Cellulose ether hloov cov cement slurry

Cov txiaj ntsig ntawm cov qauv sib txawv ntawm cov tsis-ionic cellulose ether ntawm cov qauv pore ntawm cov cement slurry tau kawm los ntawm kev ua tau zoo ntawm kev ntsuas kev ua haujlwm thiab kev soj ntsuam macroscopic thiab microscopic pore qauv. Cov txiaj ntsig tau pom tias cov nonionic cellulose ether tuaj yeem ua rau cov porosity ntawm cov cement slurry. Thaum lub viscosity ntawm non-ionic cellulose ether hloov slurry zoo ib yam, lub porosity ntawmhydroxyethyl cellulose ether(HEC) hloov slurry yog me dua li ntawm hydroxypropyl methyl cellulose ether (HPMC) thiab methyl cellulose ether (MC) hloov slurry. Qhov qis dua qhov viscosity / txheeb ze molecular hnyav ntawm HPMC cellulose ether nrog cov ntsiab lus zoo sib xws, qhov me dua qhov porosity ntawm nws cov cement slurry. Non-ionic cellulose ether tuaj yeem txo qhov nro ntawm cov kua theem thiab ua rau cov cement slurry yooj yim tsim npuas. Non-ionic cellulose ether molecules yog directionally adsorbed ntawm cov pa roj-kua interface ntawm cov npuas, uas kuj ua rau kom cov viscosity ntawm cov cement slurry theem thiab txhim khu lub peev xwm ntawm cov cement slurry kom stabilize cov npuas.

Cov lus tseem ceeb:nonionic cellulose ether; cement slurry; Pore ​​qauv; Molecular qauv; Ntog nro; viscosity

Nonionic cellulose ether (tom qab no hu ua cellulose ether) muaj cov thickening zoo heev thiab tuav dej, thiab yog dav siv nyob rau hauv qhuav mix mortar, nws tus kheej-compacting qhob thiab lwm yam tshiab cement-based cov ntaub ntawv. Cellulose ethers siv hauv cov khoom siv cement feem ntau suav nrog methyl cellulose ether (MC), hydroxypropyl methyl cellulose ether (HPMC), hydroxyethyl methyl cellulose ether (HEMC) thiab hydroxyethyl cellulose ether (HEC), ntawm cov HPMC thiab HEMC yog cov kev siv ntau tshaj plaws. .

Cellulose ether tuaj yeem cuam tshuam qhov pore qauv ntawm cov cement slurry. Pegchez li al. cement slurry. Ntxiv mus, rau hardened cement slurry, Qhov pore loj faib ntawm qhov hnyav molecular HEC hloov cement slurry zoo ib yam li cov cement slurry. Tag nrho cov pore ntim ntawm qhov hnyav molecular hnyav HEC hloov cov cement slurry yog siab dua li cov cement slurry, tab sis qis dua li ntawm HPMC hloov cov cement slurry nrog roughly tib qhov sib xws. Los ntawm SEM kev soj ntsuam, Zhang et al. pom tias HEMC tuaj yeem ua kom cov pores ntau ntxiv nrog txoj kab uas hla ntawm 0.1 hli hauv cov cement mortar. Lawv kuj pom los ntawm kev kuaj mercury uas HEMC tuaj yeem ua kom tag nrho cov pore ntim thiab qhov nruab nrab pore txoj kab uas hla ntawm cov cement slurry, uas ua rau muaj qhov loj ntawm cov pores loj nrog txoj kab uas hla ntawm 50nm ~ 1μm thiab cov pores loj nrog txoj kab uas hla ntau dua. mas 1m. Txawm li cas los xij, tus naj npawb ntawm cov pores nrog txoj kab uas hla tsawg dua 50nm tau txo qis. Saric-Coric et al. ntseeg tias cellulose ether yuav ua rau cov cement slurry ntau ntxeem tau thiab ua rau kom cov macropores nce. Jenni et al. kuaj qhov kev ua tau zoo thiab txiav txim siab tias qhov pore ntim feem ntawm HEMC hloov cov cement mortar yog kwv yees li 20%, thaum cov cement mortar ntshiab tsuas muaj cua me me xwb. Silva et al. pom tias ntxiv rau ob lub ncov ntawm 3.9 nm thiab 40 ~ 75nm raws li cov cement slurry, kuj tseem muaj ob lub ncov ntawm 100 ~ 500nm thiab ntau dua 100μm los ntawm mercury txhaj tshuaj. Ma Baoguo et al. pom tias cellulose ether nce tus naj npawb ntawm cov pores zoo nrog txoj kab uas hla tsawg dua 1μm thiab cov pores loj nrog txoj kab uas hla ntau dua 2μm hauv cov cement mortar los ntawm mercury txhaj tshuaj. Raws li yog vim li cas cellulose ether nce porosity ntawm cov cement slurry, feem ntau ntseeg tau tias cellulose ether muaj cov dej num saum npoo av, yuav ua kom muaj huab cua thiab dej sib txuas, tsim cov yeeb yaj kiab, thiaj li ua kom cov npuas hauv cov cement slurry.

Los ntawm kev txheeb xyuas cov ntaub ntawv saum toj no, nws tuaj yeem pom tias cov txiaj ntsig ntawm cellulose ether ntawm cov qauv pore ntawm cov khoom siv cement tau txais kev saib xyuas zoo. Txawm li cas los xij, muaj ntau hom cellulose ether, tib hom cellulose ether, nws cov txheeb ze molecular hnyav, pab pawg neeg cov ntsiab lus thiab lwm yam molecular qauv tsis kuj txawv heev, thiab domestic thiab txawv teb chaws soj ntsuam ntawm cellulose ether xaiv tsuas yog txwv rau lawv daim ntawv thov. teb, tsis muaj kev sawv cev, cov lus xaus yog inevitable "overgeneralization", yog li ntawd qhov kev piav qhia ntawm cellulose ether mechanism tsis tob txaus. Hauv daim ntawv no, cov nyhuv ntawm cellulose ether nrog cov qauv sib txawv ntawm cov qauv pore ntawm cov cement slurry tau kawm los ntawm kev kuaj pom tseeb thiab macroscopic thiab microscopic pore qauv soj ntsuam.

1. Kev xeem

1.1 Cov khoom siv raw

Cov cement yog P·O 42.5 zoo tib yam Portland cement tsim los ntawm Huaxin Cement Co., LTD., uas cov tshuaj muaj pes tsawg leeg tau ntsuas los ntawm AXIOS Ad-Vanced wavelength dispersion-hom X-ray fluorescence spectrometer (PANa — lytical, Netherlands), thiab cov theem muaj pes tsawg leeg tau kwv yees los ntawm txoj kev Bogue.

Cellulose ether xaiv plaub hom kev lag luam cellulose ether, raws li methyl cellulose ether (MC), hydroxypropyl methyl cellulose ether (HPMC1, HPMC2) thiab hydroxyethyl cellulose ether (HEC), HPMC1 molecular qauv thiab HPMC2 zoo sib xws, tab sis cov viscosity tsawg dua HPMC2. , Qhov ntawd yog, qhov txheeb ze molecular loj ntawm HPMC1 tsawg dua li ntawm HPMC2. Vim tias cov khoom zoo sib xws ntawm hydroxyethyl methyl cellulose ether (HEMc) thiab HPMC, HEMCs tsis raug xaiv hauv txoj kev tshawb no. Txhawm rau kom tsis txhob muaj kev cuam tshuam ntawm cov ntsiab lus ntawm cov ntsiab lus ntawm kev ntsuas, tag nrho cov cellulose ethers tau ci ntawm 98 ℃ rau 2h ua ntej siv.

Lub viscosity ntawm cellulose ether raug kuaj los ntawm NDJ-1B teb viscosimeter (Shanghai Changji Company). Kev ntsuas kev daws teeb meem (qhov loj ntawm cellulose ether rau dej) yog 2.0%, qhov kub yog 20 ℃, thiab kev sib hloov yog 12r / min. Qhov nro ntawm cellulose ether tau sim los ntawm txoj kev nplhaib. Qhov ntsuas ntsuas yog JK99A tsis siv neeg tensiometer (Shanghai Zhongchen Company). Qhov concentration ntawm cov tshuaj ntsuam xyuas yog 0.01% thiab qhov kub yog 20 ℃. Cellulose ether pawg ntsiab lus yog muab los ntawm cov chaw tsim khoom.

Raws li cov viscosity, qhov nro thiab cov ntsiab lus ntawm cov cellulose ether, thaum cov tshuaj concentration yog 2.0%, viscosity piv ntawm HEC thiab HPMC2 tov yog 1: 1.6, thiab viscosity ratio ntawm HEC thiab MC tov yog 1: 0.4, tab sis Hauv qhov kev sim no, cov dej-cement piv yog 0.35, qhov siab tshaj plaws cement piv yog 0.6%, qhov loj ntawm cellulose ether rau dej yog li 1.7%, tsawg dua 2.0%, thiab cov nyhuv synergistic ntawm cement slurry ntawm viscosity, viscosity sib txawv ntawm HEC, HPMC2 lossis MC hloov cov cement slurry yog me me.

Raws li qhov viscosity, qhov nro ntawm qhov chaw thiab cov ntsiab lus ntawm cellulose ether, qhov nro ntawm txhua cellulose ether yog txawv. Cellulose ether muaj ob pawg hydrophilic (hydroxyl thiab ether pawg) thiab pawg hydrophobic (methyl thiab qabzib carbon nplhaib), yog ib qho surfactant. Cellulose ether sib txawv, hom thiab cov ntsiab lus ntawm hydrophilic thiab hydrophobic pawg sib txawv, ua rau muaj qhov sib txawv ntawm qhov sib txawv.

1.2 Cov txheej txheem xeem

Rau hom cement slurry tau npaj, suav nrog cov cement slurry, plaub cellulose ether (MC, HPMCl, HPMC2 thiab HEC) hloov cov cement slurry nrog 0.60% cement ratio thiab HPMC2 hloov cement slurry nrog 0.05% cement ratio. Ref, MC — 0.60, HPMCl — 0.60, Hpmc2-0.60. HEC 1-0.60 thiab hpMC2-0.05 qhia tias cov dej-cement piv yog ob qho tib si 0.35.

Cement slurry ua ntej raws li GB / T 17671 1999 "cement mortar zog test method (ISO method)" ua rau hauv 40mm × 40mm × 160mm prisms test block, nyob rau hauv cov xwm txheej ntawm 20 ℃ kaw curing 28d. Tom qab ntsuas thiab suav nws qhov pom tseeb qhov ntom ntom, nws tau tawg qhib nrog rauj me me, thiab qhov macro qhov mob ntawm qhov nruab nrab ntawm qhov ntsuas ntsuas tau pom thiab thaij duab nrog lub koob yees duab digital. Nyob rau tib lub sijhawm, cov khoom me me ntawm 2.5 ~ 5.0mm raug coj mus rau kev soj ntsuam los ntawm lub tshuab ntsuas qhov muag (HIROX peb-dimensional video microscope) thiab scanning electron microscope (JSM-5610LV).

2. Cov ntawv xeem

2.1 Pom pom qhov ntom ntom

Raws li qhov pom tseeb ntom ntom ntawm cov cement slurry hloov los ntawm cov cellulose ethers sib txawv, (1) qhov pom tseeb ntom ntom ntawm cov cement slurry yog qhov siab tshaj plaws, uas yog 2044 kg / m³; Qhov pom tseeb qhov ntom ntawm plaub hom cellulose ether hloov slurry nrog cov cement piv ntawm 0.60% yog 74% ~ 88% ntawm cov cement slurry, qhia tias cellulose ether ua rau muaj qhov porosity ntawm cement slurry. (2) Thaum qhov sib piv ntawm cov cement rau cement yog 0.60%, cov nyhuv ntawm cov cellulose ethers sib txawv ntawm cov porosity ntawm cov cement slurry txawv heev. Lub viscosity ntawm HEC, HPMC2 thiab MC hloov cov cement slurry zoo ib yam, tab sis qhov pom tseeb ntawm HEC hloov cov cement slurry yog qhov siab tshaj, qhia tias qhov porosity ntawm HEC hloov cement slurry yog me dua li ntawm HPMc2 thiab Mc hloov cement slurry nrog viscosity zoo sib xws. . HPMc1 thiab HPMC2 muaj cov ntsiab lus zoo sib xws, tab sis qhov viscosity ntawm HPMCl qis dua li ntawm HPMC2, thiab qhov pom tseeb ntawm HPMCl hloov cov cement slurry yog qhov siab dua li ntawm HPMC2 hloov cov cement slurry, uas qhia tau hais tias thaum pab pawg cov ntsiab lus zoo sib xws. , qhov qis dua qhov viscosity ntawm cellulose ether, qhov qis dua qhov porosity ntawm hloov cement slurry. (3) Thaum qhov sib piv ntawm cov cement-rau-cement tsawg heev (0.05%), qhov pom tseeb ntom ntom ntawm HPMC2-hloov cement slurry yog nyob ze rau ntawm cov cement slurry, qhia tias cov nyhuv ntawm cellulose ether ntawm porosity ntawm cov cement. slurry tsawg heev.

2.2 Macroscopic pore

Raws li cov duab ntawm cellulose ether hloov cov cement slurry coj los ntawm cov koob yees duab, cov cement slurry yog ntom heev, yuav luag tsis pom qhov pores; Plaub hom cellulose ether hloov slurry nrog 0.60% cement piv tag nrho muaj ntau macroscopic pores, qhia tias cellulose ether ua rau kom cov cement slurry porosity. Zoo ib yam li cov txiaj ntsig ntawm qhov kev ntsuam xyuas pom tseeb, cov txiaj ntsig ntawm ntau hom cellulose ether thiab cov ntsiab lus ntawm cov porosity ntawm cov cement slurry yog txawv heev. Lub viscosity ntawm HEC, HPMC2 thiab MC hloov slurry zoo ib yam, tab sis lub porosity ntawm HEC hloov slurry yog me dua li ntawm HPMC2 thiab MC hloov slurry. Txawm hais tias HPMC1 thiab HPMC2 muaj cov ntsiab lus zoo sib xws, HPMC1 hloov slurry nrog qis viscosity muaj qhov porosity me dua. Thaum cov cement-rau-cement piv ntawm HPMc2 hloov slurry tsawg heev (0.05%), tus naj npawb ntawm macroscopic pores yog me ntsis ntau dua li cov cement slurry, tab sis kuj txo qis dua li ntawm HPMC2 hloov slurry nrog 0.60% cement-rau - cement ratio.

2.3 Microscopic pore

4. Cov lus xaus

(1) Cellulose ether tuaj yeem ua kom cov porosity ntawm cov cement slurry.

(2) Cov nyhuv ntawm cellulose ether ntawm porosity ntawm cement slurry nrog cov qauv molecular tsis sib txawv: thaum lub viscosity ntawm cellulose ether hloov cement slurry zoo ib yam, lub porosity ntawm HEC hloov cement slurry yog me dua li ntawm HPMC thiab MC hloov. cement slurry; Qhov qis dua qhov viscosity / txheeb ze molecular hnyav ntawm HPMC cellulose ether nrog cov ntsiab lus zoo sib xws, qhov qis dua qhov porosity ntawm nws cov cement slurry.

(3) Tom qab ntxiv cellulose ether rau hauv cov cement slurry, qhov nro ntawm cov kua theem yog txo, kom cov cement slurry yog ib qho yooj yim los tsim npuas thiab cellulose ether molecules directional adsorption nyob rau hauv lub npuas roj-kua interface, txhim kho lub zog thiab toughness ntawm npuas kua zaj duab xis adsorption nyob rau hauv lub npuas roj-kua interface, txhim kho lub zog ntawm cov npuas kua zaj duab xis thiab ntxiv dag zog rau lub peev xwm ntawm cov tawv av nkos kom stabilize lub npuas.