HPMC (Hydroxypropyl Methylcellulose)yog cov khoom siv tshuaj polymer feem ntau siv hauv kev tsim kho kev lag luam. Nws yog dav siv hauv cov cement-based mortar, qhuav-siv mortar, adhesives thiab lwm yam khoom kom tuab, khaws dej, txhim kho Nws muaj ntau yam haujlwm xws li adhesion thiab txhim kho kev tsim kho. Nws lub luag haujlwm hauv mortar yog qhov tseem ceeb, tshwj xeeb tshaj yog nyob rau hauv kev txhim kho qhov tawg tsis kam ntawm mortar.
1. Txhim khu kev tuav dej
HPMC muaj cov dej tuav tau zoo, uas txhais tau hais tias cov dej yuav tsis evaporate sai heev thaum lub sij hawm siv tshuaj khib, yog li tsis txhob shrinkage tawg los ntawm dej ntau dhau. Tshwj xeeb tshaj yog nyob rau hauv qhuav thiab kub-kub ib puag ncig, dej tuav nyhuv ntawm HPMC yog tshwj xeeb tshaj yog zoo. Cov dej noo hauv cov mortar tuaj yeem nyob ruaj khov rau qee lub sijhawm kom tsis txhob ziab ntxov ntxov, uas yog qhov tseem ceeb heev rau kev txhim kho qhov tawg ntawm cov tshuaj khib nyiab. Kev tuav dej tuaj yeem ncua cov txheej txheem hydration ntawm cov cement, tso cai rau cov cement hais kom tag nrho cov dej nyob rau lub sij hawm ntev, yog li txhim kho qhov tawg ntawm cov mortar.
2. Txhim kho qhov adhesion ntawm mortar
Raws li cov thickener, HPMC tuaj yeem tsim cov qauv zoo molecular network hauv mortar txhawm rau txhim kho qhov adhesion thiab fluidity ntawm mortar. Qhov no tsis tsuas yog txhim kho lub zog sib txuas ntawm cov tshuaj khib thiab lub hauv paus txheej thiab txo qhov tawg ntawm txheej txheej, tab sis kuj txhim kho tag nrho cov tawv nqaij ntawm cov mortar thiab txo qhov tshwm sim ntawm cov kab nrib pleb tshwm sim los ntawm sab nraud quab yuam thaum lub sij hawm tsim kho. Zoo adhesion ua rau cov mortar ntau yam thaum lub sij hawm tsim kho thiab txo cov kab nrib pleb tshwm sim los ntawm qhov tsis sib xws ntawm cov pob qij txha.
3. Txhim kho cov yas thiab kev ua haujlwm ntawm mortar
HPMC txhim kho cov yas thiab kev ua haujlwm ntawm mortar, uas tuaj yeem txhim kho qhov yooj yim ntawm kev tsim kho. Vim nws cov nyhuv thickening, HPMC tuaj yeem ua rau cov mortar zoo dua adhesion thiab formability, zoo txo qhov tshwm sim ntawm cov kab nrib pleb tshwm sim los ntawm cov mortar tsis sib xws thiab tsis muaj fluidity thaum lub sij hawm tsim kho. Plasticity zoo ua rau cov mortar ntau sib npaug thaum lub sij hawm ziab thiab shrinkage, txo qhov muaj peev xwm ntawm cov kab nrib pleb vim tsis sib xws.
4. Txo qhov shrinkage tawg
Dry shrinkage yog lub ntim ntim uas tshwm sim los ntawm cov dej evaporation thaum lub sij hawm ziab ntawm mortar. Ntau dhau qhuav shrinkage yuav ua rau tawg ntawm qhov chaw los yog sab hauv ntawm lub mortar. HPMC ua kom cov dej ntws tawm sai sai thiab txo qhov tshwm sim ntawm qhov qhuav qhuav los ntawm nws cov dej khaws cia siab thiab txhim kho plasticity. Kev tshawb fawb qhia tau hais tias mortar ntxiv nrog HPMC muaj qhov qis qis qis qis thiab nws cov ntim hloov pauv tsawg dua thaum lub sijhawm ziab, yog li tiv thaiv cov kab nrib pleb los ntawm kev ziab kom qhuav. Rau cov phab ntsa loj lossis cov plag tsev, tshwj xeeb tshaj yog nyob rau lub caij ntuj sov lossis qhov cua thiab qhov chaw qhuav, lub luag haujlwm ntawm HPMC yog qhov tseem ceeb tshwj xeeb.
5. Txhim kho qhov tawg tsis kam ntawm mortar
Cov qauv molecular ntawm HPMC tuaj yeem tsim qee yam tshuaj lom neeg sib cuam tshuam nrog cov cement thiab lwm yam khoom siv tsis zoo hauv mortar, ua rau cov mortar muaj zog dua tom qab hardening. Qhov no txhim khu kev tawg lub zog tsis yog tsuas yog los ntawm kev sib xyaw nrog HPMC thaum lub sij hawm cement hydration txheej txheem, tab sis kuj txhim kho lub toughness ntawm mortar rau ib yam twg. Lub toughness ntawm lub mortar tom qab hardening yog txhim khu kev qha, uas pab nws tiv taus loj sab nraud kev nyuaj siab thiab yog tsis yooj yim rau tawg. Tshwj xeeb tshaj yog nyob rau hauv ib puag ncig uas muaj qhov sib txawv ntawm qhov kub thiab txias lossis kev hloov pauv loj hauv cov khoom siv sab nraud, HPMC tuaj yeem txhim kho qhov tawg ntawm cov mortar.
6. Ua kom cov impermeability ntawm mortar
Raws li cov khoom siv organic polymer, HPMC tuaj yeem tsim cov qauv siv hluav taws xob microscopic hauv mortar los txhim kho qhov kev cog lus ntawm cov mortar. Cov yam ntxwv no ua rau cov mortar ntau impermeable thiab txo cov permeability ntawm ya raws thiab lwm yam xov xwm sab nraud. Nyob rau hauv ib qho chaw ntub dej los yog dej-soaked, cov kab nrib pleb ntawm qhov chaw thiab sab hauv ntawm cov mortar feem ntau yuav cuam tshuam los ntawm cov dej noo, ua rau muaj kev nthuav dav ntxiv ntawm cov kab nrib pleb. Qhov sib ntxiv ntawm HPMC tuaj yeem txo qhov nkag mus ntawm cov dej thiab inhibit qhov kev nthuav dav ntawm cov kab nrib pleb los ntawm cov dej nkag, yog li txhim kho qhov tawg ntawm cov tshuaj khib rau qee yam.
7. inhibit kev tsim thiab nthuav ntawm micro-cracks
Thaum lub sij hawm ziab thiab hardening txheej txheem ntawm mortar, micro tawg feem ntau tshwm sim nyob rau hauv, thiab cov kab nrib pleb no yuav maj mam nthuav thiab tsim cov kab nrib pleb nyob rau hauv qhov kev txiav txim ntawm sab nraud rog. HPMC tuaj yeem tsim cov qauv sib xws hauv lub mortar los ntawm nws cov qauv molecular, txo qhov tshwm sim ntawm micro-cracks. Txawm hais tias micro-cracks tshwm sim, HPMC tuaj yeem ua lub luag haujlwm tiv thaiv kev tawg thiab tiv thaiv lawv los ntawm kev nthuav dav ntxiv. Qhov no yog vim hais tias cov saw hlau polymer ntawm HPMC tuaj yeem cuam tshuam qhov kev ntxhov siab ntawm ob sab ntawm qhov tawg los ntawm kev sib cuam tshuam hauv cov tshuaj khib nyiab, yog li inhibiting qhov kev nthuav dav ntawm qhov tawg.
8. Txhim kho qhov elastic modulus ntawm mortar
Elastic modulus yog qhov taw qhia tseem ceeb ntawm cov khoom muaj peev xwm tiv thaiv deformation. Rau mortar, lub siab elastic modulus tuaj yeem ua rau nws ruaj khov dua thaum raug rau sab nraud quab yuam thiab tsis tshua muaj peev xwm ua rau ntau dhau deformation lossis tawg. Raws li cov yas yas, HPMC tuaj yeem ua rau nws cov elastic modulus nyob rau hauv mortar, tso cai rau lub mortar kom nws zoo dua nyob rau hauv qhov kev txiav txim ntawm sab nraud rog, yog li txo qhov tshwm sim ntawm cov kab nrib pleb.
HPMCUa tau zoo txhim kho qhov tawg tsis kam ntawm mortar nyob rau hauv ntau yam los ntawm kev txhim kho cov dej tuav, adhesion, plasticity thiab operability ntawm mortar, txo qhov tshwm sim ntawm qhuav shrinkage kab nrib pleb, thiab kev txhim kho cov tawg tiv thaiv lub zog, impermeability thiab elastic modulus. kev ua tau zoo. Yog li ntawd, daim ntawv thov ntawm HPMC nyob rau hauv kev tsim kho mortar tsis tsuas yog txhim kho qhov tawg tsis kam ntawm cov mortar, tab sis kuj txhim kho kev tsim kho kev ua tau zoo thiab txuas ntxiv lub neej kev pab cuam ntawm mortar.
Post lub sij hawm: Dec-16-2024