Desulfurization gypsum yog cov roj flue uas tsim los ntawm kev sib xyaw ntawm cov sulfur-muaj roj (coal, roj av), cov khoom khib nyiab uas tsim tawm thaum lub sij hawm desulfurization purification txheej txheem, thiab cov hemihydrate gypsum (cov tshuaj formula CaSO4 · 0.5H2O), qhov kev ua tau zoo piv rau qhov ntawd. ntawm ntuj tsim gypsum. Yog li ntawd, muaj ntau thiab ntau kev tshawb fawb thiab kev siv ntawm kev siv desulfurized gypsum es tsis txhob ntawm ntuj gypsum los tsim cov ntaub ntawv tus kheej-leveling. Organic polymer admixtures xws li dej txo tus neeg saib xyuas, dej tuav tus neeg saib xyuas thiab retarder yog qhov tseem ceeb ua haujlwm hauv cov khoom siv ntawm tus kheej-leveling mortar. Kev sib cuam tshuam thiab cov txheej txheem ntawm ob nrog cov ntaub ntawv cementitious yog cov teeb meem tsim nyog rau kev saib xyuas ib qho. Vim yog cov yam ntxwv ntawm cov txheej txheem tsim, lub fineness ntawm desulfurized gypsum yog me me (qhov loj me yog feem ntau faib ntawm 40 thiab 60 μm), thiab cov hmoov gradation yog tsis tsim nyog, yog li cov rheological zog ntawm desulfurized gypsum yog cov neeg pluag, thiab mortar. slurry npaj los ntawm nws yog feem ntau yooj yim Segregation, stratification thiab los ntshav tshwm sim. Cellulose ether yog feem ntau siv admixture nyob rau hauv mortar, thiab nws ua ke siv nrog dej txo tus neeg sawv cev yog ib qho tseem ceeb guarantee kom paub qhov kev ua tau zoo ntawm desulfurized gypsum-raws li tus kheej-leveling cov ntaub ntawv xws li kev tsim kho thiab tom qab txhua yam thiab durability kev ua tau zoo.
Nyob rau hauv daim ntawv no, tus nqi fluidity yog siv raws li kev tswj Performance index (kis degree 145 mm ± 5 mm), tsom rau qhov cuam tshuam ntawm cov ntsiab lus ntawm cellulose ether thiab molecular hnyav (viscosity tus nqi) ntawm cov dej noj ntawm desulfurized gypsum raws li tus kheej. -leveling cov ntaub ntawv, qhov poob ntawm fluidity nyob rau lub sij hawm, thiab cov coagulation Txoj cai ntawm kev cuam tshuam ntawm lub hauv paus zog xws li lub sij hawm thiab thaum ntxov mechanical zog; Nyob rau tib lub sijhawm, sim txoj cai ntawm kev cuam tshuam ntawm cellulose ether ntawm lub tshav kub tso tawm thiab tso cua sov tus nqi ntawm desulfurized gypsum hydration, txheeb xyuas nws cov cawv ntawm cov txheej txheem hydration ntawm desulfurized gypsum, thiab pib tham txog hom admixture Compatibility nrog desulfurization gypsum gelling system. .
1. Cov ntaub ntawv raw thiab cov txheej txheem xeem
1.1 Cov khoom siv raw
Gypsum hmoov: desulfurized gypsum hmoov tsim los ntawm ib lub tuam txhab nyob rau hauv Tangshan, lub ntsiab ntxhia muaj pes tsawg leeg yog hemihydrate gypsum, nws cov tshuaj muaj pes tsawg leeg yog qhia nyob rau hauv Table 1, thiab nws lub cev muaj zog muaj nyob rau hauv daim duab 2.
duab
duab
Admixtures muaj xws li: cellulose ether (hydroxypropyl methylcellulose, HPMC luv luv); superplasticizer WR; defoamer B-1; EVA redispersible latex hmoov S-05, tag nrho cov khoom lag luam muaj.
Aggregate: ntuj dej xuab zeb, nws tus kheej ua zoo xuab zeb sieved los ntawm ib tug 0.6 hli sieve.
1.2 Test method
Tsau desulfurization gypsum: xuab zeb: dej = 1: 0.5: 0.45, tus nqi tsim nyog ntawm lwm cov khoom sib xyaw, fluidity raws li qhov ntsuas ntsuas (ntev 145 hli ± 5 hli), los ntawm kev kho cov dej noj, feem sib xyaw nrog cov khoom siv cementitious (desulfurization gypsum + Cement. ) 0, 0.5‰, 1.0‰, 2.0‰, 3.0‰ cellulose ether (HPMC-20,000); txuas ntxiv kho cov koob tshuaj ntawm cellulose ether rau 1‰, xaiv HPMC-20,000, HPMC-40,000, HPMC-75,000, thiab HPMC-100,000 hydroxypropyl methylcellulose ethers nrog qhov sib txawv ntawm qhov hnyav (cov lej sib xws yog H2, H4, thiab H2. ), los kawm txog qhov ntau npaum li cas thiab qhov hnyav molecular (tus nqi viscosity) ntawm cellulose ether Qhov cuam tshuam ntawm cov kev hloov pauv ntawm cov khoom ntawm gypsum-based self-leveling mortar, thiab kev cuam tshuam ntawm ob qho tib si ntawm fluidity, teeb tsa lub sijhawm thiab cov khoom siv thaum ntxov ntawm cov desulfurized gypsum nws tus kheej-leveling mortar sib tov yog tham. Txoj kev ntsuas tshwj xeeb yog ua raws li qhov yuav tsum tau ua ntawm GB / T 17669.3-1999 "Kev txiav txim siab ntawm Cov Khoom Siv Hluav Taws Xob ntawm Lub Tsev Gypsum".
Kev ntsuas kub ntawm hydration yog ua los ntawm kev siv ib qho qauv dawb ntawm desulfurized gypsum thiab cov qauv nrog cellulose ether cov ntsiab lus ntawm 0.5‰ thiab 3‰, raws li, thiab cov cuab yeej siv yog TA-AIR hom cua sov ntawm hydration tester.
2. Cov txiaj ntsig thiab kev tshuaj xyuas
2.1 Cov txiaj ntsig ntawm cellulose ether cov ntsiab lus ntawm cov khoom tseem ceeb ntawm mortar
Nrog rau qhov nce ntawm cov ntsiab lus, kev ua haujlwm thiab kev sib koom ua ke ntawm cov tshuaj khib nyiab tau txhim kho zoo, qhov poob ntawm cov dej hauv lub sijhawm raug txo qis, thiab kev tsim kho kev ua tau zoo dua qub, thiab cov mortar hardened tsis muaj qhov tshwm sim delamination, thiab qhov smoothness, smoothness thiab Aesthetics tau zoo heev. Nyob rau tib lub sijhawm, kev siv dej ntawm cov tshuaj khib kom ua tiav tib lub fluidity tau nce ntau. Ntawm 5‰, cov dej haus tau nce 102%, thiab lub sijhawm teem sijhawm kawg tau ncua ntev li 100 min, uas yog 2.5 npaug ntawm cov qauv dawb. Cov khoom siv thaum ntxov ntawm mortar txo qis nrog qhov nce ntawm cov ntsiab lus ntawm cellulose ether. Thaum cov ntsiab lus ntawm cellulose ether yog 5‰, 24 h flexural zog thiab compressive zog poob mus rau 18.75% thiab 11.29% ntawm cov qauv dawb paug raws li. Lub zog compressive yog 39.47% thiab 23.45% ntawm cov qauv dawb paug feem. Nws yog ib qho tsim nyog sau cia tias nrog kev nce ntawm cov dej khaws cia, qhov ntom ntom ntawm cov mortar kuj txo qis, los ntawm 2069 kg / m3 ntawm 0 txog 1747 kg / m3 ntawm 5‰, txo qis ntawm 15.56%. Qhov ntom ntawm cov mortar txo qis thiab qhov porosity nce, uas yog ib qho ntawm cov laj thawj rau qhov pom tseeb txo qis hauv cov khoom ntawm cov tshuaj khib nyiab.
Cellulose ether yog non-ionic polymer. Cov pawg hydroxyl ntawm cov cellulose ether saw thiab cov pa atoms ntawm ether daim ntawv cog lus tuaj yeem ua ke nrog cov dej molecules los tsim hydrogen bonds, tig dej dawb rau hauv cov dej khi, yog li ua lub luag haujlwm hauv dej tuav. Macroscopically Nws yog manifested raws li ib tug nce nyob rau hauv lub cohesiveness ntawm slurry [5]. Kev nce hauv slurry viscosity yuav tsis tsuas yog nce cov dej noj, tab sis kuj yog cov yaj cellulose ether yuav adsorbed rau saum npoo ntawm gypsum hais, cuam tshuam cov tshuaj tiv thaiv hydration thiab ncua sij hawm teem caij; Thaum lub sij hawm stirring, ib tug loj tus naj npawb ntawm huab cua npuas kuj yuav qhia. Voids yuav tsim raws li lub mortar hardens, nws thiaj li txo lub zog ntawm lub mortar. Kev txiav txim siab txog kev siv dej tsis sib haum ntawm cov tshuaj khib nyiab sib xyaw, kev tsim kho kev ua haujlwm, teeb tsa lub sijhawm thiab cov khoom siv kho tshuab, thiab tom qab ua haujlwm ntev, thiab lwm yam, cov ntsiab lus ntawm cellulose ether hauv desulfurized gypsum-based self-leveling mortar yuav tsum tsis pub tshaj 1‰.
2.2 Cov nyhuv ntawm molecular hnyav ntawm cellulose ether ntawm kev ua haujlwm ntawm mortar
Feem ntau, qhov siab dua qhov viscosity thiab qhov zoo ntawm cellulose ether, qhov zoo dua cov dej tuav thiab ua kom lub zog sib txuas. kev ua haujlwm yuav raug cuam tshuam tsis zoo. Yog li ntawd, kev cuam tshuam ntawm cellulose ethers ntawm qhov sib txawv molecular hnyav ntawm cov khoom ntawm gypsum-based self-leveling mortar cov ntaub ntawv tau sim ntxiv. Cov dej xav tau ntawm cov mortar tau nce mus rau qee qhov, tab sis tsis muaj qhov cuam tshuam rau lub sijhawm teeb tsa thiab dej ntws. Nyob rau tib lub sijhawm, flexural thiab compressive zog ntawm mortar nyob rau hauv ntau lub xeev tau pom ib qho kev poob qis, tab sis qhov poob qis dua qhov cuam tshuam ntawm cellulose ether cov ntsiab lus ntawm cov khoom siv kho tshuab. Hauv cov ntsiab lus, qhov nce ntawm qhov hnyav molecular ntawm cellulose ether tsis muaj kev cuam tshuam rau kev ua haujlwm ntawm cov tshuaj khib nyiab. Xav txog qhov yooj yim ntawm kev tsim kho, tsawg-viscosity thiab me-molecular-yuag cellulose ether yuav tsum tau xaiv raws li desulfurized gypsum-based self-leveling cov ntaub ntawv.
2.3 Cov nyhuv ntawm cellulose ether ntawm tshav kub ntawm hydration ntawm desulfurized gypsum
Nrog rau qhov nce ntawm cov ntsiab lus ntawm cellulose ether, exothermic ncov ntawm hydration ntawm desulfurized gypsum maj mam txo, thiab lub sij hawm ntawm lub ncov txoj hauj lwm tau qeeb me ntsis, thaum lub exothermic tshav kub ntawm hydration txo, tab sis tsis pom tseeb. Qhov no qhia tau hais tias cellulose ether tuaj yeem ncua lub hydration tus nqi thiab hydration degree ntawm desulfurized gypsum rau ib qho twg, yog li qhov ntau npaum li cas yuav tsum tsis txhob loj dhau, thiab yuav tsum tau tswj tsis pub dhau 1‰. Nws tuaj yeem pom tias cov yeeb yaj kiab colloidal tsim tom qab cellulose ether ntsib dej yog adsorbed rau saum npoo ntawm desulfurized gypsum hais, uas txo cov dej ntawm gypsum ua ntej 2 teev. Nyob rau tib lub sijhawm, nws cov dej tshwj xeeb khaws cia thiab thickening cuam tshuam ncua lub evaporation ntawm slurry dej thiab Dissipation yog qhov zoo rau cov dej ntxiv ntawm desulfurized gypsum nyob rau theem tom ntej. Piv txwv li, thaum tswj cov koob tshuaj uas tsim nyog, cellulose ether tau txwv tsis pub muaj kev cuam tshuam ntawm hydration tus nqi thiab hydration degree ntawm desulfurized gypsum nws tus kheej. Nyob rau tib lub sijhawm, qhov nce ntawm cellulose ether cov ntsiab lus thiab qhov hnyav ntawm molecular yuav ua rau kom cov viscosity ntawm slurry thiab qhia cov dej tuav tau zoo heev. Txhawm rau kom ntseeg tau tias qhov fluidity ntawm desulfurized gypsum self-leveling mortar, cov dej haus yuav nce ntxiv, uas yog vim lub sijhawm ntev ntawm cov tshuaj khib nyiab. Lub ntsiab yog vim li cas rau qhov poob ntawm mechanical zog.
3. Cov lus xaus
(1) Thaum fluidity yog siv raws li kev tswj Performance index, nrog rau kev nce ntawm cellulose ether cov ntsiab lus, lub sij hawm teem ntawm desulfurized gypsum-raws li tus kheej-leveling mortar yog ho ntev, thiab cov neeg kho tshuab zog yog ho txo; piv nrog rau cov ntsiab lus, qhov hnyav molecular ntawm cellulose ether Qhov nce tau me ntsis cuam tshuam rau cov khoom saum toj no ntawm mortar. Kev txiav txim siab zoo, cellulose ether yuav tsum tau xaiv nrog qhov hnyav me me (tus nqi viscosity qis dua 20 000 Pa·s), thiab cov tshuaj yuav tsum tau tswj tsis pub dhau 1‰ ntawm cov khoom siv cementitious.
(2) Cov txiaj ntsig ntawm kev ntsuas dej kub ntawm desulfurized gypsum qhia tau hais tias nyob rau hauv qhov kev sim ntawm qhov kev sim no, cellulose ether tau txwv tsis pub muaj kev cuam tshuam ntawm cov dej thiab cov txheej txheem hydration ntawm desulfurized gypsum. Kev siv dej ntau ntxiv thiab qhov txo qis hauv qhov ntau yog qhov laj thawj tseem ceeb rau kev txo qis hauv cov khoom siv ntawm desulfurized gypsum-based mortar.
Post lub sij hawm: May-08-2023