

Water curing (WC)interior zone

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)

Figure 16 Relationship between standard and minute compressive strength of water curing regime at (a) exterior zone and (b) interior zone

(3) The standard compressive strength by cylindricalspecimens was decreased with higher AAC-LWA proportionin both dry-air and water curing even though the watercuring achieved slightly higher compressive strength Themixed size of AAC-LWA (S4 class size) provided satisfactorygradation and superior strength than the single graded-aggregates (S1 S2 and S3)(4)The highest strength of minute compressive test was

achieved by 3 times 3 times 3mm cube located in layer 1 (L1)followed by layer 2 (L2) and layer 3 (L3) respectively It canbe concluded that internal curing by AAC-LWA obviouslyimproves the strength of concrete by providing extra inter-nal water resource for more possible C-S-H formation Inconjunction with minute and standard compressive strengththe optimum proportions of AAC-LWA replacement were in

the range of LWA20 to LWA40 Those mixture proportionsmainly achieved the superior strength from normal weightaggregate while the suitable amount AAC aggregate replace-ment provided extra amount of water for internal curing tothe cement paste(5) The development of AAC as a coarse aggregate

replacement in concrete is not only utilising unwanted wastesfrom industry (recycling of waste materials) but also buildingup a new knowledge of using LWA as an internal curing agentas well as the production of value-added lightweight concreteproducts

Conflicts of Interest

The authors declare that they have no conflicts of interest


References

[1] I-J Chiou K-SWang C-H Chen and Y-T Lin ldquoLightweightaggregate made from sewage sludge and incinerated ashrdquoWasteManagement vol 26 no 12 pp 1453ndash1461 2006

[2] S Zhao C Li M Zhao and X Zhang ldquoExperimental studyon autogenous and drying shrinkage of steel fiber reinforcedlightweight-aggregate concreterdquo Advances in Materials Scienceand Engineering vol 2016 Article ID 2589383 9 pages 2016

[3] P Lura M Wyrzykowski C Tang and E Lehmann ldquoInternalcuring with lightweight aggregate produced from biomass-derived wasterdquo Cement and Concrete Research vol 59 pp 24ndash33 2014

[4] B Akcay and M A Tasdemir ldquoOptimisation of using light-weight aggregates in mitigating autogenous deformation ofconcreterdquoConstruction and BuildingMaterials vol 23 no 1 pp353ndash363 2009

[5] ACI Committee 213 Guild for Structural Lightweight Aggre-gate Concrete American Concrete Institute Detroit MichiganMich USA 1999

[6] K M A Hossain S Ahmed and M Lachemi ldquoLightweightconcrete incorporating pumice based blended cement andaggregate Mechanical and durability characteristicsrdquoConstruc-tion and Building Materials vol 25 no 3 pp 1186ndash1195 2011

[7] D Sari and A G Pasamehmetoglu ldquoThe effects of gradationand admixture on the pumice lightweight aggregate concreterdquoCement and Concrete Research vol 35 no 5 pp 936ndash942 2005

[8] S Weber and HW Reinhardt ldquoNew generation of high perfor-mance concrete concrete with autogeneous curingrdquo AdvancedCement Based Materials vol 6 no 2 pp 59ndash68 1997

[9] T Y Lo H Z Cui and Z G Li ldquoInfluence of aggregate pre-wetting and fly ash on mechanical properties of lightweightconcreterdquoWaste Management vol 24 no 4 pp 333ndash338 2004

[10] W Yodsudjai Evaluation of strengths and choride ion diffusivityof minute regions in concrete using newly developed methods[PhD thesis] Tokyo Institute of Technology Japan 2003

[11] W C Tang P C Ryan H Z Cui and W Liao ldquoPropertiesof self-compacting concrete with recycled coarse aggregaterdquoAdvances inMaterials Science and Engineering vol 2016 ArticleID 2761294 2016

[12] M Singh and R Siddique ldquoEffect of coal bottom ash as partialreplacement of sand on workability and strength properties ofconcreterdquo Journal of Cleaner Production vol 112 pp 620ndash6302016

[13] I B Topcu and B Isikdag ldquoEffect of expanded perlite aggregateon the properties of lightweight concreterdquo Journal of MaterialsProcessing Technology vol 204 no 1-3 pp 34ndash38 2008

[14] P Wattanachai N Otsuki T Saito and R WongjeeraphatldquoInfluence of curing condition on the properties of mae mohfly ash mortar at surface and interiorrdquo in Proceedings of theProceeding of the 6th Regional Symposium on InfrastructureDevelopment Bangkok Thailand January 2009

[15] M Suzuki M Seddik Meddah and R Sato ldquoUse of porousceramic waste aggregates for internal curing of high-perform-ance concreterdquo Cement and Concrete Research vol 39 no 5 pp373ndash381 2009

[16] R Kasemchaisiri and S Tangtermsirikul ldquoA method to deter-mine water retainability of porous fine aggregate for design andquality control of fresh concreterdquo Construction and BuildingMaterials vol 21 no 6 pp 1322ndash1334 2007

Submit your manuscripts athttpswwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of



Figure 1 Scraps of AAC block production

for curing purpose inside the concretemixtures It has alreadybeen proved that internal curing can significantly enhancethe strength and reduce an autogenous shrinkage of the finalconcrete products [4 5] Any porous lightweight materialcan be used as an internal curing aggregate (eg vermiculiteperlite pumice scoria expanded shale expanded clay andcrushed-AAC wastes) [6 7] as they could absorb waterduring preparation and mixing and then gradually releasereserved water inside the mixtures during hardening process[8] Moreover the rough surface and coarse pore structureof those lightweight aggregates can also contribute to aninterlocking manner on transition zones between cementpaste and aggregate (interconnected surfaces) leading to animprovement in mechanical properties [9]

The main aim of this paper is to utilise available localAAC waste as a lightweight aggregate in concrete produc-tion which could allow converting industrial wastes intovalue-added products Lightweight and highly uniformlydistributed porosity are key characteristics of AAC that couldserve as an internal curing material to provide sufficientcuring condition for concrete constructionThe suitable sizesand optimum replacement percentage of AAC aggregatewere investigated as well as the final properties of fresh andhardened concrete during the internal curing approach

2 Materials and Preparations

Portland cementwas a commercial grade type Iwith a specificgravity of 315 Local river sand was used as a fine aggregatewith specific gravity and fineness modulus of 239 and 290respectively The moisture content of sand was 080 with abulk density of 1645 kgm3 Coarse aggregate was commer-cial grade gravel from local suppliers The specific gravitymoisture content and bulk density were 270 050 and1540 kgm3 respectively AAC wastes were collected fromPCC Autoclave Concrete Company Limited Chiang MaiThailand Its specific gravitywas 106with a dry-unitweight of360 kgm3 As-received AAC with a water absorption valueof 28 to 30 was crushed into a smaller size by a standardJaw crusher (Figure 2)

The gradation of AAC coarse aggregates was then anal-ysed by the US standard sieve analysis The effective coarsesize used in this study was between 3810158401015840 (95mm) and 3410158401015840

Table 1 Grading of crushed-AAC aggregates

Sieve size (mm) Percent retained on the sieve210158401015840 (5080) 131110158401015840 (2540) 9183410158401015840 (1905) 18221210158401015840 (1270) 20123810158401015840 (953) 11354 (475) 1114Pan 2867

Table 2 Mixture labels and descriptions

Label DescriptionNC Normal weight aggregate concreteLWA Lightweight aggregate







S4 Lightweight aggregate with mixed class size of110158401015840ndash3410158401015840 to 3410158401015840ndash1210158401015840 to 1210158401015840ndash3810158401015840 by 20 40 40

(190mm) which accounted for around 50 of the overallamount of AAC aggregates and has an average finenessmodulus of 720 (Table 1) It is noted that the majorityof effective AAC-LWA size values were 3410158401015840 1210158401015840 and3810158401015840 and the size classes (as indicated with S1 to S4) ofcoarse aggregates replacement were therefore employed inthe experiment Mixture labels and descriptions of concretemixtures including size classes of AAC-LWA are illustratedin Table 2

The coarse aggregate commercial grade and size distri-butions are in the comparison ofASTMC33with size number



0102030405060708090

100


LowerUpper

NWCA

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()








S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(a)

S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(b)


0102030405060708090

100

S1S2S3

S4LowerUpper

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(c)





Coarseaggregate

ACCaggregate


LWA20

20 S1 571 200 588 750 4620 S2 571 200 588 750 4620 S3 571 200 588 750 4620 S4 571 200 588 750 46

LWA40

40 S1 571 200 588 563 9340 S2 571 200 588 563 9340 S3 571 200 588 563 9340 S4 571 200 588 563 93

LWA60

60 S1 571 200 588 375 13960 S2 571 200 588 375 13960 S3 571 200 588 375 13960 S4 571 200 588 375 139


Exteriorzone

150mm

150mm

zoneInterior

15 mm












Exterior zone

Exterior zone

150mm

Interior zone


15 mm

15 mm

LWA LWA 1 2 31 2 3


prism


3mm

3mm


0

5

10

15


Slum

p (c

m)






0

10

20

30

40

50

60

70

80

Flow

()










NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)










100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of




0102030405060708090

100


LowerUpper

NWCA

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()








S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(a)

S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(b)


0102030405060708090

100

S1S2S3

S4LowerUpper

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(c)





Coarseaggregate

ACCaggregate


LWA20

20 S1 571 200 588 750 4620 S2 571 200 588 750 4620 S3 571 200 588 750 4620 S4 571 200 588 750 46

LWA40

40 S1 571 200 588 563 9340 S2 571 200 588 563 9340 S3 571 200 588 563 9340 S4 571 200 588 563 93

LWA60

60 S1 571 200 588 375 13960 S2 571 200 588 375 13960 S3 571 200 588 375 13960 S4 571 200 588 375 139


Exteriorzone

150mm

150mm

zoneInterior

15 mm












Exterior zone

Exterior zone

150mm

Interior zone


15 mm

15 mm

LWA LWA 1 2 31 2 3


prism


3mm

3mm


0

5

10

15


Slum

p (c

m)






0

10

20

30

40

50

60

70

80

Flow

()










NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)










100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(a)

S1S2S3

S4LowerUpper


0102030405060708090

100

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(b)


0102030405060708090

100

S1S2S3

S4LowerUpper

Cum

ulat

ive w

ater

reta

ined

on

the s

ieve

()

(c)





Coarseaggregate

ACCaggregate


LWA20

20 S1 571 200 588 750 4620 S2 571 200 588 750 4620 S3 571 200 588 750 4620 S4 571 200 588 750 46

LWA40

40 S1 571 200 588 563 9340 S2 571 200 588 563 9340 S3 571 200 588 563 9340 S4 571 200 588 563 93

LWA60

60 S1 571 200 588 375 13960 S2 571 200 588 375 13960 S3 571 200 588 375 13960 S4 571 200 588 375 139


Exteriorzone

150mm

150mm

zoneInterior

15 mm












Exterior zone

Exterior zone

150mm

Interior zone


15 mm

15 mm

LWA LWA 1 2 31 2 3


prism


3mm

3mm


0

5

10

15


Slum

p (c

m)






0

10

20

30

40

50

60

70

80

Flow

()










NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)










100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



Exteriorzone

150mm

150mm

zoneInterior

15 mm












Exterior zone

Exterior zone

150mm

Interior zone


15 mm

15 mm

LWA LWA 1 2 31 2 3


prism


3mm

3mm


0

5

10

15


Slum

p (c

m)






0

10

20

30

40

50

60

70

80

Flow

()










NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)










100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



Exterior zone

Exterior zone

150mm

Interior zone


15 mm

15 mm

LWA LWA 1 2 31 2 3


prism


3mm

3mm


0

5

10

15


Slum

p (c

m)






0

10

20

30

40

50

60

70

80

Flow

()










NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)










100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of






NC 064 084 3175 095 130 3678 077 121 5722 103 154 4948LWA20 083 112 3400 112 169 5110 111 148 3333 141 201 4208LWA40 093 100 724 130 155 1955 126 132 473 157 173 1059LWA60 093 113 2137 123 162 3142 115 143 2506 139 180 2904

0

500

1000

1500

2000

2500

3000




Den

sity

(kgＧ

3)










100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



100

150

200

250

300

350

400

450

0 7 14 21 28




Testing age (days)

Com

pres

sive s

treng

th (M

Pa)


100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)








100

150

200

250

300

350

400

450

Com

pres

sive s

treng

th (M

Pa)






Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



Cement paste

ACC -LWA

ITZ

Cement paste

NWCA

ITZ (on surface)





NC 064 095 4847 084 130 5413 077 103 3448 121 154 2786LWA20 083 112 3400 112 169 5110 111 141 2698 148 201 3532LWA40 093 130 3903 100 155 5499 126 157 2382 132 173 3074LWA60 093 123 3200 113 162 4293 115 139 2164 143 180 2551


Mixtures

Air curing (AC)

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d


000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)



5 Conclusions





Mixtures

L1 7 dL2 7 dL3 7 d

L1 28 dL2 28 dL3 28 d

000

050

100

150

200

250

Com

pres

sive s

treng

th (M

Pa)





000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



000

050

100

150

200

250

300


Min

ute s

treng

th (M

Pa)

Mixtures


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)


(b)


000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)



L1 7 dL1 28 d

Std 7 dStd 28 d

000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(a)

000

050

100

150

200

250

300

Min

ute s

treng

th (M

Pa)


L1 7 dL1 28 d

Std 7 dStd 28 d


000

1000

2000

3000

4000

5000

Stan

dard

stre

ngth

(MPa

)

(b)









References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of



References
























CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of









CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


properties and internal curing of concrete containing...

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