Fracture energy of high performance mortar subjected to high temperature

Transcription

1 Fratur Mhani Conrt Conrt Strutur - Rnt Advan in Fratur Mhani Conrt - B. H. Oh, t al.(d) 2 Kora Conrt Intitut, Soul, ISBN Fratur nrgy high prforman mortar ubjtd high tmpratur S. Djaknoun E. Oudraogo Domain Univritair, BP 53, 384 Grnobl CEDEX 9, Fran. A. Ahmd Bnyahia Laborair d Méaniqu Avané (LMA), FGMGP d L USTHB, BP 32 El-Alia, 6 Algr, Algria. ABSTRACT: A thr-point bnding tt apparatu for tting onrt-lik matrial at high tmpratur ha bn dvlopd. Nod pimn r hatd at a rat 3.3 C pr minut variou tmpratur, up a maximum 9 C. Thy r n ubjtd a thr-point bnding tt hil tmpratur a hld ontant. Th maximum pak load ourrd in tmpratur rang 3 5 C, drad harply at highr tmpratur. Th xprimntal rult dmontratd a notiabl nonlinar fft tmpratur on fratur ritan mortar for high prforman onrt. Tnaity paramtr uh a tr intnity far or fratur nrgy r found volv ith tting tmpratur. Tmpratur in rang 3 5 C ld optimal valu for paramtr, hra at highr tmpratur, paramtr valu drad onidrably. SEM mirograph hatd pimn aftr mhanial tt failitatd undrting maroopi bhaviour. INTRODUCTION Conrt i a htrognou matrial ith quaifragil bhaviour. Th miro-raking pro an altr mhanial proprti onrt. Strdformation urv in onrt initially undrgo a linar lati volution n a nonlinar volution up tr pak, follod by a mor or l vr tning pha. Th oaln miro-rak lad apparan a fratur maro-rak. In many a, thi fratur i not only du rak propagation mhanim. Miroraking an b dividd in pha; firt pha bgin ith rak propagation throughout initiatd miro-rak. Th ond pha i ubjt fratur mhani. For onrt matrial, miro-rak ar ontitutiv matrial, i.., y xit prior appliation a mhanial load. Th onubtantial miro-rak an potntially or ntially ontribut maro-rak formation lading matrial failur. Th ory lati linar fratur mhani i urrntly ud analyz mtalli matrial failur. All damag phnomna ar aumd our at tip rak. Convrly, nonlinar fratur mhani aum xitn a fratur pro zon (FPZ), a plan zon hr damag mhanim our. Thi lat approah appar b mor rlvant analyi iotropi matrial ith quai-brittl bhaviour, uh a onrt, in hih mod I fratur i dominant. Similar nonlinar fratur mhani, damag mhani ha bn dvlopd modl fratur matrial hil xhibiting tning bhaviour; thu, it i rlvant modlling rak initiation pha. Many tudi hav rportd an influn mortar or onrt ompoition on it ritan rak propagation (Kaplan 96, Gjorv t al. 977), but rult hav bn ontradiry. Morovr, a id varity tt tmpratur rang, xprimntal ondition, matrial ompoition, ur ondition mak it vry diffiult ompar publihd tudi. Th xprimntal dtrmination rak propagation ritan ithin hydrauli bindr matrial ha bn idly rportd, ith main ontribution by Samy (979) Zigldorf (983). Among tt, thr-point bnding tt on nod pimn, dfind by RILEM rommndation (RILEM 985, RILEM 2), ar ud haratri mortar or onrt ritan propagation, by dtrmining fratur nrgy in a mod I fratur. Thi mthod, dvlopd by Hillrborg Ptron (98), prform a tabl pro bnding tt on a nod pimn. In bnding tt, tr fild i nonuniform ith a ontinuouly volving gradint along path rak propagation. Thi may rult in a variation in nrgy pr unit ara nary for rak

2 propagat J = D ( h, T ) a hfar a ritant tion a noth () plan volv. Morovr, in bnding tt, lngth Th rak proportionality propagation offiint i rlativly D(h,T) hort, i alld noth moitur hih prmability initiat rak it i propagation a nonlinar do funtion not hav ral rlativ rak humidity haratriti. h tmpratur Conquntly, T (Bažant mor nrgy Najjar i 972). ndd Th in moitur rak ma initiation balan pro. rquir A pri that variation analyi in tim rak ma propagation pr unit mhanim volum onrt ho ( that ontnt ) fratur b qual nrgy dtrmination divrgn i moitur afftd flux by paraiti J phnomna hn rak propagation path i hort, for xampl if r i a high ratio noth lngth id lngth. = J (2) Mot rult rportd in litratur rport on Th matrial ontnt bhaviour an at b room xprd tmpratur, a aftr um onrt vaporabl ha bn hatd variou tmpratur (apillary, vapor, n oold. adorbd Th ) tudi ntially non-vaporabl valuat (hmially ridual ritan bound) onrt matrial n (Mill 966, (Didrik Pantazopoulo t al. 988, Mill RILEM 995). 2, It i Fltti raonabl t al. 996, aum Shrflr that 995, vaporabl Chan t al. 2-, i a funtion Chan t al. 2-2, rlativ Mnou humidity, t al. h, dgr 26). Or hydration, mor ambitiou α, projt dgr hav ilia fum trid ration, dtrmin α onrt, i.. = (h,α,α ) bhaviour = ag-dpndnt at high tmpratur, orption/dorption but tt iorm ar mor (Norling diffiult Mjonll 997). prform. Undr In thi gnral, aumption tting tmpratur by ubtituting hav Equation bn limitd in 6 C, Equation hih 2 on i obtain rfrn tmpratur for fir ondition in a building. Bazant Kazmi (99), Khoury t al. (985), Noumoé t al. (994), Fltti t al. (996) hrportd on omprion or thr-point ( D h) = α α n (3) bnding h ttt, ith h rult α up 6 C. α Mot rportd tt hav bn prformd on ordinary onrt, ith vry f uing highprforman hr / h i lop orption/dorption onrt (HPC). Th prnt tudy iorm (alo alld moitur apaity). Th invtigat HPC. Thr-point bnding tt hav govrning quation (Equation 3) mut b ompltd bn arrid out at high tmpratur up 9 C on by appropriat boundary initial ondition. nod pimn HPC mortar. Th volution Th rlation btn amount vaporabl tnaity paramtr ith tmpratur hav bn rlativ humidity i alld adorption dtrmind rportd. Analyi SEM iorm if maurd ith inraing rlativity mirograph pimn aftr hating humidity dorption iorm in oppoit ooling ha bn ud hlp undrt a. Nglting ir diffrn (Xi t al. 994), in matrial bhaviour. folloing, orption iorm ill b ud ith rfrn both orption dorption ondition. By ay, if hytri moitur 2 MATERIALS AND METHODS iorm ould b takn in aount, diffrnt rlation, vaporabl v rlativ humidity, mut Th invtigatd mortar matrial i a mixtur b ud aording ign variation alibratd normalizd, mnt, mixd rlativity humidity. Th hap orption ith upr-platiizr, fin partil fum iorm for HPC i inflund by many paramtr, ilia. Th maximum partil iz alibratd pially tho that influn xtnt rat i 2 mm. Th mnt i a CEM 52.5 produt hmial ration, in turn, dtrmin por produd by Viat, upr-platiizr trutur por iz ditribution (--mnt ontaining polyarboxilat dlivrd in liquid form ratio, mnt hmial ompoition, SF ontnt, i from Sika. Thi mortar matrial ha a lo uring tim mthod, tmpratur, mix additiv, poroity, ith a / ratio.25. Th mortar i t.). In litratur variou formulation an b plad in a mould hih i vibratd aording a found drib orption iorm normal trit prool. At mid-lngth mould r onrt (Xi t al. 994). Hovr, in prnt ar. mm idth blad hih form noth papr mi-mpirial xprion propod by during moulding pro. Thn, for 24 hour Norling Mjornll (997) i adoptd bau it mould i prottd ith a plati ht prvnt moitur xpliitly lot. aount Th mould for produ volution thr pimn hydration that ration ar alibratd SF in ontnt. iz Thi ight. orption Th pimn iorm ar rad primati ith a quar tion, y maur 6x25x25 mm 3. Although hav produd pimn ith varying noth lngth, prnt tt rult only for tho that ar mm ( h, α, α ) = G ( α, α ) long. Th tt r arrid out on a ZWICK Z4 ( g α α ) h tting mahin quippd ith a 6 C (4) tmpratur hating apaity indutrial furna. Th tup i quippd ith a pial ( g αxtnomtr, α ) h bad K ( α, α ) on maurmnt LVDT nor plad outid furna. A diffrntial ytm, uing alumina rod poitiond axially through furna, maur hr firt diplamnt trm (gl iorm) from rprnt uppr punh ard phyially bound lor (adorbd) punh; thi diplamnt ond ortially trm (apillary orrpond iorm) rprnt pimn apillary hight variation. Thi in xprion a uniaxial i omprion valid only for tt. lo Th ontnt high tmpratur SF. Th offiint thr-point Gbnding rprnt tt apparatu amount ha bn adaptd pr unit volum thi xtnomtr. hld in gl Th por maurd at % for rlativ humidity, diplamnt it an b xprd loading point (Norling ar rordd Mjornll during 997) a tt. G ( α, α ) = k α k α vg vg (5) hr k vg k vg ar matrial paramtr. From maximum amount pr unit volum that an fill all por (both apillary por gl por), on an alulat K a on obtain α α K (, ) = g α α.88α.22α G g α α (6) Th matrial paramtr k vg k vg g an Figur. Vi a pimn in tting apparatu aftr a b alibratd by fitting xprimntal data rlvant tt i prformd at 5 C tmpratur. fr (vaporabl) ontnt in onrt at variou Th ag prnt (Di Luzio tudy pifially Cuati 29b). xamin mhanial loading hil pimn i hatd. A thr 2.2 Tmpratur pha rmal volution yl i applid matrial during a tt: () a hating pha at a rat 3.3 C/min, Not that, at (2) arly a ag, holding in tim hmial aftr ration targt tmpratur aoiatd ith i rahd, mnt hydration (3) a ooling SF pha ration at a rat ar xormi, 2.5 C/min. Th tmpratur holding tim fild i i dividd not uniform in for non-adiabati priod. Th firt ytm -hour vn if priod nvironmntal i applid in all tmpratur tt i i ud ontant. qualiz Hat ondution tmpratur an b dribd pimn in onrt, loading at lat apparatu. for tmpratur Th ond not holding xding tim C priod (Bažant i haratrizd Kaplan by mhanial 996), by loading, Fourir la, nd hih gnrally rad ith failur pimn; tim i variabl dpnd on q = λ T tting tmpratur. A ontant.5 mm/min (7) diplamnt rat i applid pimn, ration hr q for i i maurd hat flux, during T i mhanial abolut loading. tmpratur, Th folloing λ i tting hat ondutivity; tmpratur in r thi applid: 25, 5, 3, 5, 7 C. Th matrial Proding FraMCoS-7, May 23-28, 2

3 a not ttd at 9 C bau it trngth a inuffiint. On pimn tmpratur had drad room tmpratur, it a rmovd from furna a SEM miroopy analyi a prformd. 3 RESULTS AND DISCUSSION Th applid mthod rquir u dfltion ontrol for pimn, both for mauring diipatd nrgy during omplt tabl ruptur matrial, for tudying fraturd tion aftrard. To nur that rak propagation i tabl ith no diipation upplmntary nrgy, our tt impod a diplamnt intad for. Important rult r obtaind on fratur load at variou tmpratur uing thr-point bnding tt. Figur 2 ho load-diplamnt urv from tt prformd on mm noth lngth pimn at variou tting tmpratur. Th rult ho laial bll-hap volution haratrizd by a pak load follod by a tning urv.,45,4,35,3 ) N,25 ( K d a o,2 L,5,,5 a = T=25 C T=5 C T=3 C T=5 C T=7 C,,2,3,4 Diplamnt (mm) Figur 2. Evolution pimn maximal applid load v. dfltion, for a mm lngth nod pimn at variou tting tmpratur. A global analyi rult uggt that urv an b laifid in group. Th firt group inlud tt prformd at tmpratur ranging from 25 5 C, ar haratrizd by high maximal load pronound pak. Th ond group only inlud tt prformd at 7 C, i haratrizd by a notiably rdud pak load follod by a progriv volution rulting load. JIn = D ( thi h, T ) a, h raking that ourrd aftr load pak i mor progriv i imilar pudo-dutility. Th proportionality Figur 2 offiint ho D(h,T) tranition in moitur matrial prmability bhaviour it a i a nonlina tmpratur inra from rlativ 5 humidity 7 C. h Within tmpratur firt group, Najjar pak 972). load inra Th moitur a ma balan tmpratur inra that from variation 25 in 3 C tim (ith ma xption a light volum dra onrt at 5 C), ( ontnt n ) b q pak load dra divrgn at 5 C. moitur flux J,4,35,3 ) N ( K,25 D A O,2 L k a,5 P,,5 = J Th ontnt an b xprd a vaporabl (apillary a vapor, adorbd ) non- (hmially bound) n (Mil Pantazopoulo Mill 995). It i ra aum that vaporabl i a fu rlativ humidity, h, dgr hydration dgr ilia fum ration, α, i.. = = ag-dpndnt orption/dorption (Norling Mjonll 997). Undr thi aum by ubtituting Equation in Equati obtain 2 3 h ( D h) = α α h t h Tmpratur ( C) α α Figur 3. Variation maximal applid for on a mm lngth nod pimn v. tting tmpratur. hr / h i lop orption/ iorm (alo alld moitur apa Th tning govrning urv quation during (Equation tt at 3) 25 mut b 5 C ar mor by appropriat pronound boundary than at initial or onditi tmpratur; thi indiat Th rlation that btn matrial i amount mor fragil at thi tmpratur rlativ rang, humidity partiularly i alld at 5 C. In ummary, iorm matrial if maurd bhaviour ith hang inraing notably from 5 humidity 7 C. dorption Figur 3 ho iorm in th volution a. maximal Nglting load ir ith diffrn tting (Xi t al. tmpratur ud in folloing, Figur 2; orption load valu iorm ar ill b avragd ovr thr rfrn tt at both ah orption tmpratur. dorption Th dra maximal By load ay, at a if tt tmpratur hytri 5 C i apparnt. iorm Variou ould xplanation b takn in for aount, thi phnomnon hav rlation, bn vaporabl propod. For xampl, v rlativ humi Khoury t al. (985) b ud uggtd aording that at mirotrutur ign varia al at thi tmpratur, rlativity humidity. fluidity Th inra, hap hih ould indu iorm a dra for HPC in i inflund Van dr Waal by many p for btn pially li tho alium that iliat influn hydrat xtnt (CSH) oat, lading hmial a ration dra in, in urfa turn, dtrm nrgy oat. trutur W ill xamin por iz thi phnomnon ditribution (ratio, mnt hmial ompoition, SF latr. Th matrial tnaity uring tim ha bn mthod, haratrizd tmpratur, a mix part matrial t.). bhaviour In litratur at high tmpratur. variou formulatio Th rlvant paramtr found i drib tr intnity orption far iorm (K I ), hih i dtrmind onrt (Xi from t analytial al. 994). formula Hovr, in th bad on Mhani papr Continuum mi-mpirial Mdia ory xprion pro aount for variou Norling gomtri Mjornll (997) loading i adoptd b ondition. Proding FraMCoS-7, May 23-28, 2

4 J = Th D ( maximal h, T ) h tr intnity far for mm () noth lngth pimn at variou tmpratur ar providd Th proportionality in Figur 4. offiint Thi paramtr D(h,T) i i a linar alld funtion moitur prmability maximal load it ithin i a nonlinar a givn tt; funtion thi haratriti rlativ humidity provid h ommonality tmpratur T (Bažant ir volution Najjar 972). (Fig. Th 3). moitur Hn, at ma tmpratur balan rquir ovr 3 C, that variation tr intnity tim far dra ma pr harply unit ith volum inraing onrt tmpratur. ( ontnt In or ) b qual ord, matrial divrgn fratur ritan, moitur flux a J haratrizd by it tnaity, dra ith inraing tmpratur. An inra in tmpratur K I from 5 3 C ha bn = obrvd J likly rprnt a rtart (2) an alration mnt dhydration pro at Th origin ontnt link btn an b xprd variou a mortar um ontitunt vaporabl (Rfrn). (apillary, vapor, Fratur adorbd nrgy ) i dfind a non-vaporabl nrgy nary (hmially rat bound) a rak ith a unity urfa n (Mill 966, during Pantazopoulo a mod I ruptur. Mill 995). It an b It dtrmind i raonabl from RILEM aum that (985) vaporabl rommndation i a through funtion folloing rlativ humidity, quation: h, dgr hydration, α, dgr ilia fum ration, α G W, i.. = (h,α,α ) = = ag-dpndnt orption/dorption iorm F (Norling 2AMjonll 997). Undr thi aumption () lig by ubtituting Equation in Equation 2 on hr obtain W = nrgy rprntd by ara undr rordd load-diplamnt urv (auming that all furnihd nrgy i ud rat rak); h ( D h) = A lig = ritant tion ara α ituatd α in n noth (3) h t h α α plan. Th tmpratur inra ha an fft on mhanial hr / h proprti i lop onrt; orption/dorption thi an b n in iorm volution (alo alld moitur fratur apaity). nrgy ith Th tmpratur. govrning quation (Equation 3) mut b ompltd by Figur appropriat 5 ho boundary ho initial ara ondition. undr loaddiplamnt Th rlation urv, btn rprnting amount tal vaporabl nrgy, hang a rlativ tmpratur humidity inra, i alld adorption Figur 6 ho iorm volution if maurd ith fratur inraing nrgy rlativity G F ith tmpratur. humidity Th dorption urv iorm appar imilar in oppoit bau Ga. F i proportional Nglting ir diffrn nrgy W. (Xi Figur t al. 6994), ho in a dra folloing, G F orption at 5 C, iorm follod ill by b an ud inra ith until rfrn 3 C, both a light orption dra dorption from 3 ondition. 5 C, By finally ay, an harp if dra hytri at tmpratur moitur highr than iorm 5 C. ould Rult b takn at 9 C in ar aount, not hon; diffrnt tt ould rlation, not vaporabl b ompltd bau v rlativ pimn humidity, brok mut during b ud hating aording bfor ign mhanial variation load a applid. rlativity Thu, humidity. ddu Th that hap matrial ritan orption iorm fratur for HPC nrgy i inflund i null by at many 9 C. paramtr, That i onitnt pially tho ith that volution influn xtnt G F rat urv in Figur hmial 6. Figur ration 5, 6 uggt in turn, that dtrmin a tmpratur por trutur 4 C i optimal. por iz ditribution (--mnt ratio, To bttr mnt undrt hmial matrial ompoition, bhaviour SF ontnt, at high tmpratur, uring tim mthod, prformd tmpratur, mirotrutur mix additiv, tudi. Sampl t.). In litratur pimn variou ttd formulation variou an b tmpratur found drib r oold orption analyzd iorm uing normal SEM. Chmial onrt (Xi analy t al. r 994). alo Hovr, prformd in but ar prnt not diud papr hr. mi-mpirial Figur 7(a-b) ho xprion typial propod mirograph by takn Norling at 25 Mjornll 5 C, (997) rptivly, i adoptd Figur bau 8(a-b-) it xpliitly aount for volution hydration ration 3 SF ontnt. Thi orption iorm rad 25 ( ) = G ( α, α ) ( g α α ) h ) h2, α, α 5, m /m 5 ( N K I 5 hr firt trm (gl iorm) rprnt phyially bound (adorbd) ond trm (apillary iorm) rprnt apillary. Thi xprion 2 3i 4 valid 5 only 6for 7 lo 8 ontnt 9 SF. Th offiint Tmpratur G rprnt ( C) amount pr unit volum hld in gl por at % Figur 4. Evolution maximal tr intnity far on rlativ humidity, it an b xprd (Norling mm lngth nod pimn v. tting tmpratur. Mjornll 997) a,2 α, α = k α,8 vg G ( ) k α vg,2 ( g α α ) h K ( α, α ) ao= mm (4) (5),6 hr k vg k vg ar matrial paramtr. From maximum,4 amount pr unit volum that an fill ) all por (both apillary por gl por), on m,2 an alulat K,m a on obtain N, (K,8 g α α W.88α.22α G,6 (6) K ( α, α ) =,4 g α α h Th, matrial paramtr k vg k vg g an b alibratd by fitting 2 3 xprimntal 4 5 6data 7rlvant 8 9 fr (vaporabl) ontnt in onrt at Tmpratur ( C) variou ag (Di Luzio Cuati 29b). Figur 5. Evolution ara undr load-diplamnt urv on mm lngth nod pimn v. tting tmpratur. 2.2 Tmpratur volution Not that, at arly ag, in hmial ration diplay tho at 3, 5, 7 C. Th volution aoiatd ith mnt hydration SF ration CSH oat ith tmpratur an b larly ar xormi, tmpratur fild i not uniform n. At 25 C tmpratur, CSH produt appar a for non-adiabati ytm vn if nvironmntal indd light ht. At 5 C, matrial prnt tmpratur i ontant. Hat ondution an b a larg nrk rak; on m i viibl in dribd in onrt, at lat for tmpratur not Figur 7-b. xding C (Bažant Kaplan 996), by Th apparan rak an b xplaind by Fourir la, hih rad rmal dilation that indu paration CSH ht. Thi paration lad q = λ T diminution ir mutual attration for. Th (7) akning link btn hydrat an initiat hr miro-dft q i hat that flux, an failitat T i liding abolut (a dra tmpratur, matrial λ i ritan hat ondutivity; an b obrvd in thi at thi tmpratur). At a tmpratur 3 C (Fig. Proding FraMCoS-7, May 23-28, 2

5 ,25 ao= mm,2 ),5 m m / (NF G, = D (h, T ) h i probably du 3 C. Th CSH Jtranformation matrial dhydration hih onnt prviouly paratd ht. Th proportionality offiint D(h,T) moitur prmability it i a nonlina rlativ humidity h tmpratur Najjar 972). Th moitur ma balan that variation in tim ma volum onrt ( ontnt ) b q divrgn moitur flux J = J,5 t Tmpratur ( C) Figur 6. Variation fratur nrgy mm lngth nod pimn v. tting tmpratur. Th ontnt an b xprd a vaporabl (apillary a vapor, adorbd ) non- a- T = 3 C (hmially bound) n (Mil Pantazopoulo Mill 995). It i ra aum that vaporabl i a fu rlativ humidity, h, dgr hydration dgr ilia fum ration, α, i.. = = ag-dpndnt orption/dorption (Norling Mjonll 997). Undr thi aum by ubtituting Equation in Equati obtain a- T = 25 C b- T = 5 C Figur 7. SEM mirograph mortar at variou tting tmpratur. Hydrat ar abundant at 25 C 5 C, but rak appar at 5 C. 8-a), morphology bom mor ompat CSH bom ordd. Clo attntion mirograph at thi tmpratur rval that miro-rak that appard at 5 C ar bridgd by CSH tranform produt; thi phnomnon larly xplain matrial ritan inra at h ( D h) = α bh T =t 5 C h α α α hr / h i lop orption/ iorm (alo alld moitur apa govrning quation (Equation 3) mut b by appropriat boundary initial onditi Th rlation btn amount rlativ humidity i alld iorm if maurd ith inraing humidity dorption iorm in th a. Nglting ir diffrn (Xi t al. folloing, orption iorm ill b rfrn both orption dorption T = 7 C By - ay, if hytri Figur 8. SEM mirograph invtigatd mortar hn iorm ould b -takn intting aount, ubjtd a- 3 C, b-5 C 7 C rlation, vaporabl v rlativ tmpratur. Whra hydrat (CSH) ar prnt at 3 humi b noud ign varia 5 C, uh pha ar moraording viibl at 7 C. rlativity humidity. Th hap HPC ixhibit inflund by many p At 5 C (Fig.iorm 8-b), formatrial rgular pially tho that influn xtnt miro-raking. Th CSH hav dhydratd but ar hmial in bgan turn, dtrm till lightly prnt, ration Portlit, pha trutur por iz ditribution it dompoition. But at 7 C (Fig. 8-), CSH (mnt ompoition, SF produt ar noratio, longr viiblhmial hav bn uring tim mthod, tmpratur, mix rplad by CS or CS2 pha trutur. Th t.). In litratur variou formulatio tranformation ubqunt diapparan found drib orption iorm CSH oat at tmpratur 7 C highr ar t al. 994). Hovr, in th aompanid by onrt a drati (Xi rdution in matrial papr mi-mpirial xprion pro ritan (Fig. 3). Norling Mjornll (997) i adoptd b A yni SEM mirograph analyi Proding FraMCoS-7, May 23-28, 2

6 a J hmial = D ( h, T ) analyi h (not prntd hr) rvald () that volution mortar mhanial proprti ith Th tmpratur proportionality i orrlatd offiint D(h,T) mirotrutur i alld volution, moitur prmability lo, it i dhydration a nonlinar ration. funtion Chmial rlativ dompoition humidity h uing tmpratur x-ray analyi T (Bažant or rmogravimtri Najjar 972). Th analyi moitur (TGA) ma hould balan alo rquir onfirm our that rult; variation in invtigation tim ill b ma undrtakn pr unit latr. volum Thi onrt matrial ( hould ontnt b furr ) b ttd qual at thi partiular divrgn tmpratur. moitur Latly, flux J invtigatd matrial i mor imilar mortar than onrt. Thu, unlik onrt, propagation initiatd rak i unlikly = Jb ppd by prn a grain. (2) Th ontnt an b xprd a um 4 CONCLUSIONS vaporabl (apillary, vapor, adorbd ) non-vaporabl Th (hmially aim bound) prnt ork i invtigat high n (Mill 966, prforman Pantazopoulo onrt Mill mortar 995). bhaviour It i hn raonabl ubjtd aum inraing that tting vaporabl tmpratur. A thr-point i a funtion bnding tt rlativ apparatu humidity, a dvlopd h, dgr in alumina hydration, matrial, α, tt dgr r ondutd ilia fum by ration, loading α mm lngth nod, i.. = (h,α,α ) pimn = ag-dpndnt that had bn orption/dorption hatd variou tmpratur iorm (25, (Norling 5, 3, Mjonll 5, 7, 997). Undr 9 C). thi aumption by - ubtituting Blo a tmpratur Equation in 5 C Equation matrial 2 on xhibitd obtain nonlinar quai-brittl bhaviour ith good ritan. At tmpratur up 7 C, bhaviour hangd nonlinar ith pudo-dutility notably lr ritan. h Th optimal ritan i obtaind ( D h) = α α n (3) ithin h 3-5 C h tmpratur α α rang, matrial xhibit no ritan at 9 C. - Th tnaity paramtr, inluding tr hr / h i lop orption/dorption intnity far K I fratur nrgy G F, hav iorm (alo alld moitur apaity). Th bn dtrmind. Thir volution ith tmpratur govrning quation (Equation 3) mut b ompltd bhav in a imilar fahion a pak load v. by appropriat boundary initial ondition. tmpratur. Th rlation btn amount vaporabl - An analyi SEM mirograph hod that rlativ humidity i alld adorption rak firt our at a tmpratur 5 C ith a iorm if maurd ith inraing rlativity draing pak load. A bridging phnomnon for humidity dorption iorm in oppoit rak at 3 C a n obrvd, aompanid a. Nglting ir diffrn (Xi t al. 994), in by CSH tranformation an inra pak folloing, orption iorm ill b ud ith load. A tmpratur furr inrad, hydrat rfrn both orption dorption ondition. produt volvd a a n miro-raking phnomnon By ay, if hytri moitur appard at 5 C. Finally, diapparan iorm ould b takn in aount, diffrnt hydrat at tmpratur ovr 7 C a aompanid rlation, vaporabl v rlativ humidity, mut by a drati dra in matrial ritan. Th b ud aording ign variation mirotrutur obrvation r onitnt ith rlativity humidity. Th hap orption maroopi rmo-mhanial bhaviour iorm for HPC i inflund by many paramtr, matrial, a dtrmind by thr-point bnding pially tho that influn xtnt rat tt. Analyi hydrat volution ha bn hmial ration, in turn, dtrmin por propod. trutur por iz ditribution (--mnt ratio, mnt hmial ompoition, SF ontnt, uring tim mthod, tmpratur, mix additiv, REFERENCES t.). In litratur variou formulation an b found drib orption iorm normal Bazant, Z.P. Kazmi, M.T. 99. Dtrmination fratur onrt nrgy, (Xi pro t al. zon 994). lngth Hovr, brittln in numbr prnt from papr iz fft, mi-mpirial ith appliation xprion rok propod onrt. by Norling Intrnational Mjornll Journal (997) Fratur i 44: adoptd -3. bau it Chan, xpliitly Y.N., aount Luo X., for Sun, W., volution 2, Efft hydration high ration tmpratur SF ontnt. ooling rgim Thi orption on ompriv iorm rad trngth por proprti high prforman onrt, Contrution Building Matrial, 4 (2) Chan, Y.N., Luo X., Sun, W., 2, Compriv trngth por trutur high-prforman onrt aftr xpour ( h, high α, α ) = G ( tmpratur α, α ) up 8 C, Cmnt Conrt Rarh 3 (2) ( g α α ) h Diamond, S Th Mirotrutur Cmnt Pat (4) in Conrt, VIII Intrnational Cong. Chm. Cm, Rio d ( g α α ) h Janiro 986 : 3-2. K ( α, α ) Didrih, U., Jumppanm, U.-M. Pnttala, V Matrial proprti high trngth onrt at lvatd tmpratur, IABSE 3 th Congr, Hlinki, 988. Flltti, hr R., firt Gambarova, trm (gl P.G., iorm) Roati, G.P., rprnt Cori, F. Giannuzzi, G Ridual Mhanial proprti phyially high trngth bound Conrt (adorbd) Subjtd High Tmpratur ond trm Cyl. (apillary Pro. 4iorm) Intrnational rprnt Sympoium on Utilization apillary. High Thi Strngth/High xprion i Prforman valid only for Conrt, lo ontnt Pari, Fran SF. Th 996, offiint G rprnt amount GjØrv, pr O.E., unit Sornn, volum S.F. hld in Arnn, gl A. por 977. at % Noth nitivity fratur ughn onrt, Cmnt rlativ humidity, it an b xprd (Norling onrt Rarh, 7: Hillrborg, Mjornll 997) A. Ptron, a P.E. 98. Fratur mhanial alulation. Tt mthod rult for onrt imilar matrial. Proding 5th Intrnational G ( Confrn α, α ) = k on α Fratur, k Cann, α 98. (5) vg vg Kaplan, M.F. 96. Crak propagation fratur onrt, A.C.I. Journal, 58 (5): Khoury, hr kg.a., vg Graingr, k vg ar B.N. matrial Sullivan, paramtr. G.P.E From Strain maximum onrt amount during firt hating pr unit 6 C volum undr that load. an fill Magazin all por (both Conrt apillary Rarh, por 37: gl por), on Mnou, an alulat A., Mounajd, K G., Boua, H., Pinaud, A., Carr, H., a on obtain ridual fratur nrgy mnt pat, mortar onrt ubjt high tmpratur, Thortial Applid Fratur Mhani 45 (26) g α α Noumo, A., Clatr, P., Dbiki, G. Bolvin, M.,.88α.22α G 994. High tmpratur Efft High Prforman Conrt: (6) K ( Strngth α, α ) = poroity. Third CANMET/ACI Intrnational Confrn on Durability g αconrt, α Ni, Fran, May, 994. RILEM 5-FMC on fratur Mhani onrt, 985. Dtrmination Th matrial paramtr fratur Enrgy k Mortar Conrt vg k vg g an by man thr-point bnding tt on nod Bam, b alibratd by fitting xprimntal data rlvant Matrial Strutur 8(6): RILEM fr (vaporabl) TC 29-MHT 2, Tt ontnt mthod in for onrt mhanial at variou proprti ag (Di onrt Luzio at high Cuati tmpratur 29b). Rommndation, Part8-Stady-tat rp rp rovry for rvi aidnt ondition. Matrial Strutur 33: 6-3. Shrflr, 2.2 Tmpratur B.A.F.E, 995. volution Coupld rmo-hydro-mhanial pro in porou mdia inluding pollutant tranport, Not that, at arly ag, in hmial ration Arhiv Computational Mthod in Enginring, in aoiatd Environmntal ith Enginring mnt hydration 2(3): -. by CIMM, SF Barlona ration ar - xormi, Spain. tmpratur fild i not uniform Samy, for non-adiabati R.N ytm Linar vn lati if fratur nvironmntal mhani tmpratur paramtr i onrt, ontant. Fratur Hat mhani ondution onrt, an Ed, b F.H. Wittman, Edir, Fratur Mhani Conrt, dribd in onrt, at lat for tmpratur not Elvir Sin Publihr, Nrl (983), pp. 4- xding 46. C (Bažant Kaplan 996), by Zigldorf, Fourir la, S hih Fratur rad mhani paramtr hardnd mnt pat, aggrgat intrfa, Fratur q = Mhani λ T Conrt, Ed. F.H. Wittman, Edir, Fratur (7) Mhani Conrt, Elvir Sin Publihr, Nrl (983), pp hr q i hat flux, T i abolut tmpratur, λ i hat ondutivity; in thi Proding FraMCoS-7, May 23-28, 2