Propertier of Alkali-Activated

B.P.S. P-Cement as Binder

in Concrete

SvnoDsis: F cwnt is a binder for concrete which use ground granulated blast-fur-nace slag activated with and alkaline admixture. The activation method is notnew. but only seldom used in practice. The combination of chemicals used in Fcement can be modified to give concrete its desired properties.

’ F concrete has given very satisfactory results in test performed siece 1979.F concrete tix is highly wrksble. even if its water-cement ratio is la. Typicslw a t e r t o c - t r a t i o s a r e b e t - 0.25... 0.35 and the mix is mre thixotropicthan a clinker-based concrete rix. Strength development properties are suitablefor curing at elevated tmperatures and 24 hour strength, as a rule, exceeds 40MPa when heat treatment is used.

One of the must useful properties of F caeent is its good sulphate resistance.In the use of F cement low heat of hydration, accurate control of workabilityand curing temperature require special attention.

kwords: Alkali-activeted, blast furnace slag. ground granulated alkaline adsix-tun, workability, water cement ratios, thixotropic. heat curing, strength develop-mat.

PROPIEOMKS DE LI ESCORIA DE ALTO HORWO LCliYIOACOW ALcnl.1 (CUKWO f) cm CEIIEIITAWLE N E L COWXTO.

tieikNi Nukko y Rirtro Iknnonon

RESUHEN~d El cemeato F es un cementante para coacreto, el cual em&aescorfa dk alto horn0 finementc mlida y activada coa ua aditivo alcali-0 0 . El dtodo de activacib ao es nuevo, pero eolemeate es apleadoram vaz en la pr&ctica. la combinecidn de sustaecias qufmicas utiliza-das en el cement0 F se pueden modificar pars derle al cancreto larpropiedades deseadas.

El concrete F ha dado resu l tados muy aatisfactorios ea 10s eneayeaefectuados desde 1979. Le mezcla de coacreto F es altamente tiebajeblesun s i su relacih sgm-c-to e s b8ja. las relaci- qpa-aemtotfpicas es& eatre 0.25 y 0.35 J l a mescla cs a&s tixotrdpiu queuna mezcla de concrete a base de clinker. Las propiedadee de deserroilode resistencia son adscuades para e l curado a teqeraturas elevadnsJ l a reeisteecia a lae 24 horaa, cao regla. excede d e 40 !iPa coandose emplea un trataedento t&&co.

UM de las propiedades ds 6tiles de1 rerento F es so bueaa resisteociaa 10s sulfatos. Pa el eopleo de ao cemento P de hajo calor de hidrata-ci6n se requlere une atencibn especial sobre el control de la msnejabi-lidad, F.PB terperatura de curedo.

Palabraa clave: Alceli ibn activado, eecoria de alto horno molidagranulada, adltiro alcaliao, maoejabilidad. reIacioaes agua-ceeento.tixotrbpice, U&C. curadi, deserrollo de reaiateecia.

* .

162

PROPRIETES DU L A I T I E R D E IIAUT FOURNEAUA C T I V E P A R ALCALIS ( C I M E N T F).COMMBLIANT D A N S L E BETON.

Heikkl Kukko, R tstro Madnanbn

164 Jbkko and Manaonen

&fkkf -40 is e senfor research scfentfst in C~8~nt.e bed Slll~rte Leboratory,Technfcal Resew& Centre of Ffnland sfoce 1975. He is in charga of the sectionfor concrete materials on productfon technology. He has been Involved fn variousresearch projects COnCeMfng concrete mteI'fa?s md their USC.

INlROOUC11OW

Blended cements containing Portland cllnkn and blest furnace sly afewidely used as e bfnder In concrete. Slag content Is usually up to 00 S. fflendedcesmts ad super-sulphated cement are used expeclally in structures exposed tosulphate attack md In massive structures, In *hfch low heat of )(ydratim Isbeoeficirl.

Blest furwc slag. a by-Product of the stnl iadustrj, Is ~ouer-pricedthan Portlend Bt, even If It is usually ground to l higher spccfflc weathan Portland clfnkcr. The strength galn of blended cemsnts and super-sulPhatedcement fs lower than that of Portland cement. Therefore many lnvestfgatfoos havebeen coo&cted to study the possfbilfty of accelerating the strength Qvelopwotof slag using SQC other activators than Portland clinker (or Ca(OH)2) and gyp-sum. Chemical actfvators frequently used are CaC17 or strong alkalfes. e.g.NaOtl, +COg and waterglass.

Slag-alkalf-cemets have been patented expecially in the 1970% fr almostten countries, but Oparmtly they are fndustr~ally used mly in the SovietUnion and Polrad (4). In the viet Unfon the Jaunt prmWed In 1964-1982 ismentfooed to be overl5OOfXxl concrete. Alkali-activated slags have beenstudied since the 1940's and activation is cagnly used in testfng of slag.

F-concrete fs based on blast furnace slag, which is activated with a com-bfnation of chemfcals galled F-a&tfxture (1). Portland clinker is not used. F-cement has good strength development propertfes and the workabflfty of F-con-crete mfx is high. The main constituents of the rdmixtum are alkaline actf-vators. plastfcfsfng coqwwnt and minor amounts of chemfcals for regulatingsettfng and fwdening as well as the air content of the mfx.

Plasticizing amd water-reducfng caponent in F4Mxtul*, l lfgno-sul-phonate product. ensures the dispersfon of the hserterfalef the bfnder andis an iqartant factor in dfmfnlshfng the void content of the F-concrete. Theair-entraining effect of lignosulphonates can be reduo8d. when ncessary. usingan anti-foaafng agent. The F-admixture Is a mixture of several coeponents andIts colrposition can be adfffed In conformity to the properties of basfc ma-terial and demands set on the concrete (1. 5).

Tkr investigatfom on the F-cement began In Finland in 1979. Precastelement production tests have keen performed fn severe1 precrst factories. andin the au*mm I#12 a storage bufldfng uas constructed for which F-concrete waspartly used. The industral use of F-concrete is planned to expand gradually inFfnland.

CONSTITUENTS OF F-CONCRETE

As previously mentfoned, the F-cement consfsts of two components, basfcmaterial and admfxture. In prfncfplc. varfous silicate Iraterlals could be usedas a basic material. I practice almost every test In the Concrete and SflicateLaboratory.uas made using blast furnace slag, fn whfch the CaU/Sl02-ratio fsclearly lower than that of Portland clfnker. It also seems possfble to use flyash as part of the basfc material. The alkalinity of Ffnnlsh blast furnace slagsis relatively low as shown In Table 1.

The slag of Rautaruukkl Oy, the CaO/SlO -ratfo and activity of which Inblended cements 1s Tower than that of Ovako s ag.? has fn the tests with F-concrete given hlgher strength results.

Slag Is usually ground to the speclffc area of 450 - 500 q */kg (Blafne).In the first place ffneness affects the rate-of strength developrrnt. When thefineness increases ear&v strength results also rise clearly at least to thespecific area of 700 m /kg. A rapid granulation and a glassy structure arefmportant from the activatlco point of view.

The F-admixture may be used as a powder or. usually, as a solution inwater. The amount of dry admixture Is about 5 to B per cent of the amount ofbasic material. F-admixture Is alkaline, which Is to be taken into account whenhandling ft.

Normal aggregates are used In the F-concrete. Tk normal preliminary testsare necessary and sufficient for selecting the gradfng and ascertain9 the properamount of water.

PROPERTIES OF FRESH F-CONCRETE

As stated above. the F-concrete contains superplasticizer, which fs usedto lower the water-cement ratio. If the admfxture Is added In a water solution.then most of the water fs added with a&$xture because of the low total watercontent of the mix.

Fluid consistency has been used in most tests, but also stifferconsfstencles are possible. Because of the small amount of water needed in themfx, small changes in w/c have a strong effect on workability.

The propertfes of a superplastfclzed nix differ to soma degree fromsuperplasticfzed Portland cement concrete. The F-concrete fs thfxotroplc. In theflow test the concrete cone settles rather slowly and spreading continues for alonger time than that of Portland cement mix. A F-concrete mix of plasticconsistency is somewhat stfcky. but on the other hand easy to canpact.

Hater-cement ratio Is In a fluid nfx about 0.3 and In a vary stiff *ixabout 0.2. The afr content of a superplasticized dx Is low. ranging fra about0.5 to 1 2. Becauje of the lini afr content. the denslv of the mix Is In theorder of 2.5 kg/dm , and pN of the mix about 14.

166 K u k k o a n d Manoonen

COMPRESSIVE STRENGTH

The strength development of F-concrete Is barfcally dependent on the samefactors as that of ordfnary Pot-land cement concrete (OPCI I.e. on the water/cement r&lo. the cement content and the temperature.

Yhen tuo mfxes of the same proportfonr are coapared (e.g. In Table 21..thenix contafnfng F-cement gives higher strengths at 7 and.22 day& than that ufthOPC. As can be noted, the workabflftfes dfffer consfderably betueen the mfxes.Usually In practfce uorkabflftfes are the sam and rfth the same cement contentthe water-cement ratio of the F-cement content Is consfderably lower. In thcase the dffference in strengths is slfghtly hfgher than that in Tabl&J.

Yith the sane workabilffy and the cement content of 300 - 400 kg/m3 thestrength of F-concrete Is at 20 days about 20 to 40 Z hfghet than that&fFfnnfsh OPC concrete (look at Tables 3 and 4).

kg/m!The tests have been usually performed with the cement content of 306 - 400The effect of cement content in heat-treated mortars Is shcun fn Ffg. 1.

In the case of F-concretes the effect of temperature on the strength gafnis becomfng nore pronounced than in the case of OPC concrete (Fig. 2). Inpractice this, in most cases, leads to heating of the concrete sfnce the heat ofhydration is low. A temperature of about 40 % or higher Is needed fn practfcefor precast element productfon. As is shoun fn Ffg. 2. the F-concrete alsohardens at temperatures below +20 'C. but strength developmnt begfns ffrst e.g.after curing at 5 OC for 3 to 5 days. On the other hand, hfgh temperatures canbe used succesfully in heat treatment. In the'laboratory tests hot mortar (50 -63 'Cl has also been used in order to achfeve hfgh strengths in a feu hours't ime .

The exact shape of the strength development curve also depends on thechosen proportions of F-admfxture. the fineness of the slag and its chemfcalcomposftfon.

The laboratory tests on F-cement were started In 1979 and there are long-term strength results obtained durfng two years. The strength fs fncreasfng allalong thfs perfod. uhfch can be seen from the comparfson results in Table 4.Similar results obtafned from two years' concrete tests are presented InFig. '1.

The ratio of flexural to compressfve strength seems to be equal or alittle higher for F-concrete than for OPC-concrete. The flexural strength ofusually from l/7 to l/10 of the compressive strength.

In this connection it might be necessary to mention that therr is a needfor proper moisture control-where curing. 4n uiequal evaporation leads to unevencolour on the concrete surface due to the colour of admixture. When necessary,the blemishes on the surface can be washed off. A surface cast dgnfnrt an afr-tight surface may be of greenish colour. This tinge disappears howrvw In d fewweeks time in aft-. as it does in the case of ble-4ed cement rich itr \ldq.

Alkali-Activated 167

DEFORMATION PROPERTIES

Shrink%

Comparing the mixes presented in Table 2, there seems to be no significantdifference in the shrinkages (Fig. 4).

Another series of tests was also performed, in which the concretesindicated in Table 3 were used. The main idsa of these tests was to compare F-and OPC concretes with each other having the same cement content and workability(tests 1 and 2) and, on the other hand, the concrntes having the same strengthand workability (tests 2 and 3). When comparing the results of these test,presented also in Fig. 4, the shrinkage-decreasing effect of the low w/c-ratioof the mix can be seen. Shrinkage of OPC-concrete 2 is clearly stronger thanthat of OPC concrete in the previous test due to the higher amount of water andearlier drying. The shrinkage of F-concrete 1, shown in Table 3, is lwer thanthat of OPC concrete 2 with the same workability and strength. If the cementcontent and workability are the same, the difference in shrinkage results stillincreases.

Modulus of elasticity

The values of modulus of elasticity seem to be close to those calculatedin accordance with formula E = 5000 Jfc, where fc is the compressive strengthdetermined on the 15 cm cubes. The measured values of concretes shown in Table 2were 34400 MPa (F-concrete) and 35800 MPa IOPC-concrete).

Creep

Creep tests have been made using the mix proportions mentfoned in Table 3.Test specimens used are, as in ail deformation tests, cylinders 6 134 ma x 370nm.The ages of the specimens at loading were 7 and 28 days and the load used was

40 % of the compressive strength of the specfmens. The creep coefficients(i.e. ratio of creep to elastic strain) are presented in Figure 5. The testresults obtained from the first tests indicate that the rate of the creep variesin the case of these two concretes. At the beginning, the creeo coefficients areclose to each other, but the F-concrete creeps longer.

SULPHATE RESISTANCE

The tests were performed as comparison tests on concrete using F-cement asa binding agent and ordinary Portland cement. as well as sulphate resistingcement (30 % Portland cement plus 70 % blast-furnace slag) as comparisonbinders. The quantity of the binding agents used in all tests was 40D kg/m3. OfF-cement as a binding agent two series of test were made: one at a temperatureof 20 OC and the other at 70 'C. The time of heat treatment at a temperature of'0 'C was ? hours. Water was added to mortars until the consistencies in allcases were equal. Water-cement ratio for ordinary Portland cement and forsulphate resisting cement was 0.54 and for F-cement 0.39.

168 Kukko and Maaaoncn

After casting l ech spec4a~uss awed et 160 I ml and at 20 oc for 37&ys.Shwquentto thls the testsppcclmns mm awed to and cumdln thefollwlng solutions: water, 1 t Ilgsb4. 10 t ftg664. 1 'IL hS2gO4 and 10 g ba2604.

Cagmsslw stmnP

and tensile strengths (in beodly) wem detemlnedafter 37 days from wst ng. The saw deterdnrtlom wm also perfomed onspecirns cured for 6 months, I2 months and 25 nmths In dlfferent solutions.

Table 4 shws tRe mwlts ef capmsslen stmngth values end Table 5 shewsthe msults of tensllc stmngth (1~ bending) nlubs on alng different Mndlngagents after 6 months. 12 months end 26 months.

After 12 months’ curing In l 10 S RgSO -solutla all the suecirns wembroken so badly the testing was llposslblc. 1 fter 26 nseths curing In a 10 %Na220

?-solution It could be. noted that the rpwlmns wde fw WdlMw Portland

cemn were also destroyed.

The developaentof capmsrioo strength of F-cemnts cured In a 1%Na2W

t-solution was slightly greater than that of ordlnav Portland cernt and

cemn blended ulth blast-furnace slag. Mffemnce betueen coapresslon strengthsof the testspecimns uds fromF-cemnts and the reference specimm asds fromordfnary Portland cemnt and blended cement cumd In a 1 t WgSO4-solution anda 10 t Ns2X14-selutlon was very clear.

Flgum 6shons ths devolopmnt of canpmsslw strengths of each speclmncumd In a 10 t ha 50

? il-solution. After 25 mnth's curing the test spcclrns mds

fromordInary Port an cemntuam dsstroyed;the ~stspecimns mde franblended cemnt had 18 t louer corpmsslve stmngths thsn ths specimns cured 1water; the testspeclaens msds fron F-cemntrlthoutheattmatmnt hsd 5 Xhigher and those treated with heat 10 t higher cagmsslve strength than thespeclms cured ln water.

Tendsnu fRr tmsila stmngms wl bmufll#~ Do develop was qua1 ‘t# tkdevelmntof coqmsslon stmngths btnot equally abvtous.

As F-cennt Is l ctfvated rfth various chmtcals and these chnicalScontain sodfu~ coqonnds, it wss considemd necessary to stuQ the alkalim&Ion sensltlvlty of F-cemnt c-red with the Flnnlsb ordlnav Portlandcement S 40/b.

7he lnvestlgatlm was mads as a cqrrlsoe test an concradr vertor. lheaggre ters standwd sand In coqlfanceuith DID 1184. uld the maetinsister al used was gcltana opal originating in tha Soroms dlstrlct. Callfomla,rU.S.A.

Alkali conWet of binding material uas determiosd prior to tcntfng. fhlsCresults am shorn In Table 6.

The test rrmngemmts cogllod as f8r es applicable with thf! ASlD C 227-71mthod. Ssm practical changes acre mda In the ~tRod but, In the min. Itmlndad unchanged. The masuremnt squfpcnt and muulds ccllplled ~11th ASlD CMD- 71.lhecosposltion of themrtarrsl partcemt/ Z.tsprrtrmd;water vas addad until thn conslstcncy of the mix was suitable. Yatermntratlo for ordinary Portland cement ws 0.48 and for F-cent 0.27. D/ten 24 hoursold tk speclmem uem demaulded and measured with an accuraQl of 0.002 II.Aft& thu seasunrrnts the prisms were aved to and kept In curingconditions.uhicbwwe T = 40 + 2% and WI B Mg. In eapllancc uith NlD C 227. Ihcffncst part of the-aggiwgata was replaced rith 3 5. 8 S and 15 t oprl Weltamwrrry).

lha changeslnlength maawmnnts sharvd thattha incmslilg sodiumconcentration in the blast furnace slag-based binding a nt stmngthcns alkalireaction sensltivfty. It Is to be observed that If thu a La11 content lncrerses9"the mount of the reacting stone material has also to Increase so that fhereaction would becw stronger. A sull amount of reactlvs material does notcause cxpanslon teactlon If tha alkali content Is hlgb, and Partly vice verse.

InUI1trrtrrbart2.DSsodludU*infgMotthrblndlnJr~cwldbe rdded to the blast funwe slag kefa~ the sue level of alkali raactfrf~was reached as In the case of thu ordlnaby Portland cemaet. The alkall contentof Portland cement and slag we presented In Table 6. Thus the alkall rrrctlrlt#of F-cementcontalninga tv~ical dosagnofF-a&sixter, is cut greaterthae thatof odnary Portland cemsnt. Saa results of alkali rrrctlvity rrhm eslng atyplcal dosaga of F-admixtura (ila-content 1.6 1 of slag a#mt) as compared rfththe alkali reactlvlty of ordlnaw Portland cemmt am shoun In Flg. 7.

PREVENTIW OF STEEL cmRos!oH

Stnlc~roslonUstwrsIrb~eaqrr(ng~stnlcorrorl#lIn~~tspeclms mda fra ordinary Portland cement md fra blast-furnace drgactivated with F-atixture. Tkc test specirns wera cyllndars, 4.4 a Indlamster and 16 cm In holgbt with a&edded 18 ssn steel bar. lhe rxlumparticle size of tha aggregate for concrete MS 8 an. The dsvas visually estlnted. To both mrtan water ms added untl coeslstencles ware0

m of corrosion

cgual Yder-cement ratio was 0.64 uhen using ordinal Portland cement and 0 3)when ;sfng F-cement. The amount of binding agant was In both series rOa ko/l5.When cured 28 days in 100 t RH test rpccfmm mra dcrfded Into thm lots. Onupart was contlnously kept In 100 X RH, the second part was moved into sballatap rter puol and the third lot Into shallow l rtlflcal sea-water Pool.

1 7 0 Kukko and Maaaontn

Tcclpcraturc was in all cases 26 Oc. Artifical sea-water was mda b dxiog Utefolloulng cenicals:

?g/l NaCl

2.41.2

Corrosion developmaat was investigated after 3 months. 6 maths rod 1 yewby splitting four speclmns of both series cured in every three conditions.Oeveloprnt of compresslm strengths under the sama conditions was alsoInvestfgated.

After OM year curing differences betueee cormslen of reinforcing steelin concrete amde from Finish ordinary Portland cement and fra Fa couldnot be observed. Both series were in all cases c~lctely fm fm corrosion.

Bevelopamntof coqfressfvc strengthr ofwtrn used are sitam inTable 7.

FROST RESISTANCE

Freezing-and-thawing tests have been perfwrd using Fsomrete withoutair entrafnrnt. As stated above, the air content of a F-concrete xix is low.uhfch results in a lw permeability to water. hi example of the results of F-concrete is oiven in Tables B and 9.

As shown. the cap~ssive strength lncrwsed Crfng tJbe freezing l dthawing cycles. The rount of the pores. lrhich art-air-filled after ilcrslon inaWpherfc pmsure,was rawredand ituas 9gef the tetel pon ceThis so-called protective pore ratio Is la sod world ~11~ lead to frostdamage. The reason for absence of frost damage in this and other siailar testssay be the la total porosity, fnpenmabilfty and relatively hi* strength ofthe Cemnt NitriX. BifferMCe in pore StNCtUN of F-concrete and @%WfICfV~canbe seen inFlg,&a&PI

PRBPERTIES Al NIBI TEWERANRES

The soeclal features of F-cemant: water l x~lsion at ahout 20 % lower*rature than BBC fmar the boiling te+rature of water. absence Ofoortlandlte and Its dehvdratlon at about 500 '% end the hi& content of f%(I)influence significantly~its behaviour at high temperaturesI The effect ofhigh temperatures does not seaa to be as datrfmental to F-concrete than to WC-concrete (4 , 6) and the teoperature of use reaches higher.

1. Forss. 1.. F-cemwt, a lar porosity slag met for the precastfngindustry. Iet. confemnce on sleg and blended ceaerts. Feb. 12-19.1982 University of Alabane. Biminghaa ¶ p., l pg.

2. Purdon, LO. The actfa of alkalies on blarthrmrco slag. 4. Sot.Chem. In&. Sept. 1940, p. 191.

3. ;u;hovskij. VA. A1kalischlackenbeten. I)aurteffindurtrie 1974 B.3.. - 13.

4. 6luchevskij. V.D., Krivenko. P.V. 1 Rumova. R.F. Physico-cheaicalfundamentals of condarning ef rlneml dirpersiom. Kfev 1983. 15 p.

5. Kukko. H.. Uannonen, R.. Ckeafcal ad rchanical propwtia ofalkali-rctivated blast furnace slag (F-concmte) in: Rcdfc ConcmteResearch. The Nordic Concrete Federation. Publicatioe Re 1. 0~101982. p. 16.1...16.16.

6. Jumppanen. U.N., Diedwicks, V., Effects of high tearperature 011 theticrestructure and manical behaviour of F-cencrete. Techn. Res.Centre of Finland. Fire Technol~ Laboratory. Publicrtfon (underpreparation).

Heikki Kukko

Kukko and Maaaonen

Table 1 Typical values of chemical ColpOSitiOn ofFlnnlsh blast furnace slags.

Table 2 Prope*ties of F-concrete. Mixes 1 and 2.

mix 1 nix2

type of cementk g/m3

F-cement OPCcement 383cement: aggregate: water 1:?0.30 1:5:0.38

S?U!!Tp Gill 2GVebe set 0 2:air content xtensity i g/Cc3 :::6 :::3

compr.strength MPa

2: :-

4 5 . 0 36.05 1 . 0 45.5

Table 3 Properties of F-concrete and OPC-concrete used indeformation tests.

test number ‘ 1 1cement type F-cewnt Ok

cement:aggregate:water 1:4.7:0.31 1:5.1:0.52planned cement content kg/m3

kg/m3 iii400

calculated cement 3 9 3content

’ 3F-ccarnt

1:6.2:0.4,

i4

consistency: slum0 cmVebe setflow toIn) cm

air content 4density k3/dra3

compyyi ve strength MPa

20 d

1 5 85.0 1 . 9

4 2 -

:::7 ::$

44.0 2 5 . 555.0 32.0

145.8

38

0.02 . 4 5

2 4 . 037.0

2

Table 4 Compressive stengths of concretes. Haxirmm partfcle size of the aggregate for concrete was 8 asn.

Compressive strength (HPaI

6 months 12 months 25 monthsBinding agent start.

1% 1 0 % 1 % 10 x 1% 1 0 % 1% 10 :, 1% 1 0 2 12 10 %37 d If20 MgS04 WgSO4 Na2Sll4 Na2$34 H20 MgSO4 MgSO4 Na2S04 Na2S04 Ii20 HgSO4 MgSO4 Na2S04 Na2S04

Ordinary Portland 50.6 54.7 51.6 40.6 50.6 50,5 54.4 44.2 - 58.3 3 8 . 5 5 6 . 4 4 1 . 2 - 5 9 . 9 -cementCement blended of 38.8 66.8 5 2 . 7 3 6 . 5 6 1 . 6 5 0 . 3 66;6 5 4 . 2 - 6 8 . 5 5 8 . 0 7 0 . 5 5 4 . 7 - 68.6 5 7 . 9blast furnaceslagF-cement 20% 5 6 . 8 7 5 . 3 7 4 . 6 40.9 7 4 . 6 7 6 . 4 7 3 . 4 7 5 . 4 - 7 6 . 4 7 9 . 1 7 7 . 9 77.b - 83.6 8 1 . 6F-cement ?O°C 5 3 . 9 6 8 . 2 67.0 3 3 . 3 69.9 6 7 . 4 63.2 7 3 . 3 - 6 7 . 0 7 3 . 3 7 2 . 9 7 6 . 7 - 7 9 . 6 80.3

Table 5 Tensile strengths of concretes. Waxfmum particle size of the aggregate for concrete was E II)).

1

Binding agent

blast-furnace

Tensile strengths (PlPaI

6 months 12 months . 25 months

1% 102 1% 10 I 1% 10% 1% A0 x 1% 10% 1% 10 aIi20 MgSO4 MgSO4 NapSO4 Na2S04 H20 f4gSO4 figSO N&$04 LpSOq H20 MpsO4 MgSO4 W12u)4 Na$$

0.1 9.4 0.5 9.8 0.1 0.7 4.7 - 9.4 3.6 8.9 6.2 - P O . 4 -

9.4 8.9 5.3 10.3 9.7 9.2 9.6 - 9.8 9.9 1 0 . 1 9.5 - 1 1 . 5 9.7

9.7 9.5 8.0 8.6 1 0 . 0 9.1 9.6 - 9.8 1 0 . 4 9.9 1 0 . 4 - 9.9 1 0 . 81 0 . 7 1 1 . 2 8.0 10.2 1 1 . 1 9.1 1 0 . 3 - 9.5 1 1 . 1 1 0 . 9 1 1 . 8 - 1l.I 1 1 . 1

rIbI@ ? *vc1opant cf C~rcSSive strongtbs tr steelcorrosion test.

Environ- 9tnccr cwresstrr Strength tW4mnt

3u0wlsl6oontbsl1yoor

O*aimrf Portland 53.7 #.? 57.9

.73.6 79.0 79.6

46.9 66.6 43.7

75.4 77.0 99.7

Tdt!lC 8 Properties cf F-rrwvte used Infrost reristrnce test.

wrtcr/rggregde'/cment 1 ,: 4.5 : 0.39

dr content 1.0 8

rolomrCn stnngth 3 e 26.dWaI d 40.5 nr

2fi.d .W.O HPI

cwlpres51 ve Flrrsralstrength MPa strength EIPa

- tested rt the bgirdsgof Creezfng m thrhlrlg

- tested at *the end offwxlng and thadng

uater wrfng 28 d + 1OCcycles of freezing (-29OCIn air) 4nU Vmwlng f*2C°Cvator)

44.0 5.3

55.0 ?.A

54.0 .5.5

Y./i- x

200 kQlm' bb

L0 5 e :2 :a 72 166 t(h) 6%

‘ig. 1 Stres;th of mwtrrs rh*.?ifferent F-cement content.Heat treament Soi 3 Tours.sire or ag3reptes I w.

Mastic consfrttncy. Rarinu

iz 3 3

2 0

10

0h 1 3 7 28 Age. d

r-1

Fig. 2 Strength development of F-concrete rt differenttemperatures.

--e c u r e d i n wotef’ i 2 0 %--I RHlOO% 72O'C

--o R H 4 0 % f20’C

I t

3 0 h 2 8 dI I f -

6m ly 2~T i m e (lg-stole)

Fig. 3 Strength development of F-concrete testspecimens In a Wo-year test.

Ftg. 4 Shrlnkage results of test concretesCuring: fn 40 X RH after 28 d (mixes of Table 2)

in 40 X RH after 7 d (mixes of Table 3)

. . , . . . F 71 f. . .. (F-cem, loading oge 7d, mix 1 1$ 6.0- - - - F- P7 28/l . . . . ,/

$S,O- -P285 -.-.- F 28/2

: 4.0-

I 2 3 4 5 10 20 30 50 100 200 '40060 xx)

Ttme of loading IdayS)

fig. 5 Results of creep tests of concretes presentedin Table 3.

IO-'.

I I I3 6 12 1 imc. months 25

(j!iet

Binding agent0 Ordinary Portland cement (w/c = 0.54).CL Cement blended with blast-furnace slag (w/c = 0.54)o F-cementx F-cement, heat treatment at 70 'C (w/c = 0.39)

Fig, 6 Compressive strengths of concretes cured in a 10 X Na2SO4solution. Maximum particle size of the aggregate forconcrete was 8 axaandcement quantity 400 kq/m3.

0.3

0.2

A 3Xopalx 8Xopalcl 15 U opal- OPC- - F-ccmcnr

./ ’

)C,LL.------.-

-A---A-

30 50 70Ttme. d

Fig. 7 Results of alkali reactlvlty tests. Activation of slag with1.6 % Na.

Fig. a Di fferentlal pore size distribution of heated F-concrete

Fig. 9 Differential pore size distribution of heated normalconcrete made with OPC.