Npaj-mixed mortar yog muab faib ua ntub-sib xyaw mortar thiab qhuav-siv mortar raws li txoj kev tsim khoom.Qhov 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.
Tus neeg saib xyuas huab cua qhia txog ntau cov npuas me me rau hauv mortar, uas txhim kho kev ua haujlwm ntawm cov mortar, txo qhov kev tiv thaiv thaum lub sij hawm siv thiab txau, thiab txo qhov tshwm sim ntawm clogging;qhov sib ntxiv ntawm cov cua-entraining tus neeg saib xyuas txo cov tensile daim ntawv cog lus lub zog ntawm mortar Performance, raws li tus nqi ntawm mortar nce, qhov poob ntawm tensile daim ntawv cog lus lub zog kev ua tau zoo nce;tus neeg saib xyuas huab cua txhim kho cov ntsuas kev ua tau zoo xws li tshuaj khib nyiab sib xws, 2h qhov tsis sib xws ntawm qhov poob thiab cov dej tuav tus nqi, thiab txhim kho cov tshuaj tsuag thiab cov twj tso kua mis kev ua tau zoo ntawm cov khoom siv tshuaj txau mortar, ntawm qhov tod tes, nws ua rau poob ntawm mortar compressive zog thiab daim ntawv cog lus. zog.
Cov kev tshawb fawb qhia tau hais tias yam tsis xav txog cov txiaj ntsig ntawm cellulose ether, qhov nce ntawm huab cua nkag mus rau cov ntsiab lus tuaj yeem txo qhov ntub dej ntawm cov khoom sib xyaw ua ke, cov ntsiab lus ntawm cov khoom cua thiab qhov sib xws ntawm mortar yuav nce zoo heev, thiab cov dej tuav tau thiab compressive zog yuav txo;Kev tshawb fawb txog kev hloov pauv ntawm cov mortar tov nrog cellulose ether thiab air-entraining tus neeg saib xyuas pom tau hais tias tom qab sib tov huab cua-entraining tus neeg saib xyuas thiab cellulose ether, adaptability ntawm ob yuav tsum tau xav txog.Cellulose ether tej zaum yuav ua rau qee cov cua nkag mus ua tsis tiav, yog li ua rau cov dej khib nyiab txo qis.
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.Qhov sib ntxiv ntawm tus neeg saib xyuas huab cua tuaj yeem ua rau nce tus nqi ntawm cov tshuaj khib nyiab, thiab ntxiv cov shrinkage txo tus neeg sawv cev tuaj yeem txo qis tus nqi ntawm cov 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.Cov emulsion tsim los ntawm cov tshuaj txuas ntxiv latex hauv cov cement mortar tsim cov qauv duab polymer hauv cov tshuaj khib nyiab, uas tuaj yeem txhim kho lub peev xwm ntawm cov cement mortar los tiv thaiv kev puas tsuaj.
Redispersible latex hmoov tuaj yeem txhim kho qhov elasticity thiab toughness ntawm cov khoom, txhim kho qhov kev ua tau zoo ntawm cov khoom sib xyaw tshiab, thiab muaj qee yam dej txo cov nyhuv.Nws pab neeg tshawb nrhiav cov txiaj ntsig ntawm kev kho qhov system ntawm lub zog tensile lub zog ntawm mortar.
Cov txiaj ntsig kev tshawb fawb pom tau hais tias thaum tus nqi hloov pauv roj hmab hmoov yog nyob rau hauv thaj tsam ntawm 1.0% mus rau 1.5%, cov khoom ntawm cov qib sib txawv ntawm cov roj hmab hmoov yog 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.Kev sib xyaw 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 kev sib raug zoo ntawm cov mortar, txo cov voids ntawm mortar, thiab txhim kho kev ua haujlwm ntawm mortar.
Nyob rau hauv txoj kev tshawb no, qhov ruaj khov txiv qaub-xuab zeb piv yog 1: 2.5, qhov sib xws yog (70 ± 5) hli, thiab cov hmoov roj hmab tau xaiv li 0-3% ntawm cov txiv qaub-xuab zeb loj.Cov kev hloov pauv hauv cov khoom siv microscopic ntawm cov mortar hloov kho ntawm 28 hnub tau soj ntsuam los ntawm SEM, thiab cov txiaj ntsig tau pom tias ntau dua cov ntsiab lus ntawm redispersed latex hmoov, qhov txuas ntxiv ntawm cov yeeb yaj kiab polymer tsim rau ntawm qhov chaw ntawm cov khoom mortar hydration, thiab cov ntaub ntawv ntau dua. zoo dua qhov kev ua tau zoo ntawm mortar.
Cov kev tshawb fawb tau pom tias tom qab nws sib xyaw nrog cov cement mortar, cov khoom siv polymer thiab cov cement yuav coagulate los ua ib txheej txheej nrog ib leeg, thiab cov qauv ua tiav network yuav raug tsim thaum lub sij hawm hydration txheej txheem, yog li txhim kho lub zog tensile thiab kev tsim kho. ntawm thermal rwb thaiv tsev mortar.kev ua tau zoo.
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.Cao Chun et al] tau kawm txog cov nyhuv ntawm HJ-C2 thickened hmoov ntawm kev ua tau zoo ntawm cov hmoov sib tov qhuav sib xyaw, thiab cov txiaj ntsig tau pom tias cov hmoov thickened tsis tshua muaj txiaj ntsig rau qhov sib xws thiab 28d compressive zog ntawm qhuav-sib xyaw mortar, thiab muaj me ntsis cuam tshuam rau delamination ntawm mortar Muaj kev txhim kho zoo dua.Nws tau kawm txog 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, txo cov compressive zog ntawm mortar, thiab kev koom ua ke ntawm cellulose ether thiab inorganic ntxhia cov ntaub ntawv ua rau compressive thiab flexural zog ntawm mortar txo;Cov khoom muaj feem cuam tshuam rau qhov ua tau zoo ntawm cov tshuaj khib nyiab qhuav, uas ua rau kom lub shrinkage ntawm mortar.Wang Ju et al.tau kawm txog kev cuam tshuam ntawm bentonite thiab cellulose ether ntawm ntau yam kev ua tau zoo ntawm cov khoom sib xyaw npaj txhij.Nyob rau hauv cov xwm txheej ntawm kev ua kom zoo mortar kev ua tau zoo, nws tau txiav txim siab tias qhov kev pom zoo ntawm bentonite yog li 10kg / m3, thiab qhov sib piv ntawm cellulose ether yog qhov siab.Qhov kev pom zoo yog 0.05% ntawm tag nrho cov khoom siv cementitious.Nyob rau hauv qhov piv txwv no, cov hmoov sib tov nrog ob qho tib si muaj txiaj ntsig zoo rau kev ua tiav ntawm cov 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 saib xyuas 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.Cellulose ether plays huab cua-entraining nyhuv thiab txhim kho kev ua hauj lwm 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 uas tuaj yeem txhim kho kev ua haujlwm ntawm cov tshuaj khib nyiab;kev tshawb fawb Thaum lub sij hawm tus txheej txheem, nws kuj tau pom tias cov ntsiab lus ntawm cellulose ether yuav tsum tsis txhob siab dhau.Yog tias nws siab dhau lawm, huab cua cov ntsiab lus ntawm mortar yuav nce ntxiv, ua rau txo qis, tsis muaj zog thiab cuam tshuam rau qhov zoo ntawm mortar.Cov kev tshawb fawb tau pom tias qhov sib ntxiv ntawm cellulose ether ua rau cov dej khaws cia ntawm mortar, thiab tib lub sij hawm muaj cov nyhuv tseem ceeb ntawm cov tshuaj khib nyiab.Cellulose ether tuaj yeem txo qhov ntom ntawm cov tshuaj khib nyiab sib xyaw, ua kom lub sijhawm teem sijhawm, thiab txhim kho lub zog flexural thiab compressive.txo.Cellulose ether thiab hmoov txhuv nplej siab ether yog ob feem ntau siv admixtures rau kev tsim mortar.
Txawm li cas los xij, vim muaj ntau yam ntawm cellulose ethers, molecular tsis sib txawv, ua rau muaj qhov sib txawv loj hauv kev ua haujlwm ntawm cov cement mortar hloov.Lub zog ntawm cement mortar hloov nrog cellulose ether nrog siab viscosity yog tsawg dua.Thaum cov ntsiab lus ntawm cellulose ether nce, lub zog compressive ntawm cement slurry qhia tau hais tias ib qho kev txo qis thiab nws thiaj li stabilizing, thaum lub zog flexural qhia tau hais tias nce, txo qis, ruaj khov thiab ruaj khov.Kev hloov pauv me ntsis ntxiv.
Post lub sij hawm: Feb-02-2023