1. Cov yam ntxwv ntawm HPMC hauv cov mortar zoo tib yam
HPMC feem ntau yog siv los ua retarder thiab dej tuav tus neeg sawv cev hauv cement proportioning.Nyob rau hauv cov khoom sib xyaw thiab mortar, nws tuaj yeem txhim kho viscosity thiab shrinkage tus nqi, ntxiv dag zog rau lub zog cohesive, tswj cov cement teeb lub sij hawm, thiab txhim kho thawj lub zog thiab zoo li qub bending zog.Vim tias nws muaj kev ua haujlwm ntawm kev tuav dej, nws tuaj yeem txo qhov poob ntawm cov dej ntawm cov pob zeb, tsis txhob tawg ntawm ntug, thiab txhim kho adhesion thiab kev tsim kho.Tshwj xeeb hauv kev tsim kho, lub sijhawm teeb tsa tuaj yeem txuas ntxiv thiab hloov kho.Nrog rau qhov nce ntawm HPMC cov ntsiab lus, lub sijhawm teem sijhawm ntawm mortar yuav txuas ntxiv mus ntxiv;txhim kho lub machinability thiab pumpability, haum rau kev siv tshuab;txhim kho kev tsim kho kom zoo thiab muaj txiaj ntsig rau lub tsev nto Tiv thaiv huab cua ntawm cov dej-soluble ntsev.
2. Cov yam ntxwv ntawm HPMC hauv mortar tshwj xeeb
HPMC yog cov dej-txheej txheem ua haujlwm zoo rau cov hmoov qhuav mortar, uas txo cov ntshav los ntshav thiab delamination ntawm cov tshuaj khib thiab txhim kho cov cohesion ntawm mortar.Txawm hais tias HPMC me ntsis txo qhov flexural thiab compressive lub zog ntawm lub mortar, nws tuaj yeem ua rau kom lub zog tensile thiab daim ntawv cog lus lub zog ntawm mortar.Tsis tas li ntawd, HPMC tuaj yeem cuam tshuam qhov tsim ntawm cov kab nrib pleb hauv mortar thiab txo cov yas tawg qhov ntsuas ntawm mortar.Cov dej tuav ntawm mortar nce nrog nce ntawm HPMC viscosity, thiab thaum lub viscosity tshaj 100000mPa·s, cov dej tuav tsis tau nce ntau.Qhov zoo ntawm HPMC kuj muaj qee yam cuam tshuam rau cov dej tuav tus nqi ntawm cov mortar.Thaum cov khoom ua kom zoo dua, cov dej tuav tus nqi ntawm cov mortar yog txhim kho.HPMC particle loj feem ntau siv rau cov cement mortar yuav tsum tsawg dua 180 microns (80 mesh screen).Qhov tsim nyog npaum li cas ntawm HPMC nyob rau hauv qhuav hmoov mortar yog 1‰～3‰.
2.1.Tom qab HPMC nyob rau hauv lub mortar yog yaj nyob rau hauv dej, kev ua tau zoo thiab kev faib ua feem ntawm cov cementitious cov ntaub ntawv nyob rau hauv lub system yog guaranteed vim lub nto ua hauj lwm.Raws li kev tiv thaiv colloid, HPMC " qhwv" cov khoom siv thiab tsim ib txheej ntawm nws sab nrauv.Ib txheej ntawm lubricating zaj duab xis ua rau cov mortar system ruaj khov, thiab tseem txhim kho cov kua dej ntawm cov mortar thaum lub sij hawm kev sib tov thiab kev ua kom zoo.
2.2.Vim nws cov qauv molecular, cov tshuaj HPMC ua rau cov dej hauv cov mortar tsis yooj yim poob, thiab tso tawm nws maj mam dhau lub sijhawm ntev, ua rau cov mortar nrog cov dej zoo thiab kev tsim kho.Nws tuaj yeem tiv thaiv cov dej ntws tawm sai dhau los ntawm mortar mus rau hauv paus, kom cov dej khaws cia nyob rau saum npoo ntawm cov khoom tshiab, uas tuaj yeem txhawb cov dej ntawm cov cement thiab txhim kho lub zog kawg.Tshwj xeeb tshaj yog yog hais tias lub interface nyob rau hauv kev sib cuag nrog cement mortar, plaster, thiab nplaum poob dej, qhov no yuav tsis muaj zog thiab yuav luag tsis muaj zog cohesive.Feem ntau hais lus, qhov chaw nyob rau hauv kev sib cuag nrog cov ntaub ntawv no yog tag nrho cov adsorbents, ntau dua los yog tsawg nqus ib co dej los ntawm qhov chaw, ua rau tsis tiav hydration ntawm qhov no, ua cement mortar thiab ceramic pobzeb substrates thiab ceramic vuas los yog plaster thiab phab ntsa Lub zog sib txuas ntawm. qhov chaw txo qis.
Hauv kev npaj ntawm mortar, kev tuav dej ntawm HPMC yog qhov ua tau zoo.Nws tau raug pov thawj tias cov dej tuav tau siab li 95%.Qhov nce ntawm qhov hnyav molecular ntawm HPMC thiab qhov nce ntawm cov cement yuav txhim kho cov dej tuav thiab kev sib raug zoo ntawm cov mortar.
Piv txwv li: Txij li cov pobzeb nplaum yuav tsum muaj lub zog siab ntawm ob qho tib si ntawm cov substrate thiab cov vuas, cov nplaum raug cuam tshuam los ntawm kev nqus dej los ntawm ob qhov chaw;lub substrate (phab ntsa) nto thiab cov vuas.Tshwj xeeb tshaj yog rau cov vuas, qhov zoo sib txawv heev, qee qhov muaj qhov pores loj, thiab cov vuas muaj cov dej nqus dej siab, uas ua rau kev ua haujlwm ntawm kev sib raug zoo.Tus neeg saib xyuas dej yog qhov tseem ceeb tshwj xeeb, thiab ntxiv HPMC tuaj yeem ua tau raws li qhov xav tau no.
2.3.HPMC yog ruaj khov rau cov kua qaub thiab alkali, thiab nws cov kua aqueous yog ruaj khov nyob rau hauv thaj tsam ntawm pH = 2 ~ 12.Caustic soda thiab txiv qaub dej tsis tshua muaj txiaj ntsig rau nws qhov kev ua tau zoo, tab sis alkali tuaj yeem ua kom nws tawg thiab ua kom nws viscosity me ntsis.
2.4.Kev tsim kho kev ua tau zoo ntawm cov mortar ntxiv nrog HPMC tau txhim kho tau zoo.Lub mortar zoo li yog "roj", uas tuaj yeem ua rau cov pob qij txha ntawm phab ntsa tag nrho, du nto, ua rau cov pobzeb lossis cib thiab cov txheej txheem txheej ruaj khov, thiab tuaj yeem ua kom lub sijhawm ua haujlwm ntev, haum rau thaj tsam loj.
2.5.HPMC yog ib qho uas tsis yog-ionic thiab tsis-polymeric electrolyte, uas yog ruaj khov heev nyob rau hauv aqueous daws nrog hlau ntsev thiab organic electrolytes, thiab yuav muab ntxiv rau lub tsev cov ntaub ntawv rau lub sij hawm ntev los xyuas kom meej nws durability yog zoo dua.
Post lub sij hawm: Jan-10-2023