Hydroxypropyl Methyl Cellulose (HPMC)yog ib qho cellulose ether uas yaj tau hauv dej, uas siv dav hauv cov ntaub ntawv tsim kho, tshuaj pleev xim, tshuaj thiab zaub mov. Hauv cov ntaub ntawv tsim kho uas siv cement, HPMC, ua tus hloov kho, feem ntau ntxiv rau cov cement mortar kom txhim kho nws cov kev ua tau zoo, tshwj xeeb tshaj yog hauv cov txheej txheem ntawm kev tsim kho thiab kev siv. Nws muaj qhov cuam tshuam loj rau qhov fluidity, dej khaws cia, kev ua haujlwm thiab kev tiv thaiv tawg ntawm cov mortar.

 

1. Cov nyhuv ntawm HPMC rau qhov fluidity ntawm cement mortar
Qhov fluidity ntawm cement mortar yog ib qho cim qhia tseem ceeb los ntsuas nws cov kev ua tau zoo hauv kev tsim kho, uas cuam tshuam ncaj qha rau kev ua haujlwm zoo thiab zoo ntawm kev tsim kho. Ua ib yam khoom siv polymer, HPMC muaj cov dej solubility zoo thiab kev ua haujlwm ntawm qhov chaw. Tom qab ntxiv rau hauv cement mortar, nws tuaj yeem tsim ib zaj duab xis nyias los ntawm kev sib cuam tshuam ntawm cov molecular, ua rau cov viscosity ntawm cov mortar nce ntxiv, thiab yog li txhim kho qhov fluidity thiab kev ua haujlwm ntawm cov mortar. Tshwj xeeb, HPMC tuaj yeem kho qhov sib xws ntawm cov mortar, ua rau nws yooj yim dua rau kev thov thiab faib sib npaug thaum lub sijhawm tsim kho, zam kev nyuaj hauv kev tsim kho los ntawm kev ziab ntau dhau ntawm cov mortar.

HPMC kuj tseem tuaj yeem ntev lub sijhawm qhib ntawm cov tshuaj khib, uas yog, ua kom lub sijhawm siv ntawm cov tshuaj khib thaum lub sijhawm tsim kho, thiab zam kev cuam tshuam ntawm kev tsim kho uas cuam tshuam los ntawm kev ua dej sai dhau, tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab txias thiab qhuav.

 

2. Cov nyhuv ntawm HPMC rau kev khaws dej ntawm cov cement mortar
Qhov kev khaws dej ntawm cov cement mortar yog qhov tseem ceeb rau nws txoj kev tawv thiab kev loj hlob ntawm lub zog. Txij li thaum cov txheej txheem hydration cement xav tau dej txaus, yog tias cov dej poob ntawm cov mortar sai dhau thiab cov cement hydration tsis tiav, nws yuav cuam tshuam ncaj qha rau lub zog kawg thiab kev ruaj khov ntawm cov mortar. HPMC tuaj yeem txhim kho qhov kev khaws dej ntawm cov mortar. Cov hydroxypropyl thiab methyl pawg uas muaj nyob hauv nws cov qauv molecular muaj cov hydrophilicity muaj zog, uas tuaj yeem tsim cov txheej txheem khaws dej sib xws hauv cov mortar thiab txo qhov dej evaporation.

Tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab txias thiab qis av noo, qhov ntxiv ntawm HPMC tuaj yeem ncua qhov txheej txheem ziab ntawm cov cement mortar, xyuas kom meej tias cov cement muaj dej tag nrho, thiab yog li txhim kho qhov kawg lub zog thiab qhov tawg tsis kam ntawm mortar. Cov kev tshawb fawb tau qhia tias lub zog compressive thiab durability ntawm mortar nrog cov nqi tsim nyog ntawm HPMC ntxiv feem ntau zoo dua li cov tsis muaj HPMC hauv cov txheej txheem hardening mus sij hawm ntev.

 

3. Cov nyhuv ntawm HPMC rau qhov tawg tsis kam ntawm cov cement mortar
Cov kab nrib pleb yog ib qho teeb meem uas feem ntau cuam tshuam rau qhov zoo ntawm cov cement mortar, tshwj xeeb tshaj yog nyob rau hauv kev cuam tshuam ntawm cov yam xws li kev qhuav shrinkage, kev hloov pauv kub, thiab cov zog sab nraud, mortar yog qhov yooj yim tawg. Kev ntxiv HPMC tuaj yeem txhim kho qhov tsis kam ntawm mortar, feem ntau los ntawm cov hauv qab no:

Txhim kho qhov elasticity thiab plasticity ntawm cov mortar: HPMC muaj qee qhov elasticity thiab plasticity, uas tuaj yeem txo qhov kev ntxhov siab los ntawm kev ziab shrinkage thaum lub sijhawm kho cov mortar, yog li txo qhov tshwm sim ntawm cov kab nrib pleb.
Ua kom lub zog nplaum thiab lub zog tensile ntawm cov mortar nce ntxiv: HPMC tuaj yeem txhim kho lub zog nplaum thiab lub zog tensile ntawm cov mortar, tshwj xeeb tshaj yog thaum qhov chaw ntawm lub substrate tsis sib npaug lossis qhov adhesion ntawm lub substrate tsis zoo.
Tswj tus nqi ntawm cov cement hydration: Los ntawm kev tswj tus nqi ntawm cov cement hydration, HPMC tuaj yeem ncua qhov poob dej ntau dhau hauv cov cement mortar thiab txo qhov kev ntxhov siab ntsws los ntawm kev ua kom dej sai sai, yog li ntawd zoo tiv thaiv qhov tshwm sim ntawm cov kab nrib pleb.

 

4. Cov nyhuv ntawm HPMC rau lub zog thiab kev ua haujlwm ntev ntawm cov cement mortar
Txawm hais tias HPMC txhim kho qhov ua haujlwm tau zoo thiab tawg tsis kam ntawm cov cement mortar, nws kuj muaj qee qhov cuam tshuam rau nws lub zog thiab kev ua haujlwm ntev. Txawm hais tias ntxiv HPMC yuav txo qhov zog thaum ntxov ntawm cov mortar me ntsis vim tias nws cov qauv molecular siv ib feem ntawm cov dej uas xav tau rau kev ua kom cov cement noo, thaum kawg, HPMC pab ua kom cov cement noo tag nrho, yog li txhim kho qhov kawg ntawm cov mortar.

Tsis tas li ntawd xwb, HPMC tuaj yeem txhim kho qhov permeability ntawm cov cement mortar, txo qhov kev yaig ntawm cov mortar los ntawm dej lossis tshuaj lom neeg, thiab txhim kho nws lub zog. Qhov no ua rau cov mortar nrog HPMC ntxiv muaj kev ua tau zoo dua mus sij hawm ntev hauv qhov chaw ntub dej lossis corrosive, tshwj xeeb tshaj yog haum rau kev kho kom zoo nkauj phab ntsa sab nraud, kev paving pem teb thiab lwm yam teb.

 

5. Kev thov cov kev cia siab ntawm HPMC hauv cov ntaub ntawv siv cement
Nrog rau qhov kev thov nce ntxiv rau cov tshuaj mortar ua tau zoo hauv kev lag luam kev tsim kho, HPMC, ua ib qho khoom siv tseem ceeb, tau qhia txog kev siv dav hauv cov ntaub ntawv tsim kho uas siv cement. Ntxiv rau cov ntawv thov ib txwm muaj xws li kev pleev phab ntsa thiab cov tshuaj mortar hauv pem teb, HPMC kuj tseem siv tau rau hauv kev tsim cov tshuaj mortar uas ua rau nws tus kheej sib npaug, cov tshuaj mortar kho, cov tshuaj mortar sib xyaw qhuav thiab lwm yam khoom kom txhim kho kev ua tau zoo ntawm cov tshuaj mortar.

Nrog kev txhim kho ntawm cov kev cai rau kev tiv thaiv ib puag ncig thiab kev ruaj khov ntawm lub tsev, qhov tsis muaj kuab paug tsawg thiab VOC (volatile organic compound) cov yam ntxwv ntawm HPMC kuj ua rau nws muaj peev xwm zoo rau kev siv rau hauv cov ntaub ntawv tsim kho ntsuab. Tib lub sijhawm, nrog rau kev txhim kho tas mus li ntawm cov thev naus laus zis cuam tshuam, cov qauv hloov kho thiab daim ntawv thov ntawm HPMC yuav dhau los ua ntau yam, muab ntau txoj hauv kev rau kev tsim kho tshiab thiab kev txhim kho ntawm cov ntaub ntawv tsim kho cement.

 

Ua ib qho tseem ceeb ntawm cov cement mortar modifier, hydroxypropyl methylcellulose (HPMC) txhim kho kev ua haujlwm ntawm kev tsim kho thiab kev siv cov khoom siv cement los ntawm kev txhim kho qhov fluidity, dej tuav, tawg tsis kam thiab lub zog ntawm mortar. Nrog rau kev txhim kho tas mus li ntawm cov khoom siv hauv tsev, qhov kev siv HPMC yuav nthuav dav ntxiv, ua ib qho ntawm cov yam tseem ceeb hauv kev txhawb nqa kev txhim kho cov khoom siv hauv tsev niaj hnub.