Cellulose ether ntawm tus kheej-leveling mortar

Cov teebmeem ntawmhydroxypropyl methyl cellulose etherNyob rau hauv lub fluidity, dej tuav thiab kev sib txuas lub zog ntawm tus kheej-leveling mortar tau kawm. Cov txiaj ntsig tau pom tias HPMC tuaj yeem txhim kho cov dej tuav ntawm tus kheej-leveling mortar thiab txo qhov sib xws ntawm mortar. Kev taw qhia ntawm HPMC tuaj yeem txhim kho lub zog sib txuas ntawm mortar, tab sis lub zog compressive, flexural zog thiab fluidity raug txo. SEM qhov sib piv qhov ntsuas tau ua tiav ntawm cov qauv, thiab cov txiaj ntsig ntawm HPMC ntawm cov nyhuv retarding, cov nyhuv tuav dej thiab lub zog ntawm mortar tau piav qhia ntxiv los ntawm cov dej ntawm cov cement ntawm 3 thiab 28 hnub.

Cov lus tseem ceeb:self-leveling mortar; Cellulose ether; Fluidity; Kev tuav dej

0. Taw qhia

Self-leveling mortar tuaj yeem tso siab rau nws tus kheej qhov hnyav los tsim lub hauv paus tiaj tus, du thiab muaj zog ntawm lub substrate, thiaj li yuav nteg lossis khi lwm cov ntaub ntawv, thiab tuaj yeem nqa tawm thaj tsam loj ntawm kev tsim kho kom zoo, yog li ntawd, cov khoom lag luam siab yog ib qho khoom siv zoo. tseem ceeb heev feature ntawm tus kheej-leveling mortar; Tshwj xeeb tshaj yog raws li ib tug loj ntim, reinforced ntom los yog qhov sib txawv tsawg tshaj li 10 hli backfill los yog reinforcing siv cov khoom grouting. Ntxiv nrog rau qhov zoo fluidity, tus kheej-leveling mortar yuav tsum muaj qee yam dej tuav thiab kev sib koom ua ke, tsis muaj qhov tshwm sim los ntshav sib cais, thiab muaj cov yam ntxwv ntawm adiabatic thiab qis kub nce.

Feem ntau, tus kheej-leveling mortar yuav tsum muaj dej zoo, tab sis qhov tseeb fluidity ntawm cov cement slurry feem ntau tsuas yog 10 ~ 12 cm. Self-leveling mortar tuaj yeem ua rau nws tus kheej compacting, thiab lub sij hawm pib pib yog ntev thiab lub sij hawm zaum kawg yog luv. Cellulose ether yog ib qho ntawm cov khoom siv tseem ceeb ntawm cov khoom sib xyaw ua ke, txawm tias qhov sib ntxiv yog tsawg heev, tab sis tuaj yeem txhim kho kev ua haujlwm ntawm mortar, nws tuaj yeem txhim kho qhov sib xws ntawm mortar, kev ua haujlwm, kev sib txuas thiab kev tuav dej, muaj lub luag hauj lwm tseem ceeb heev nyob rau hauv lub teb ntawm npaj-mixed mortar.

1. Cov ntaub ntawv raw thiab txoj kev tshawb fawb

1.1 Cov khoom siv raw

(1) Ordinary P·O 42.5 qib cement.

(2) Cov khoom siv xuab zeb: Xiamen ntxuav hiav txwv xuab zeb, particle loj yog 0.3 ~ 0.6 hli, cov ntsiab lus dej yog 1% ~ 2%, kev ziab ziab.

(3) Cellulose ether: hydroxypropyl methyl cellulose ether yog cov khoom ntawm hydroxyl hloov los ntawm methoxy thiab hydroxypropyl, feem, nrog viscosity ntawm 300mpa·s. Tam sim no, feem ntau ntawm cov cellulose ether siv yog hydroxypropyl methyl cellulose ether thiab hydroxyethyl methyl cellulose ether.

(4) superplasticizer: polycarboxylic acid superplasticizer.

(5) Redispersible latex hmoov: HW5115 series tsim los ntawm Henan Tiansheng Chemical Co., Ltd.

1.2 Cov txheej txheem xeem

Kev ntsuas tau ua raws li kev lag luam tus qauv JC / T 985-2005 "Cement-based Self-leveling Mortar rau Kev Siv Hauv av". Lub sijhawm teeb tsa tau txiav txim siab los ntawm kev xa mus rau tus qauv sib xws thiab lub sijhawm teeb tsa ntawm JC / T 727 cement paste. Self-leveling mortar specimen forming, dabtsi yog khoov thiab compressive zog test xa mus rau GB / T 17671. Test method of bond strength: 80mmx80mmx20mm mortar test block yog npaj ua ntej, thiab nws muaj hnub nyoog tshaj 28d. Qhov saum npoo yog roughened, thiab cov dej saturated ntawm qhov chaw yog wiped tawm tom qab 10min wetting. Cov tshuaj khib nyiab yog nchuav rau ntawm qhov chaw polished nrog qhov loj ntawm 40mmx40mmx10mm. Bond zog raug kuaj thaum muaj hnub nyoog tsim.

Scanning electron microscopy (SEM) tau siv los txheeb xyuas cov morphology ntawm cov ntaub ntawv cementified hauv slurry. Hauv txoj kev tshawb no, kev sib xyaw ntawm txhua cov ntaub ntawv hmoov yog: ua ntej, cov ntaub ntawv hmoov ntawm txhua qhov sib xyaw ua ke, thiab tom qab ntawd ntxiv rau cov dej npaj rau kev sib xyaw. Cov nyhuv ntawm cellulose ether ntawm tus kheej-leveling mortar yog soj ntsuam los ntawm lub zog, tuav dej, fluidity thiab SEM microscopic xeem.

2. Cov txiaj ntsig thiab kev tshuaj xyuas

2.1 Mobility

Cellulose ether muaj qhov cuam tshuam tseem ceeb ntawm kev tuav dej, sib xws thiab kev tsim kho ntawm tus kheej qib mortar. Tshwj xeeb tshaj yog raws li tus kheej-leveling mortar, fluidity yog ib qho tseem ceeb indexes los ntsuas qhov kev ua tau zoo ntawm tus kheej-leveling mortar. Nyob rau ntawm qhov chaw ntawm kev ua kom ntseeg tau lub cev muaj pes tsawg leeg ntawm mortar, fluidity ntawm mortar tuaj yeem hloov kho los ntawm kev hloov cov ntsiab lus ntawm cellulose ether.

Nrog kev nce ntawm cellulose ether cov ntsiab lus. Lub fluidity ntawm mortar txo qis. Thaum qhov ntau npaum li cas yog 0.06%, fluidity ntawm mortar txo los ntawm ntau tshaj 8%, thiab thaum noj yog 0.08%, fluidity txo los ntawm ntau tshaj 13.5%. Nyob rau tib lub sijhawm, nrog rau kev ncua ntawm lub hnub nyoog, qhov ntau npaum li cas qhia tau hais tias tus nqi ntawm cellulose ether yuav tsum tau tswj nyob rau hauv ib tug tej yam ntau yam, ntau npaum li cas yuav coj tsis zoo cuam tshuam rau lub mortar fluidity. Cov dej thiab cov cement nyob rau hauv lub mortar tsim cov slurry huv si los sau cov xuab zeb sib txawv, thiab qhwv ib ncig ntawm cov xuab zeb los ua lub luag haujlwm lubricating, kom cov mortar muaj qee yam fluidity. Nrog rau kev qhia txog cellulose ether, cov ntsiab lus ntawm cov dej dawb hauv lub kaw lus raug txo qis, thiab cov txheej txheej txheej ntawm cov xuab zeb sab nrauv yog txo, yog li txo qhov ntws ntawm mortar. Vim qhov yuav tsum tau ntawm tus kheej-leveling mortar nrog cov fluidity siab, tus nqi ntawm cellulose ether yuav tsum tau tswj nyob rau hauv ib tug tsim nyog ntau yam.

2.2 Kev tuav dej

Kev tuav dej ntawm mortar yog qhov ntsuas tseem ceeb los ntsuas qhov ruaj khov ntawm cov khoom hauv cov khoom sib xyaw ntawm cov cement mortar. Ntxiv qhov tsim nyog ntawm cellulose ether tuaj yeem txhim kho cov dej tuav ntawm cov tshuaj khib nyiab. Txhawm rau ua kom cov tshuaj tiv thaiv hydration ntawm cov khoom siv cementing tag nrho, tus nqi tsim nyog ntawm cellulose ether tuaj yeem khaws cov dej hauv mortar rau lub sijhawm ntev los xyuas kom meej tias cov tshuaj tiv thaiv dej ntawm cov cementing tuaj yeem ua tiav.

Cellulose ether tuaj yeem siv los ua cov dej khaws cia vim tias cov pa oxygen atoms ntawm hydroxyl thiab ether bonds yog txuam nrog cov dej molecules los tsim hydrogen bonds, ua kom cov dej dawb ua dej ua ke. Nws tuaj yeem pom los ntawm kev sib raug zoo ntawm cov ntsiab lus ntawm cellulose ether thiab cov dej tuav tus nqi ntawm mortar uas cov dej tuav tus nqi ntawm mortar nce ntxiv nrog rau qhov nce ntawm cov ntsiab lus ntawm cellulose ether. Cov dej tuav cov nyhuv ntawm cellulose ether tuaj yeem tiv thaiv cov substrate los ntawm absorbing dej ntau dhau thiab ceev heev, thiab tiv thaiv dej evaporation, yog li xyuas kom meej tias cov slurry ib puag ncig muab dej txaus rau cement hydration. Kuj tseem muaj cov kev tshawb fawb qhia tias ntxiv rau cov cellulose ether, nws cov viscosity (molecular hnyav) kuj muaj kev cuam tshuam ntau dua rau cov dej khib nyiab, qhov viscosity ntau dua, cov dej tuav tau zoo dua. Cellulose ether nrog viscosity ntawm 400 MPa·S feem ntau yog siv rau tus kheej-leveling mortar, uas tuaj yeem txhim kho qib kev ua tau zoo ntawm mortar thiab txhim kho lub compactness ntawm mortar. Thaum cov viscosity siab tshaj 40000 MPa·S, cov dej tuav tau zoo lawm, thiab nws tsis haum rau tus kheej-leveling mortar.

Hauv txoj kev tshawb no, cov qauv ntawm mortar nrog cellulose ether thiab mortar tsis muaj cellulose ether raug coj mus. Ib feem ntawm cov qauv yog cov qauv 3d hnub nyoog, thiab lwm qhov ntawm cov qauv 3d hnub nyoog yog cov qauv kho rau 28d, thiab tom qab ntawd tsim cov khoom siv cement hydration hauv cov qauv yog kuaj los ntawm SEM.

Cov khoom hydration ntawm cov cement nyob rau hauv cov qauv dawb paug ntawm mortar qauv ntawm 3d hnub nyoog yog ntau tshaj li cov nyob rau hauv cov qauv nrog cellulose ether, thiab thaum muaj hnub nyoog 28d, cov khoom hydration nyob rau hauv cov qauv nrog cellulose ether yog ntau tshaj li nyob rau hauv cov qauv dawb paug. Kev ywg dej thaum ntxov ntawm cov dej yog ncua vim tias muaj cov txheej txheem ua yeeb yaj kiab uas tsim los ntawm cellulose ether rau ntawm cov cement hais thaum ntxov. Txawm li cas los xij, nrog rau kev ncua ntawm lub hnub nyoog, cov txheej txheem hydration pib maj mam. Lub sijhawm no, cov dej tuav ntawm cellulose ether ntawm cov slurry ua rau muaj dej txaus hauv slurry kom tau raws li qhov xav tau ntawm cov tshuaj tiv thaiv dej, uas yog qhov tsim nyog rau kev ua tiav ntawm cov tshuaj tiv thaiv dej. Yog li ntawd, muaj ntau cov khoom hydration nyob rau hauv slurry tom qab theem. Hais lus zoo, muaj dej dawb ntau dua hauv cov qauv dawb paug, uas tuaj yeem txaus siab rau cov dej uas xav tau los ntawm cov tshuaj cement thaum ntxov. Txawm li cas los xij, nrog kev nce qib ntawm cov txheej txheem hydration, ib feem ntawm cov dej hauv cov qauv yog siv los ntawm cov tshuaj tiv thaiv dej thaum ntxov, thiab lwm qhov yog poob los ntawm evaporation, ua rau cov dej tsis txaus hauv cov slurry tom qab. Yog li ntawd, 3d hydration khoom nyob rau hauv cov qauv dawb paug yog ntau dua. Tus nqi ntawm cov khoom hydration yog tsawg dua li cov khoom hydration hauv cov qauv uas muaj cellulose ether. Yog li ntawd, los ntawm qhov kev xav ntawm cov khoom siv dej, nws tau piav qhia dua tias ntxiv qhov tsim nyog ntawm cellulose ether rau mortar tuaj yeem txhim kho cov dej tuav ntawm slurry.

2.3 Teem sijhawm

Cellulose ether muaj qee yam cuam tshuam rau mortar, nrog rau kev nce ntawm cellulose ether cov ntsiab lus. Lub sij hawm teem ntawm lub mortar yog ces ncua. Cov nyhuv retarding ntawm cellulose ether yog ncaj qha ntsig txog nws cov yam ntxwv ntawm cov qauv. Cellulose ether muaj dehydrated qabzib nplhaib qauv, uas tuaj yeem tsim cov suab thaj calcium molecular complex rooj vag nrog calcium ions hauv cement hydration tov, txo cov concentration ntawm calcium ions hauv cement hydration induction lub sij hawm, tiv thaiv kev tsim thiab nag lossis daus ntawm Ca (OH) 2 thiab calcium ntsev. crystals, thiaj li mus ncua cov txheej txheem hydration ntawm cement. Cov nyhuv retarding ntawm cellulose ether ntawm cov cement slurry tsuas yog nyob ntawm qhov kev hloov pauv ntawm alkyl thiab muaj kev sib raug zoo nrog nws qhov hnyav molecular. Qhov me dua qhov hloov pauv qib ntawm alkyl, qhov loj dua cov ntsiab lus ntawm hydroxyl, qhov pom tseeb dua cov nyhuv retarding. L. Semitz et al. ntseeg tias cellulose ether molecules feem ntau yog adsorbed ntawm cov khoom siv dej xws li C - S - H thiab Ca(OH) 2, thiab tsis tshua muaj adsorbed ntawm clinker thawj cov zaub mov. Ua ke nrog SEM tsom xam ntawm cov cement hydration txheej txheem, nws pom tau hais tias cellulose ether muaj tej yam retarding nyhuv, thiab siab dua cov ntsiab lus ntawm cellulose ether, qhov ntau pom tseeb cov nyhuv retarding ntawm complex zaj duab xis txheej nyob rau hauv thaum ntxov hydration ntawm cement, yog li ntawd pom tseeb dua cov nyhuv retarding.

2.4 Flexural zog thiab compressive zog

Feem ntau, lub zog yog ib qho ntawm cov kev ntsuas tseem ceeb ntawm cov cement-based cementitious cov ntaub ntawv kho cov nyhuv ntawm cov khoom sib tov. Ntxiv nrog rau kev ua haujlwm siab, nws tus kheej-leveling mortar yuav tsum muaj qee yam compressive zog thiab flexural zog. Nyob rau hauv txoj kev tshawb no, 7 thiab 28 hnub compressive zog thiab flexural zog ntawm mortar dawb paug tov nrog cellulose ether raug kuaj.

Nrog rau qhov nce ntawm cellulose ether cov ntsiab lus, mortar compressive zog thiab flexural zog yog txo nyob rau hauv txawv amplitude, cov ntsiab lus yog me me, lub zog ntawm lub zog tsis pom tseeb, tab sis nrog cov ntsiab lus ntawm ntau tshaj 0.02%, lub zog poob tus nqi loj hlob yog pom tseeb. , yog li ntawd, nyob rau hauv kev siv ntawm cellulose ether los txhim kho mortar dej tuav, tab sis kuj coj mus rau hauv tus account qhov kev hloov ntawm lub zog.

Ua rau mortar compressive thiab flexural zog poob. Nws tuaj yeem txheeb xyuas los ntawm cov hauv qab no. Ua ntej ntawm tag nrho cov, thaum ntxov lub zog thiab ceev hardening cement tsis tau siv nyob rau hauv txoj kev tshawb no. Thaum cov mortar qhuav tau tov nrog dej, qee cov cellulose ether roj hmab hmoov hmoov tau ua ntej adsorbed rau ntawm qhov chaw ntawm cov cement hais los ua ib zaj duab xis latex, uas ncua cov dej ntawm cov cement thiab txo lub zog thaum ntxov ntawm cov cement matrix. Thib ob, txhawm rau simulate qhov chaw ua haujlwm ntawm kev npaj tus kheej-leveling mortar rau ntawm qhov chaw, txhua qhov qauv hauv txoj kev tshawb no tsis raug kev vibration hauv cov txheej txheem ntawm kev npaj thiab molding, thiab cia siab rau nws tus kheej qhov hnyav leveling. Vim cov dej muaj zog tuav kev ua tau zoo ntawm cellulose ether hauv mortar, ntau qhov pores tau tso rau hauv matrix tom qab mortar hardening. Qhov nce ntawm porosity hauv mortar kuj yog ib qho laj thawj tseem ceeb rau kev txo qis ntawm compressive thiab flexural zog ntawm mortar. Tsis tas li ntawd, tom qab ntxiv cellulose ether rau hauv mortar, cov ntsiab lus ntawm saj zawg zog polymer nyob rau hauv lub pores ntawm mortar nce. Thaum lub matrix raug nias, cov polymer hloov tau yooj yim yog qhov nyuaj los ua lub luag haujlwm txhawb nqa, uas tseem cuam tshuam rau lub zog ua haujlwm ntawm matrix rau qee yam.

2.5 Bonding zog

Cellulose ether muaj txiaj ntsig zoo rau kev sib txuas cov cuab yeej ntawm mortar thiab yog siv dav hauv kev tshawb fawb thiab kev npaj ntawm tus kheej-leveling mortar.

Thaum cov ntsiab lus ntawm cellulose ether nyob nruab nrab ntawm 0.02% thiab 0.10%, daim ntawv cog lus lub zog ntawm mortar yog pom tseeb, thiab lub zog ntawm daim ntawv cog lus ntawm 28 hnub yog ntau dua li ntawm 7 hnub. Cellulose ether cov ntawv kaw cov yeeb yaj kiab polymer, uas yog qhov ua kom muaj dej xis ntawm cov cement, yog li los txhim kho txoj hlua khi ntawm lub zog tom qab hardening. Nyob rau tib lub sijhawm, tus nqi tsim nyog ntawm cellulose ether txhim kho cov yas thiab hloov pauv ntawm cov tshuaj khib nyiab, txo qhov rigidity ntawm kev hloov chaw ntawm mortar thiab substrate interface, txo qis kev ntxhov siab ntawm qhov cuam tshuam, thiab txhim kho cov txiaj ntsig kev sib txuas ntawm mortar thiab substrate hauv ib qho degree. Vim muaj cov cellulose ether nyob rau hauv cov cement slurry, ib qho tshwj xeeb interfacial hloov chaw thiab interfacial txheej yog tsim ntawm mortar hais thiab hydration khoom. Cov txheej txheej interfacial no ua rau thaj chaw hloov pauv hloov pauv hloov pauv tau yooj yim dua thiab tsis nruj, yog li cov mortar muaj zog sib txuas.

3. Kev xaus thiab kev sib tham

Cellulose ether tuaj yeem txhim kho cov dej tuav ntawm tus kheej-leveling mortar. Nrog rau qhov nce ntawm cov cellulose ether, cov dej khaws cia ntawm mortar yog maj mam txhim kho, thiab cov tshuaj khib nyiab fluidity thiab lub sij hawm teeb tsa raug txo rau qee yam. Kev tuav dej ntau dhau yuav ua rau kom cov porosity ntawm hardened slurry, uas yuav ua rau compressive thiab flexural zog ntawm hardened mortar tau pom tseeb poob. Hauv txoj kev tshawb no, lub zog poob qis thaum qhov ntau npaum li ntawm 0.02% thiab 0.04%, thiab qhov ntau ntawm cov cellulose ether, qhov pom tseeb dua cov nyhuv retarding. Yog li ntawd, thaum siv cellulose ether, nws tseem yuav tsum tau ua tib zoo xav txog cov khoom ntawm tus kheej-leveling mortar, tsim nyog xaiv ntawm ntau npaum li cas thiab cov synergistic nyhuv ntawm nws thiab lwm yam ntaub ntawv tshuaj.

Kev siv cov cellulose ether tuaj yeem txo lub zog compressive thiab flexural lub zog ntawm cov cement slurry, thiab txhim kho kev sib raug zoo ntawm mortar. Kev soj ntsuam ntawm cov laj thawj ntawm qhov kev hloov ntawm lub zog, feem ntau yog tshwm sim los ntawm kev hloov ntawm cov khoom siv micro thiab cov qauv, ntawm ib sab, cellulose ether roj hmab hmoov hmoov ua ntej adsorbed rau saum npoo ntawm cov cement hais, tsim cov latex zaj duab xis, ncua lub hydration ntawm cement, uas yuav ua rau poob ntawm lub zog thaum ntxov ntawm slurry; Ntawm qhov tod tes, vim yog cov yeeb yaj kiab tsim cov nyhuv thiab cov dej tuav cov nyhuv, nws yog qhov tsim nyog rau kev ua tiav cov dej ntawm cov cement thiab kev txhim kho ntawm daim ntawv cog lus. Tus kws sau ntawv ntseeg tias ob hom kev hloov pauv lub zog no feem ntau muaj nyob rau hauv qhov txwv ntawm lub sijhawm teeb tsa, thiab kev nce qib thiab ncua sijhawm ntawm qhov txwv no yuav yog qhov tseem ceeb uas ua rau muaj qhov loj ntawm ob hom ntawm lub zog. Ib qho kev tshawb fawb ntau ntxiv thiab kev tshawb fawb txog qhov tseem ceeb no yuav ua rau muaj kev tswj xyuas zoo dua thiab kev soj ntsuam ntawm cov txheej txheem dej ntawm cov khoom cementified hauv slurry. Nws yog qhov pab tau los kho tus nqi ntawm cellulose ether thiab kho lub sijhawm raws li qhov xav tau ntawm cov khoom siv tshuaj khib nyiab, txhawm rau txhim kho kev ua haujlwm ntawm mortar.