Admixtures ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua haujlwm ntawm lub tsev qhuav-sib xyaw mortar.Cov nram qab no tshuaj xyuas thiab sib piv cov yam ntxwv ntawm cov latexr hmoov thiab cellulose, thiab tshuaj xyuas qhov kev ua tau zoo ntawm cov khoom siv tshuaj khib nyiab qhuav uas siv cov khoom sib xyaw.
Redispersible latex hmoov
Redispersible latexr hmoov yog ua tiav los ntawm kev ziab kom qhuav ntawm tshwj xeeb polymer emulsion.Cov hmoov latexr qhuav yog qee qhov sib txawv ntawm 80 ~ 100mm sib sau ua ke.Cov khoom no yog soluble nyob rau hauv dej thiab tsim ib tug ruaj khov dispersion me ntsis loj dua cov thawj emulsion hais, uas tsim ib zaj duab xis tom qab lub cev qhuav dej thiab qhuav.
Kev hloov pauv sib txawv ua rau cov hmoov av rov ua dua tshiab muaj cov khoom sib txawv xws li dej tsis kam, alkali tsis kam, huab cua tsis kam thiab yoog raws.latexr hmoov siv nyob rau hauv mortar tuaj yeem txhim kho qhov cuam tshuam, ua haujlwm ntev, hnav tsis kam, yooj yim ntawm kev tsim kho, kev sib txuas ntawm lub zog thiab cohesion, huab cua tsis kam, khov-thaw kuj, dej tiv thaiv, khoov lub zog thiab flexural zog ntawm cov tshuaj khib.
Cellulose ether
Cellulose ether yog cov ntsiab lus dav dav rau cov khoom lag luam uas tsim los ntawm cov tshuaj tiv thaiv ntawm alkali cellulose thiab etherifying tus neeg sawv cev nyob rau hauv qee yam mob.Alkali cellulose yog hloov los ntawm cov neeg ua haujlwm sib txawv kom tau txais cov cellulose ethers sib txawv.Raws li cov khoom ionization ntawm cov khoom hloov, cellulose ethers tuaj yeem muab faib ua ob pawg: ionic (xws li carboxymethyl cellulose) thiab non-ionic (xws li methyl cellulose).Raws li hom kev hloov pauv, cellulose ether tuaj yeem muab faib ua monoether (xws li methyl cellulose) thiab sib xyaw ether (xws li hydroxypropyl methyl cellulose).Raws li kev sib txawv solubility, nws tuaj yeem muab faib ua dej-soluble (xws li hydroxyethyl cellulose) thiab organic solvent-soluble (xws li ethyl cellulose), thiab lwm yam. Cov tshuaj khib nyiab qhuav yog dej-soluble cellulose, thiab dej-soluble cellulose yog muab faib ua hom instant thiab nto kho ncua sij hawm dissolution hom.
Lub mechanism ntawm kev txiav txim ntawm cellulose ether nyob rau hauv mortar yog raws li nram no:
(1) Tom qab cov cellulose ether nyob rau hauv lub mortar yog yaj nyob rau hauv dej, qhov zoo thiab niaj hnub faib ntawm cov cementitious khoom nyob rau hauv lub system yog guaranteed vim lub nto ua hauj lwm, thiab cov cellulose ether, raws li ib tug tiv thaiv colloid, "wraps" cov khoom. cov khoom thiab Ib txheej ntawm lubricating zaj duab xis yog tsim rau ntawm nws sab nrauv, uas ua rau cov mortar system ruaj khov, thiab tseem txhim kho cov kua dej ntawm cov mortar thaum lub sij hawm sib tov thiab smoothness ntawm kev tsim kho.
(2) Vim nws tus kheej cov qauv molecular, cov tshuaj cellulose ether ua rau cov dej hauv mortar tsis yooj yim ploj, thiab maj mam tso tawm rau lub sijhawm ntev, ua rau cov mortar nrog dej zoo thiab ua haujlwm tau zoo.
ntoo fiber
Ntoo fiber ntau yog tsim los ntawm cov nroj tsuag ua cov khoom siv tseem ceeb thiab ua tiav los ntawm cov thev naus laus zis, thiab nws qhov kev ua tau zoo sib txawv ntawm cov cellulose ether.Cov khoom tseem ceeb yog:
(1) Insoluble nyob rau hauv dej thiab cov kuab tshuaj, thiab kuj insoluble nyob rau hauv qaug zog acid thiab qaug zog hauv paus daws
(2) Siv rau hauv mortar, nws yuav sib tshooj rau hauv cov qauv peb sab hauv lub xeev zoo li qub, ua kom cov thixotropy thiab sag tsis kam ntawm mortar, thiab txhim kho kev tsim kho.
(3) Vim yog cov qauv peb-dimensional ntawm ntoo fiber ntau, nws muaj cov cuab yeej ntawm "dej-locking" nyob rau hauv cov mortar sib xyaw, thiab cov dej hauv mortar yuav tsis yooj yim absorbed los yog tshem tawm.Tab sis nws tsis muaj dej khaws cia ntawm cellulose ether.
(4) Cov nyhuv capillary zoo ntawm cov ntoo fiber ntau muaj kev ua haujlwm ntawm "dej conduction" nyob rau hauv mortar, uas ua rau saum npoo thiab sab hauv cov dej noo ntawm cov mortar zoo ib yam, yog li txo cov kab nrib pleb los ntawm qhov tsis sib xws.
(5) Ntoo fiber ntau tuaj yeem txo qhov deformation kev ntxhov siab ntawm cov mortar hardened thiab txo qhov shrinkage thiab cracking ntawm mortar.
Post lub sij hawm: Mar-10-2023