Cov nyhuv ntawm Hydroxypropyl Methyl Cellulose Ether ntawm Cov Khoom Ntawm Lub Tshuab Txau Cement Mortar

Cellulose ether yog ib qho tseem ceeb additive nyob rau hauv tshuab-blasted mortar. Cov teebmeem ntawm plaub qhov sib txawv ntawm viscosities ntawm hydroxypropyl methylcellulose (HPMC) ntawm cov dej tuav, qhov ntom ntom, cov ntsiab lus ntawm cov cua, cov khoom siv kho tshuab thiab qhov pore loj faib ntawm cov tshuab-blasted mortar tau kawm. Cov kev tshawb fawb tau pom tias: HPMC tuaj yeem txhim kho cov dej khaws cia ntawm mortar, thiab cov dej tuav tau ntau dua 90% thaum tus nqi ntawm HPMC yog 0.15%. Qhov pom tseeb tshaj plaws; huab cua cov ntsiab lus ntawm mortar nce nrog qhov nce ntawm HPMC cov ntsiab lus: HPMC yuav pom tseeb txo cov khoom siv ntawm cov cement mortar, tab sis qhov sib piv ntawm mortar yuav nce; Qhov pore loj ntawm mortar yuav nce ntxiv tom qab ntxiv HPMC, Qhov feem pua ​​​​ntawm cov qhov tsis zoo thiab ntau qhov teeb meem tau nce ntau.

Cov lus tseem ceeb: mortar; hydroxypropyl methylcellulose ether; tuav dej; pore loj faib

0. Lus qhuab qhia

Nyob rau hauv xyoo tas los no, nrog kev nce qib ntawm kev lag luam thiab kev txhim kho thev naus laus zis, los ntawm kev qhia thiab txhim kho cov tshuab txau tshuab txawv teb chaws, cov cuab yeej siv tshuab txau thiab plastering tau zoo heev hauv peb lub teb chaws. Mechanical spraying mortar yog txawv ntawm cov mortar zoo tib yam, uas yuav tsum tau muaj dej tuav kev ua tau zoo, haum fluidity thiab tej yam kev tiv thaiv sagging. Feem ntau, cellulose ether yog ntxiv rau hauv mortar, cov uas hydroxypropyl methylcellulose Plain ether (HPMC) yog siv dav tshaj plaws. Lub luag haujlwm tseem ceeb ntawm HPMC hauv mortar yog: cov dej tuav tau zoo, ua kom tuab thiab viscosifying thiab rheological hloov. Txawm li cas los xij, qhov tsis txaus ntawm HPMC tsis tuaj yeem tsis quav ntsej. HPMC muaj cov nyhuv air-entraining, uas yuav ua rau muaj kev cuam tshuam sab hauv ntau dua thiab txo cov khoom siv dag zog ntawm mortar. Cov ntaub ntawv no kawm txog kev cuam tshuam ntawm HPMC ntawm cov dej tuav tus nqi, qhov ntom ntom, cov ntsiab lus ntawm huab cua thiab cov khoom siv ntawm cov tshuaj khib nyiab los ntawm cov macroscopic nam, thiab kawm txog kev cuam tshuam ntawm HPMC ntawm lub pore qauv ntawm lub mortar los ntawm microscopic nam.

1. Kev xeem

1.1 Cov khoom siv raw

Cement: lag luam muaj P·O42.5 cement, nws 28d flexural thiab compressive zog yog 6.9 thiab 48.2 MPa feem; xuab zeb: Chengde nplua dej xuab zeb, 40-100 mesh; cellulose ether: hydroxypropyl cawv ua los ntawm ib lub tuam txhab nyob rau hauv Hebei Methyl cellulose ether, dawb hmoov, nominal viscosity 40, 100, 150, 200 Pa·S: Dej: dej huv.

1.2 Test method

Raws li JGJ / T 105-2011 "Txoj Cai Kev Tsim Kho rau Kev Siv Tshuab Txau thiab Plastering", qhov sib xws ntawm cov mortar yog 80 ~ 120mm, thiab cov dej tuav tau ntau dua 90%. Hauv qhov kev sim no, qhov sib piv ntawm txiv qaub-xuab zeb yog teem rau ntawm 1: 5, qhov sib xws yog tswj ntawm (93).±2) hli, thiab cov cellulose ether yog sab nraud sib xyaw, thiab nws qhov ntau npaum li cas yog xam raws li cov cement loj. Cov khoom tseem ceeb ntawm kev xhuv ntub xws li ntub dej, cua cov ntsiab lus, thiab kev sim ua kom siv tau ntawm JGJ 70-2009 "cov ntsiab lus cua yog sim thiab suav raws li cov txoj kev ceev. Kev npaj, flexural thiab compressive zog kuaj ntawm cov qauv tau ua nrog kev siv rau GB / T 17671-1999 "Txoj hauv kev rau Kev Ntsuas Lub Zog ntawm Cement Mortar Sand (ISO Method)". Qhov pore loj tau kuaj los ntawm mercury porosimetry. Tus qauv ntawm mercury porosimeter yog AUTOPORE 9500, thiab qhov ntsuas ntau yog 5.5 nm rau 360μm. Tag nrho ntawm 4 qhov kev xeem tau ua tiav. 0, 0.1%, 0.2%, 0.3% (tus lej yog A, B, C, D).

2. Cov txiaj ntsig thiab kev tshuaj xyuas

2.1 Cov nyhuv ntawm HPMC ntawm cov dej tuav tus nqi ntawm cov cement mortar

Kev tuav dej yog hais txog lub peev xwm ntawm mortar los tuav dej. Nyob rau hauv lub tshuab sprayed mortar, ntxiv cellulose ether tuaj yeem tswj cov dej noo, txo cov ntshav, thiab ua tau raws li qhov yuav tsum tau muaj dej txaus ntawm cov khoom siv cement.

Los ntawm cov nyhuv ntawm HPMC rau cov dej tuav tus nqi ntawm mortar, nws yuav pom tau hais tias nrog nce ntawm HPMC cov ntsiab lus, cov dej tuav tus nqi ntawm mortar nce maj mam. Qhov nkhaus ntawm cellulose ethers nrog viscosities ntawm 100, 150 thiab 200 Pa·s yeej yog tib yam. Thaum cov ntsiab lus yog 0.05% mus rau 0.15%, cov dej tuav tus nqi nce linearly. Thaum cov ntsiab lus yog 0.15%, cov dej tuav tau ntau dua 93%..Tom qab 20%, qhov sib ntxiv ntawm cov dej tuav tau tiaj tus, qhia tias tus nqi ntawm HPMC yog ze rau qhov saturation. Lub zog nkhaus ntawm tus nqi ntawm HPMC nrog viscosity ntawm 40 Pa·s ntawm cov dej tuav tus nqi yog kwv yees li ib txoj kab ncaj nraim. Thaum cov nyiaj ntau dua 0.15%, cov dej tuav tus nqi ntawm cov mortar yog qhov qis dua li ntawm peb hom HPMC nrog tib tus nqi ntawm viscosity. Nws feem ntau ntseeg tau tias cov dej tuav cov txheej txheem ntawm cellulose ether yog: pawg hydroxyl ntawm cellulose ether molecule thiab oxygen atom ntawm ether daim ntawv cog lus yuav koom nrog cov dej molecule los tsim ib daim ntawv cog lus hydrogen, kom cov dej dawb ua cov dej khi. , yog li ua si cov dej tuav zoo; Nws tseem ntseeg tau hais tias kev sib tshuam ntawm cov dej molecules thiab cellulose ether molecular chains tso cai rau cov dej molecules nkag mus rau sab hauv ntawm cellulose ether macromolecular chains thiab yuav tsum muaj zog binding rog, yog li txhim kho cov dej tuav ntawm cement slurry. Kev tuav dej zoo tuaj yeem ua kom cov mortar homogeneous, tsis yooj yim rau kev sib cais, thiab tau txais kev sib xyaw ua haujlwm zoo, thaum txo cov khoom siv thiab ua rau lub neej ntawm cov tshuaj khib nyiab.

2.2 Qhov cuam tshuam ntawm HPMC rau qhov ntom ntom thiab cua cov ntsiab lus ntawm cov cement mortar

Los ntawm kev cuam tshuam ntawm cov viscosities sib txawv thiab ntau npaum li cas ntawm HPMC ntawm qhov ntom ntawm mortar, nws tuaj yeem pom tias thaum noj HPMC yog 0-0.20%, qhov ntom ntawm mortar txo qis nrog qhov nce ntawm HPMC ntau npaum li cas, los ntawm 2050 kg / m.³ mus txog 1650 kg / m³ , poob li ntawm 20%; Tom qab HPMC cov ntsiab lus siab tshaj 0.20%, qhov ntom ntom ntom ntom ntom ntom ntom ntom. Muab piv rau plaub hom HPMC nrog cov viscosities sib txawv, nws tuaj yeem pom tias qhov viscosity siab dua, qhov qis dua qhov ntom ntawm cov mortar; Qhov ntom ntom ntawm cov mortars nrog cov viscosities sib xyaw ntawm 150 thiab 200 Pa s HPMC pib sib tshooj, qhia tias vim qhov viscosity ntawm HPMC tseem nce ntxiv, qhov ntom ntawm mortar tsis txo.

Los ntawm kev cuam tshuam ntawm cov viscosities sib txawv thiab ntau npaum li cas ntawm HPMC ntawm cov ntsiab lus huab cua ntawm mortar, nws tuaj yeem pom tau tias qhov kev hloov pauv ntawm cov ntsiab lus ntawm cov mortar yog qhov txawv ntawm qhov ntom ntawm mortar. Cov huab cua ntim yuav luag nce hauv txoj kab ncaj nraim; thaum HPMC cov ntsiab lus siab tshaj 0.20%, cov ntsiab lus huab cua tsis tshua hloov, qhia tau hais tias huab cua nkag los ntawm cov tshuaj khib nyiab yog ze rau saturation. Cov huab cua-entraining nyhuv ntawm HPMC nrog viscosity ntawm 150 thiab 200 Pa·s yog ntau dua li ntawm HPMC nrog viscosity ntawm 40 thiab 100 Pa·s.

Cov huab cua-entraining nyhuv ntawm cellulose ether yog tsuas yog txiav txim los ntawm nws cov qauv molecular. Cellulose ether muaj ob pawg hydrophilic (hydroxyl, ether pawg) thiab hydrophobic pawg (methyl pawg, qabzib rings), thiab yog surfactant. , muaj kev ua haujlwm saum npoo, yog li muaj cov nyhuv cua-entraining. Ntawm qhov tod tes, cov roj nkag tau tuaj yeem ua raws li lub pob bearing hauv mortar, txhim kho kev ua haujlwm ntawm cov mortar, nce ntim, thiab nce cov zis, uas muaj txiaj ntsig zoo rau cov chaw tsim khoom. Tab sis ntawm qhov tod tes, cov nyhuv huab cua ua rau nce cov ntsiab lus ntawm cov mortar thiab cov porosity tom qab hardening, uas ua rau kom muaj teeb meem pores thiab zoo heev txo cov neeg kho tshuab zog. Txawm hais tias HPMC muaj qee yam huab cua nkag mus, nws tsis tuaj yeem hloov tus neeg saib xyuas huab cua. Tsis tas li ntawd, thaum HPMC thiab air-entraining agent siv tib lub sijhawm, tus neeg saib xyuas huab cua tuaj yeem ua tsis tiav.

2.3 Qhov cuam tshuam ntawm HPMC rau cov khoom siv ntawm cov cement mortar

Los ntawm 28d flexural zog thiab 28d compressive zog, nws tuaj yeem pom tias thaum tus nqi ntawm HPMC tsuas yog 0.05%, lub zog flexural ntawm cov tshuaj khib nyiab txo qis, uas yog li 25% qis dua li ntawm cov qauv dawb paug tsis muaj HPMC, thiab lub zog compressive tuaj yeem ncav cuag 65% ntawm cov qauv dawb xwb. 80%. Thaum cov ntsiab lus ntawm HPMC tshaj 0.20%, qhov txo qis hauv lub zog flexural thiab compressive zog ntawm cov tshuaj khib nyiab tsis pom tseeb. Lub viscosity ntawm HPMC muaj me ntsis cuam tshuam rau cov khoom siv ntawm cov tshuaj khib nyiab. HPMC nthuav qhia ntau cov pa npuas me me, thiab cov cua nkag mus rau hauv cov tshuaj khib nyiab ua rau cov porosity sab hauv thiab qhov tsis zoo ntawm cov mortar, uas ua rau muaj qhov txo qis hauv compressive zog thiab flexural zog. Lwm qhov laj thawj rau qhov txo qis hauv mortar zog yog cov dej tuav cov txiaj ntsig ntawm cellulose ether, uas ua rau cov dej hauv cov tshuaj khib nyiab, thiab cov dej loj-binder piv ua rau txo qis ntawm lub zog ntawm qhov ntsuas ntsuas. Rau cov neeg kho tshuab siv mortar, txawm hais tias cellulose ether tuaj yeem ua rau kom cov dej khaws cia ntawm cov mortar thiab txhim kho nws txoj haujlwm, yog tias cov nyiaj ntau dhau, nws yuav cuam tshuam rau cov khoom siv ntawm cov tshuaj khib nyiab, yog li kev sib raug zoo ntawm ob qho tib si yuav tsum tau ntsuas qhov tsim nyog.

Los ntawm 28-hnub folding piv, nws tuaj yeem pom tau tias nrog kev nce ntawm HPMC cov ntsiab lus, tag nrho cov folding piv ntawm cov mortar qhia tau hais tias muaj kev nce ntxiv, uas yog ib qho kev sib raug zoo. Qhov no yog vim hais tias ntxiv cellulose ether qhia ntau cov huab cua npuas, ua rau ntau yam tsis xws luag nyob rau hauv lub mortar, uas ua rau ib tug ntse txo nyob rau hauv lub compressive zog ntawm lub mortar, thiab txawm hais tias lub flexural zog kuj txo mus rau ib tug tej yam; tab sis cov cellulose ether tuaj yeem txhim kho qhov yooj yim ntawm cov tshuaj khib thiab tiv thaiv Lub zog folding yog qhov zoo, uas ua rau tus nqi qis qis. Xav txog kev nkag siab, qhov sib xyaw ua ke ntawm ob qhov ua rau muaj kev nce hauv qhov sib piv.

2.4 Cov nyhuv ntawm HPMC ntawm qhov pore loj ntawm mortar

Lub pore loj faib nkhaus ntawm plaub pawg ntawm cov qauv A, B, C thiab D tau ntsuas los ntawm mercury intrusion porosimetry.

Raws li qhov pore loj faib nkhaus, pore loj faib cov ntaub ntawv thiab ntau yam kev txheeb cais ntawm AD cov qauv, HPMC muaj kev cuam tshuam zoo rau cov qauv pore ntawm cement mortar:

(1) Tom qab ntxiv HPMC, qhov pore loj ntawm cov cement mortar nce ntau. Ntawm qhov pore loj faib nkhaus, thaj tsam ntawm daim duab txav mus rau sab xis, thiab qhov pore tus nqi sib raug rau tus nqi ncov yuav loj dua. Tsis tas li los ntawm cov ntaub ntawv txheeb cais ntawm qhov pore loj faib thiab qhov nruab nrab qhov pore loj hauv qhov kev sim ntsuas ntawm ntau yam kev txheeb cais, nws tuaj yeem pom tias qhov nruab nrab qhov pore loj ntawm cov cement mortar tom qab ntxiv HPMC yog qhov loj dua li ntawm cov qauv dawb paug, thiab hauv cov qauv nrog 0.3% ntau npaum li cas Tus nqi aperture yog 2 xaj ntawm qhov loj dua li ntawm cov qauv dawb paug.

(2) Wu Zhongwei et al. muab faib cov pores nyob rau hauv pob zeb ua rau plaub hom, uas yog harmless pores (≤20 nm), ob peb pores teeb meem (20-100 nm), teeb meem pores (100-200 nm) thiab ntau yam teeb meem pores (≥200 nm). 200 nm). Los ntawm cov ntaub ntawv pov thawj ntawm cov pore loj thiab cov txiaj ntsig ntawm ntau qhov kev txheeb cais, nws tuaj yeem pom tias tus naj npawb ntawm cov pores tsis muaj teeb meem lossis qhov tsis zoo ntawm qhov pores tau txo qis, thiab tus naj npawb ntawm cov pores teeb meem lossis ntau qhov teeb meem pores tau nce tom qab ntxiv HPMC. Qhov tsis muaj teeb meem lossis tsis muaj teeb meem qhov pores ntawm tus qauv uas tsis muaj HPMC yog kwv yees li 49.4%, thiab cov pores uas tsis muaj teeb meem los yog tsawg dua yuav raug txo qis tom qab ntxiv HPMC. Noj cov koob tshuaj ntawm 0.1% ua piv txwv, qhov tsis muaj teeb meem lossis qhov tsis zoo ntawm qhov pores raug txo los ntawm 45%. , tus naj npawb ntawm cov teeb meem pores loj dua 10μm nce 9x.

3) Qhov nruab nrab pore txoj kab uas hla, nruab nrab pore txoj kab uas hla, tshwj xeeb pore ntim thiab cov cheeb tsam tshwj xeeb tsis ua raws li txoj cai hloov nruj heev nrog rau qhov nce ntawm HPMC cov ntsiab lus, uas tej zaum yuav muaj feem xyuam rau qhov loj dispersion ntawm cov qauv xaiv hauv mercury txhaj tshuaj. Tab sis ntawm tag nrho, qhov nruab nrab pore txoj kab uas hla, qhov nruab nrab pore txoj kab uas hla thiab qhov pore ntim ntawm cov qauv sib xyaw nrog HPMC zoo li nce piv nrog cov qauv dawb paug, thaum qhov tshwj xeeb ntawm qhov chaw txo qis.

3. Cov lus xaus

(1) Cov dej tuav tus nqi ntawm cov mortar nce nrog nce ntawm HPMC cov ntsiab lus. Qhov nkhaus ntawm cellulose ether nrog viscosities ntawm 100, 150 thiab 200 Pa·S yog qhov zoo ib yam, thiab cov dej tuav tau ntau dua 93% thaum cov ntsiab lus yog 0.15%. Thaum cov ntsiab lus ntawm 40 Pa·s cellulose ether yog ntau dua 0.15%, cov dej tuav tau qis dua li ntawm peb hom viscosity HPMC.

(2) Qhov ceev ntawm mortar txo qis nrog qhov nce ntawm HPMC cov ntsiab lus, thiab cov ntsiab lus yog 0.05%. Qhov ntom ntom yog qhov pom tseeb tshaj plaws ntawm 0.20%, txog 20%; thaum cov ntsiab lus siab tshaj 0.20%, qhov ceev tsis tshua hloov; huab cua cov ntsiab lus ntawm mortar nce nrog nce ntawm HPMC cov ntsiab lus.

(3) Qhov nce ntawm HPMC cov ntsiab lus yuav pom tseeb txo cov khoom siv ntawm cov cement mortar, tab sis qhov sib npaug ntawm cov tshuaj khib nyiab yuav nce ntxiv, thiab qhov hloov pauv ntawm mortar yuav zoo dua.

(4) Tom qab ntxiv HPMC, qhov pore loj ntawm cov mortar nce ntau, thiab qhov feem pua ​​​​ntawm cov pores uas tsim kev puas tsuaj thiab ntau qhov pores puas tsuaj nce ntau. Cov qauv nrog 0.1% HPMC cov ntsiab lus txo qis txog 45% piv nrog cov qauv dawb paug uas tsis muaj lossis tsawg dua cov pores txaus ntshai, thiab tus naj npawb ntawm cov teeb meem pores loj dua 10μm nce 9x.