Focus on Cellulose ethers

Kawm txog kev sib xyaw ua ke rau cov khoom sib xyaw ua ke

Npaj-mixed mortar yog muab faib ua ntub-sib xyaw mortar thiab qhuav-siv mortar raws li txoj kev tsim khoom. Cov sib xyaw ntub dej sib xyaw nrog dej yog hu ua ntub-sib xyaw mortar, thiab cov khoom sib xyaw ua los ntawm cov ntaub ntawv qhuav hu ua qhuav-mixed mortar. Muaj ntau cov ntaub ntawv raw koom nrog hauv kev npaj sib xyaw mortar. Ntxiv nrog rau cov ntaub ntawv cementitious, aggregates, thiab ntxhia admixtures, admixtures yuav tsum tau ntxiv los txhim kho nws cov yas, dej tuav, thiab sib xws. Muaj ntau hom admixtures rau npaj-siv mortar, uas yuav muab faib ua cellulose ether, starch ether, redispersible latex hmoov, bentonite, thiab lwm yam los ntawm cov tshuaj muaj pes tsawg leeg; Nws tuaj yeem muab faib ua tus neeg saib xyuas huab cua, stabilizer, anti-cracking fiber, Retarder, accelerator, dej reducer, dispersant, thiab lwm yam.

1 Common admixtures rau npaj-mixed mortar

1.1 Air-entraining agent

Cov huab cua-entraining tus neeg sawv cev yog ib tug active neeg sawv cev, thiab ntau hom muaj xws li rosin resins, alkyl thiab alkyl aromatic hydrocarbon sulfonic acids, thiab lwm yam. Muaj pawg hydrophilic thiab hydrophobic pawg nyob rau hauv cov huab cua-entraining agent molecule. Thaum tus neeg saib xyuas huab cua ntxiv rau hauv mortar, pawg hydrophilic ntawm huab cua-entraining tus neeg saib xyuas molecule yog adsorbed nrog cov cement hais, thaum pawg hydrophobic txuas nrog cov npuas me me. Thiab sib npaug sib npaug hauv cov tshuaj khib nyiab, txhawm rau ncua cov txheej txheem dej thaum ntxov ntawm cov cement, txhim kho cov dej khaws cia ntawm cov mortar, txo qhov poob ntawm qhov sib xws, thiab tib lub sijhawm, cov npuas me me tuaj yeem ua lub luag haujlwm lubricating, txhim kho lub pumpability thiab sprayability ntawm mortar.

Cov nyhuv ntawm cov cua-entraining tus neeg saib xyuas ntawm kev ua tau zoo ntawm cov khoom sib xyaw ua ke ntawm cov tshuaj txau cov tshuaj khib nyiab, txoj kev tshawb fawb pom tias: tus neeg saib xyuas huab cua tau nthuav tawm ntau cov pa npuas me me rau hauv mortar, uas txhim kho kev ua haujlwm ntawm mortar, txo qhov tiv thaiv thaum siv thiab txau, thiab txo qhov clogging Phenomenon; qhov sib ntxiv ntawm huab cua-entraining tus neeg saib xyuas txo cov tensile daim ntawv cog lus lub zog kev ua tau zoo ntawm mortar, thiab qhov poob ntawm tensile daim ntawv cog lus lub zog kev ua tau zoo ntawm mortar nce nrog nce ntawm cov ntsiab lus; huab cua-entraining tus neeg saib xyuas txhim kho qhov sib xws, 2h qhov tsis sib xws poob tus nqi thiab cov dej khaws cia ntawm mortar Tus nqi thiab lwm yam kev ntsuas kev ua tau zoo txhim kho cov tshuaj tsuag thiab kev ua haujlwm ntawm cov khoom siv tshuaj txau mortar, ntawm qhov tod tes, nws ua rau poob ntawm lub zog compressive thiab kev sib txuas. lub zog ntawm lub mortar.

Kev cuam tshuam ntawm peb qhov kev lag luam muaj nyob rau hauv huab cua-entraining neeg sawv cev ntawm npaj-mixed mortar. Cov kev tshawb fawb qhia tau hais tias yam tsis tau xav txog cov txiaj ntsig ntawm cellulose ether, qhov nce ntawm tus nqi ntawm cov huab cua nkag tau tuaj yeem txo qhov ntub dej ntawm cov mortar npaj txhij, thiab cov ntsiab lus ntawm mortar Cov huab cua ntim thiab sib xws tau nce zoo heev, thaum lub dej tuav tus nqi thiab compressive zog yog txo; thiab los ntawm kev kawm txog kev hloov pauv ntawm cov mortar tov nrog cellulose ether thiab air-entraining tus neeg saib xyuas, nws pom tau hais tias kev hloov ntawm ob yuav tsum tau txiav txim siab tom qab cov huab cua nkag thiab cellulose ether sib xyaw. Cov cellulose ether tuaj yeem ua rau qee cov cua nkag mus ua tsis tiav, yog li txo cov dej tuav ntawm cov tshuaj khib nyiab.

Ib qho kev sib xyaw ntawm huab cua-entraining tus neeg saib xyuas, shrinkage txo tus neeg saib xyuas thiab qhov sib tov ntawm ob qho tib si muaj qee yam cuam tshuam rau cov khoom ntawm mortar. Wang Quanlei pom tias qhov sib ntxiv ntawm huab cua nkag mus rau hauv lub tshuab ua kom lub ntsws ntawm cov mortar, thiab ntxiv cov shrinkage txo tus neeg sawv cev ua rau txo qis tus nqi ntawm mortar. Ob leeg tuaj yeem ncua kev tawg ntawm lub nplhaib mortar. Thaum ob qho tib si sib xyaw, qhov shrinkage tus nqi ntawm lub mortar tsis hloov ntau, thiab qhov tawg kuj yog txhim kho.

1.2 Redispersible latex hmoov

Redispersible latex hmoov yog ib feem tseem ceeb ntawm niaj hnub prefabricated qhuav hmoov mortar. Nws yog cov dej-soluble organic polymer uas tsim los ntawm high-molecular polymer emulsion los ntawm kev kub thiab siab siab, tshuaj tsuag kom qhuav, kho deg thiab lwm yam txheej txheem. Roger ntseeg hais tias cov emulsion tsim los ntawm cov latex rov qab hmoov hmoov nyob rau hauv cov cement mortar tsim ib tug polymer zaj duab xis qauv nyob rau hauv lub mortar, uas yuav txhim kho lub peev xwm ntawm cement mortar los tiv thaiv kev puas tsuaj.

Daim ntawv thov kev tshawb fawb ntawm redispersible latex hmoov nyob rau hauv cov cement mortar qhia tau hais tias redispersible latex hmoov tuaj yeem txhim kho elasticity thiab toughness ntawm cov ntaub ntawv, txhim kho cov kev ua tau zoo ntawm cov khoom sib xyaw tshiab, thiab muaj qee yam dej txo cov nyhuv. Nws pab neeg tshawb fawb txog cov nyhuv ntawm cov txheej txheem kho ntawm lub zog tensile lub zog ntawm mortar, thiab tuaj rau tib qhov kev txiav txim siab tias cov hmoov latex dispersible ua rau cov mortar raug rau ib puag ncig ntuj resistant rau kub thiab av noo hloov. Peb thov XCT los kawm txog cov txiaj ntsig ntawm ntau hom roj hmab hmoov hauv kev hloov mortar ntawm cov qauv pore, thiab ntseeg tias piv nrog cov tshuaj khib nyiab zoo tib yam, tus naj npawb ntawm qhov thiab qhov ntim ntawm qhov hloov ntawm cov mortar loj dua.

Cov qib sib txawv thiab ntau npaum li cas ntawm cov roj hmab hloov cov hmoov tau raug xaiv los sim lawv cov kev cuam tshuam ntawm kev ua haujlwm ntawm cov dej khib nyiab. Cov txiaj ntsig kev tshawb fawb tau pom tias thaum tus nqi hloov pauv roj hmab hmoov yog nyob rau hauv thaj tsam ntawm 1.0% mus rau 1.5%, qhov kev ua tau zoo ntawm cov qib sib txawv ntawm cov hmoov roj hmab tau sib npaug. . Tom qab cov kua roj respersible latex ntxiv rau cov cement, qhov pib hydration ntawm cov cement qeeb, cov ntaub ntawv polymer qhwv cov cement hais, cov cement yog hydrated, thiab ntau yam khoom zoo tuaj. Los ntawm kev tshawb fawb, nws pom tau tias sib tov redispersible latex hmoov rau hauv cov cement mortar tuaj yeem txo cov dej, thiab cov hmoov latex thiab cov cement tuaj yeem tsim cov qauv sib txuas los txhim kho cov ntawv cog lus lub zog ntawm mortar, txo cov voids ntawm mortar, thiab txhim kho kev ua haujlwm ntawm mortar.

Kev hloov kho cov nyhuv ntawm redispersible latex hmoov ntawm cov khoom ntawm ultra-fine xuab zeb cement mortar. Nyob rau hauv kev tshawb fawb, qhov ruaj khov txiv qaub-xuab zeb piv yog 1: 2.5, qhov sib xws yog (70 ± 5) hli, thiab cov roj hmab hmoov yog xaiv li 0-3% ntawm cov txiv qaub-xuab zeb, cov kev hloov hauv cov microscopic zog ntawm cov mortar hloov ntawm 28 hnub tau soj ntsuam los ntawm SEM, thiab cov txiaj ntsig tau pom tias ntau dua cov ntsiab lus ntawm redispersible latex hmoov, qhov ntau nruam cov polymer zaj duab xis tsim nyob rau saum npoo ntawm cov khoom mortar hydration, thiab qhov kev ua tau zoo ntawm cov tshuaj mortar. lub mortar.

Lub mechanism ntawm kev txiav txim ntawm redispersible latex hmoov nyob rau hauv EPS rwb thaiv tsev mortar, kev tshawb fawb qhia tau hais tias tom qab nws yog tov nrog cement mortar, cov polymer hais thiab xis mas yuav coagulate, tsim ib tug stacked txheej nrog ib leeg, thiab tsim ib tug tiav network thaum lub sij hawm hydration txheej txheem. qauv, yog li zoo heev txhim kho lub zog tensile thiab kev tsim kho ntawm thermal rwb thaiv tsev mortar.

1.3 Thickened hmoov

Kev ua haujlwm ntawm cov hmoov thickening yog los txhim kho cov kev ua tau zoo ntawm cov tshuaj khib. Nws yog cov khoom siv tsis yog huab cua-entraining hmoov npaj los ntawm ntau yam inorganic cov ntaub ntawv, organic polymers, surfactants thiab lwm yam khoom tshwj xeeb. Thickening hmoov muaj xws li redispersible latex hmoov, bentonite, inorganic ntxhia hmoov, dej-retaining thickener, thiab lwm yam., uas muaj ib tug tej yam adsorption nyhuv ntawm lub cev dej molecules, tsis tsuas yog yuav ua rau kom qhov sib xws thiab dej tuav ntawm mortar, tab sis kuj muaj zoo compatibility nrog ntau yam cements. Qhov kev sib raug zoo tuaj yeem txhim kho kev ua haujlwm ntawm mortar. Peb tau kawm txog cov nyhuv ntawm HJ-C2 thickened hmoov rau cov khoom ntawm qhuav-mixed zoo tib yam mortar, thiab cov kev tshwm sim qhia tau hais tias cov thickened hmoov muaj me ntsis cuam tshuam rau qhov sib xws thiab 28d compressive zog ntawm qhuav-sib xyaw mortar, thiab muaj ib tug zoo. cuam ​​tshuam rau cov txheej txheem txheej txheej ntawm mortar txhim kho cov nyhuv. Kev cuam tshuam ntawm cov hmoov thickening thiab ntau yam khoom ntawm lub cev thiab cov tshuab ntsuas thiab cov kav ntev ntawm cov mortar tshiab nyob rau hauv ntau npaum li cas. Cov txiaj ntsig kev tshawb fawb pom tau hais tias kev ua haujlwm ntawm cov mortar tshiab tau txhim kho zoo heev vim qhov sib ntxiv ntawm cov hmoov thickening. Kev koom ua ke ntawm redispersible latex hmoov txhim kho lub zog flexural ntawm mortar thiab txo cov compressive zog ntawm mortar, thiab kev koom ua ke ntawm cellulose ether thiab inorganic ntxhia cov ntaub ntawv txo cov compressive thiab flexural zog ntawm mortar; Lub durability ntawm qhuav mix mortar tau raug cuam tshuam, uas ua rau kom lub shrinkage ntawm mortar. Cov txiaj ntsig ntawm kev sib xyaw ntawm bentonite thiab cellulose ether ntawm qhov ntsuas kev ua tau zoo ntawm cov khoom sib xyaw ua ke, nyob rau hauv cov xwm txheej ntawm kev ua kom zoo mortar kev ua tau zoo, nws tau txiav txim siab tias qhov zoo ntawm bentonite yog li ntawm 10kg / m3, thiab qhov zoo ntawm cellulose ether. yog kua nplaum 0.05% ntawm tag nrho cov khoom siv cementitious. Hauv qhov kev faib ua feem no, cov hmoov sib xyaw nrog ob qho tib si muaj txiaj ntsig zoo rau kev ua tiav ntawm mortar.

1.4 Cellulose Ether

Cellulose ether originated los ntawm lub ntsiab lus ntawm cov nroj tsuag cell phab ntsa los ntawm Fabkis teb Anselme Payon nyob rau hauv 1830s. Nws yog tsim los ntawm reacting cellulose los ntawm ntoo thiab paj rwb nrog caustic soda, thiab tom qab ntawd ntxiv etherification tus neeg sawv cev rau cov tshuaj tiv thaiv. Vim tias cellulose ether muaj cov dej tuav tau zoo thiab cov nyhuv thickening, ntxiv me me ntawm cellulose ether rau cement tuaj yeem txhim kho kev ua haujlwm ntawm cov khoom sib xyaw tshiab. Hauv cov khoom siv cement, feem ntau siv ntau hom cellulose ether suav nrog methyl cellulose ether (MC), hydroxyethyl cellulose ether (HEC), hydroxyethyl methyl cellulose ether (HEMC), hydroxypropyl methylcellulose Hydroxypropyl methyl cellulose ether thiab hydroxyethyl methyl cellulose feem ntau yog nquag siv.

Hydroxypropyl methyl cellulose ether (HPMC) muaj kev cuam tshuam zoo ntawm cov dej ntws, dej tuav thiab kev sib txuas lub zog ntawm tus kheej-leveling mortar. Cov txiaj ntsig tau pom tias cellulose ether tuaj yeem txhim kho cov dej khaws cia ntawm mortar, txo qhov sib xws ntawm mortar, thiab ua kom muaj txiaj ntsig zoo; Thaum tus nqi ntawm hydroxypropyl methylcellulose ether nyob nruab nrab ntawm 0.02% thiab 0.04%, lub zog ntawm mortar yog txo qis. Xu Fenlian tau tham txog kev cuam tshuam ntawm hydrocarbon propyl methyl cellulose ether ntawm kev ua haujlwm ntawm cov khoom sib xyaw ua ke los ntawm kev siv cov kev hloov pauv ntawm cov ntsiab lus ntawm hydrocarbon propyl methyl cellulose ether. Cov txiaj ntsig tau pom tias cellulose ether plays huab cua-entraining nyhuv thiab txhim kho kev ua haujlwm ntawm mortar. Nws cov dej tuav tau txo cov stratification ntawm cov tshuaj khib thiab ua kom lub sijhawm ua haujlwm ntawm cov tshuaj khib. Nws yog ib qho khoom siv sab nraud uas tuaj yeem txhim kho qhov kev ua tau zoo ntawm cov mortar. Thaum lub sijhawm kev tshawb fawb, nws kuj tau pom tias cov ntsiab lus ntawm cellulose ether yuav tsum tsis txhob siab dhau, txwv tsis pub nws yuav ua rau muaj kev nce ntxiv hauv huab cua cov ntsiab lus ntawm mortar, uas ua rau txo qhov ntom, poob ntawm lub zog thiab ib qho kev nce ntxiv. cuam ​​tshuam rau qhov zoo ntawm mortar. Cov nyhuv ntawm cellulose ether ntawm cov khoom ntawm cov khoom sib xyaw ua ke. Cov kev tshawb fawb tau pom tias qhov sib ntxiv ntawm cellulose ether tuaj yeem txhim kho cov dej tuav ntawm lub mortar, thiab tib lub sij hawm muaj cov nyhuv tseem ceeb ntawm cov tshuaj khib nyiab. Lub cellulose ether tuaj yeem ua rau cov tshuaj khib nyiab sib xyaw kom txo qis, lub sijhawm teem sijhawm ntev, txo qis flexural thiab compressive zog. Cellulose ether thiab hmoov txhuv nplej siab ether yog ob hom admixtures feem ntau siv hauv kev tsim mortar. Cov nyhuv ntawm ob qhov sib xyaw rau hauv cov tshuaj khib nyiab qhuav ntawm kev ua haujlwm ntawm cov tshuaj khib. Cov txiaj ntsig tau pom tias kev sib xyaw ua ke ntawm ob tuaj yeem txhim kho kev sib raug zoo ntawm cov tshuaj khib nyiab.

Ntau tus kws tshawb fawb tau kawm txog kev cuam tshuam ntawm cellulose ether ntawm lub zog ntawm cov cement mortar, tab sis vim muaj ntau yam ntawm cellulose ether, cov kev ntsuas molecular kuj txawv, ua rau muaj qhov sib txawv loj hauv kev ua haujlwm ntawm cov cement mortar. Cov nyhuv ntawm viscosity thiab ntau npaum ntawm cellulose ether ntawm cov khoom siv ntawm cov cement slurry. Cov txiaj ntsig tau pom tias lub zog ntawm cov cement mortar hloov nrog cellulose ether nrog cov viscosity siab yog tsawg, thiab lub zog compressive ntawm cov cement slurry qhia tau hais tias muaj kev nce ntau ntawm cov cellulose ether. Qhov sib txawv ntawm kev txo qis thiab nws thiaj li ruaj khov, thaum lub zog flexural pom ib qho kev hloov ntawm kev nce, txo qis, ruaj khov thiab nce me ntsis.

2 Epilogue

(1) Kev tshawb fawb ntawm cov khoom sib xyaw tseem txwv rau kev tshawb nrhiav kev sim, thiab kev cuam tshuam ntawm kev ua haujlwm ntawm cov ntaub ntawv cement-based tsis muaj qhov tob theoretical kev txhawb nqa. Tseem muaj qhov tsis muaj qhov ntsuas ntau ntawm qhov cuam tshuam ntawm qhov sib ntxiv ntawm cov khoom sib xyaw ntawm cov khoom siv molecular ntawm cov cement-based, kev hloov pauv ntawm kev sib txuas ntawm lub zog, thiab cov txheej txheem hydration.

(2) Cov nyhuv ntawm cov tshuaj sib tov yuav tsum tau qhia hauv daim ntawv thov engineering. Tam sim no, ntau qhov kev ntsuam xyuas tseem txwv rau kev soj ntsuam hauv chav kuaj. Ntau hom phab ntsa substrates, deg roughness, dej nqus, thiab lwm yam. muaj cov kev cai sib txawv ntawm lub cev ntsuas ntawm cov khoom sib xyaw ua ke. Lub caij sib txawv, qhov kub thiab txias, cua ceev, lub zog ntawm cov tshuab siv thiab kev khiav hauj lwm, thiab lwm yam, tag nrho ncaj qha cuam tshuam rau cov khoom sib xyaw ua ntej. Cov nyhuv ntawm kev sib xyaw mortar. Txhawm rau kom ua tiav cov txiaj ntsig zoo hauv kev tsim vaj tsev, cov khoom sib xyaw ua ke yuav tsum muaj ntau haiv neeg thiab tus kheej, thiab kev tsim cov kab ntau lawm thiab cov nqi tsim nyog ntawm lub tuam txhab yuav tsum tau txiav txim siab tag nrho, thiab kev tshuaj xyuas ntawm cov qauv kuaj yuav tsum tau nqa. tawm, thiaj li ua kom tiav qib siab tshaj plaws ntawm optimization.


Post lub sij hawm: Nov-22-2022
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