Cellulose Ether Viscosity Canjin Canjin Siminti akan filasta

Kauri shine muhimmin tasirin gyare-gyare na ether cellulose akan kayan tushen ciminti. Tasirin abun ciki na ether cellulose, saurin jujjuyawar viscometer da zafin jiki akan canjin danko na siminti ether da aka gyara.tushen plaster aka yi nazari. Sakamakon ya nuna cewa danko na simintitushen plaster yana ƙaruwa ci gaba tare da haɓaka abun ciki na ether cellulose, da danko na ether na cellulose da siminti.tushen plaster yana da "sakamako mai hadewa"; da pseudoplasticity na cellulose ether gyara simintitushen plaster ya yi ƙasa da na siminti zallatushen plaster, da danko Ƙananan saurin juyawa na kayan aiki, ko ƙananan danko na cellulose ether gyare-gyaren simintitushen plaster, ko ƙananan abun ciki na ether cellulose, mafi mahimmancin pseudoplasticity na cellulose ether gyare-gyaren ciminti.tushen plaster; Tare da hadewar sakamako na hydration, danko na ether cellulose ya canza simintitushen plaster zai karu ko raguwa. Daban-daban na ether cellulose suna da canje-canje daban-daban a cikin danko na ciminti da aka gyaratushen plaster.

Mabuɗin kalmomi: ether cellulose; simintitushen plaster; danko

0,Gabatarwa

Ana amfani da ethers na cellulose sau da yawa azaman masu riƙe ruwa da masu kauri don kayan tushen siminti. A cewar daban-daban substituents, cellulose ethers amfani da sumunti-tushen kayan kullum sun hada da methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxyethyl methyl cellulose Ether (Hydroxyethyl methyl cellulose, HEMC) da hydroxypropyl methyl cellulose (Hydroxypropyl methyl), cellulose, HPMC. daga cikinsu HPMC da HEMC ne aka fi amfani da su.

Kauri shine muhimmin tasirin gyare-gyare na ether cellulose akan kayan tushen ciminti. Cellulose ether na iya ba da rigar turmi tare da ingantacciyar danko, yana haɓaka ikon haɗin kai tsakanin jikar turmi da tushe mai tushe, da haɓaka aikin anti-sag na turmi. Hakanan yana iya ƙara haɓaka kamanni da ƙarfin tarwatsewar sabbin kayan da aka haɗa da siminti, da kuma hana lalata, rarrabuwa da zubar da jini na turmi da kankare.

Tasirin kauri na ether cellulose akan kayan tushen siminti za'a iya ƙididdige ƙididdigewa ta hanyar ƙirar rheological na kayan tushen siminti. Abubuwan da ke tushen siminti galibi ana ɗaukarsu azaman ruwan Bingham, wato, lokacin da ƙarfin juzu'i na r ya yi ƙasa da yawan damuwa r0, kayan ya kasance a cikin ainihin siffarsa kuma baya gudana; lokacin da danniya mai shear r ya zarce yawan abin da ake samu r0, abu yana fuskantar nakasu mai gudana, da damuwa mai shear.·y, inda f shine dankowar filastik. Cellulose ethers gabaɗaya yana ƙara yawan ƙarfin amfanin ƙasa da dankon filastik na kayan tushen siminti, duk da haka, ƙananan allurai suna haifar da ƙarancin ƙarancin amfanin gona da dankon filastik, galibi saboda tasirin iska na ethers cellulose. Binciken Patural ya nuna cewa nauyin kwayoyin halitta na cellulose ether yana ƙaruwa, yawan yawan damuwa na simintitushen plaster yana raguwa, kuma daidaito yana ƙaruwa.

Dankowar simintitushen plaster wani muhimmin ma'auni ne don kimanta tasirin kauri na ether cellulose akan kayan tushen ciminti. Wasu wallafe-wallafen sun binciko ka'idar canjin danko na maganin cellulose ether, amma har yanzu akwai rashin bincike mai dacewa game da tasirin cellulose ether akan canjin danko na ciminti.tushen plaster. A lokaci guda, bisa ga nau'ikan nau'ikan maye gurbin, akwai nau'ikan ethers na cellulose da yawa. Tasirin nau'o'in nau'i daban-daban da danko na ethers cellulose akan canjin simintitushen plaster Danko kuma lamari ne mai matukar damuwa a cikin amfani da ethers cellulose. Wannan aikin yana amfani da viscometer na jujjuya don nazarin canje-canjen danko na cellulose ether gyare-gyaren ciminti slurries iri daban-daban da viscosities a ƙarƙashin ma'auni daban-daban na poly-ash, saurin juyawa da yanayin zafi.

1. Gwaji

1.1 Kayan danye

(1) Cellulose ether. An zabo nau'ikan ethers guda shida na cellulose da aka fi amfani da su a ƙasata, waɗanda suka haɗa da nau'in MC guda ɗaya, nau'in HEC guda 1, HPMC iri biyu da HEMC iri biyu, daga cikinsu akwai ɗanɗano nau'in HPMC guda biyu da na HEMC iri biyu. daban. An gwada danko na cellulose ether ta NDJ-1B viscometer juyawa (Kamfanin Shanghai Changji), ƙaddamar da maganin gwajin shine 1.0% ko 2.0%, zafin jiki shine 20.°C, kuma saurin juyawa ya kasance 12r/min.

(2) Siminti. Simintin Portland na yau da kullun wanda Wuhan Huaxin Cement Co., Ltd ya kera yana da takamaiman P·O 42.5 (GB 175-2007).

1.2 Hanyar auna ma'aunin danko na maganin ether cellulose

Ɗauki samfurin ether cellulose na ƙayyadaddun ingancin kuma ƙara shi zuwa gilashin gilashin 250mL, sannan ƙara 250g na ruwan zafi a kusan 90.°C; motsawa sosai tare da sandar gilashi don sanya ether cellulose ya zama tsarin watsawa iri ɗaya a cikin ruwan zafi, kuma a lokaci guda sanya beaker Cool a cikin iska. Lokacin da maganin ya fara haifar da danko kuma ba zai sake yin hazo ba, dakatar da motsawa nan da nan; lokacin da aka kwantar da maganin a cikin iska har sai launin ya zama iri ɗaya, sanya beaker a cikin ruwan wanka mai zafi akai-akai, kuma kiyaye zafin jiki zuwa yanayin da aka ƙayyade. Kuskuren shine± 0.1°C; bayan 2h (ƙididdigewa daga lokacin hulɗar ether cellulose tare da ruwan zafi), auna zafin jiki na tsakiyar bayani tare da ma'aunin zafi da sanyio. Production) an saka rotor a cikin bayani zuwa zurfin ƙayyadadden, bayan tsayawa na 5min, auna danko.

1.3 Ma'aunin danko na simintin ether da aka gyaratushen plaster

Kafin gwajin, ajiye duk albarkatun da aka ƙayyade a zafin jiki da aka ƙayyade, auna adadin adadin ether cellulose da siminti, haɗa su sosai, kuma ƙara ruwan famfo a cikin zafin jiki da aka ƙayyade a cikin gilashin gilashin 250mL tare da rabon ruwa-ciminti na 0.65; sai ki zuba busasshen foda a cikin busasshiyar ki dakata na tsawon mintuna 3, ki zuga sosai da sandar gilashi har sau 300, a saka rotor na viscometer mai juyi (nau'in NDJ-1B, wanda Shanghai Changji Geological Instrument Co., Ltd. ya samar) a cikin bayani zuwa ƙayyadadden zurfin, kuma auna danko bayan tsayawa na minti 2. Don kauce wa tasirin zafi na ciminti hydration zafi akan gwajin danko na simintitushen plaster kamar yadda zai yiwu, da danko na cellulose ether modified cimintitushen plaster dole ne a gwada lokacin da siminti ya kasance cikin hulɗa da ruwa na minti 5.

2. Sakamako da bincike

2.1 Tasirin abun ciki na ether cellulose

Adadin ether cellulose a nan yana nufin yawan adadin ether cellulose zuwa siminti, wato, rabon polyash. Daga tasirin P2, E2 da H1 iri uku na ethers cellulose akan canjin danko na ciminti.tushen plaster a daban-daban dosages (0.1%, 0.3%, 0.6% da 0.9%), ana iya ganin cewa bayan ƙara cellulose ether, danko na ciminti.tushen plaster Danko yana ƙaruwa; yayin da adadin ether cellulose ya karu, danko na cimintitushen plaster yana ƙaruwa akai-akai, da kewayon karuwa a cikin danko na simintitushen plaster kuma ya zama ya fi girma.

Lokacin da rabon ruwa-ciminti shine 0.65 kuma abun ciki na ether cellulose shine 0.6%, la'akari da ruwan da aka cinye ta farkon hydration na ciminti, ƙaddamar da ether cellulose dangane da ruwa shine kusan 1%. Lokacin da maida hankali ya kasance 1%, P2, E2 da H1 mafita mai ruwa.·S, 5070mPa·S da 5250mPa·s bi da bi; lokacin da rabon ruwa-ciminti shine 0.65, danko na siminti mai tsabtatushen plaster da 836mPa·S. Duk da haka, danko na P2, E2 da H1 uku cellulose ether modified ciminti slurries ne 13800mPa·S, 12900mPa·S da 12700mPa·s bi da bi. Babu shakka, danko na cellulose ether ciminti gyaratushen plaster ba shine danko na cellulose ether bayani ba kuma Ƙari mai sauƙi na danko na ciminti mai tsabtatushen plaster yana da mahimmanci fiye da jimlar viscosities biyu, wato, danko na ether na cellulose da kuma danko na siminti.tushen plaster suna da “composite superposition effect”. Danko na cellulose ether bayani ya fito ne daga karfi hydrophilicity na hydroxyl kungiyoyin da ether bond a cikin cellulose ether kwayoyin halitta da uku-girma cibiyar sadarwa tsarin kafa ta cellulose ether kwayoyin a cikin bayani; Dankowar siminti zallatushen plaster ya fito ne daga hanyar sadarwar da aka kafa tsakanin tsarin samfuran hydration na siminti. Tun da polymer da ciminti hydration kayayyakin sau da yawa samar da interpenetrating cibiyar sadarwa tsarin, a cikin cellulose ether modified ciminti.tushen plaster, tsarin cibiyar sadarwa mai girma uku na cellulose ether da tsarin cibiyar sadarwa na samfurori na siminti hydration suna haɗuwa, da kuma cellulose ether kwayoyin Adsorption tare da siminti hydration kayayyakin tare samar da wani "composite superposition sakamako", wanda muhimmanci qara da overall danko na siminti.tushen plaster; tun da kwayar halitta cellulose ether guda ɗaya na iya yin hulɗa tare da ƙwayoyin ether na cellulose da yawa da samfuran hydration na siminti, Saboda haka, tare da haɓaka abun ciki na ether cellulose, yawan tsarin cibiyar sadarwa yana ƙaruwa fiye da haɓakar ƙwayoyin ether cellulose, da danko na siminti.tushen plaster yana ƙaruwa ci gaba; Bugu da ƙari, saurin hydration na siminti yana buƙatar amsa wani ɓangare na ruwa. , wanda yayi daidai da ƙara yawan ƙwayar cellulose ether, wanda kuma shine dalili na karuwa mai yawa a cikin danko na siminti.tushen plaster.

Tun da cellulose ether da cimintitushen plaster suna da "tasiri mai haɗaɗɗun superposition" a cikin danko, a ƙarƙashin wannan abun ciki na ether cellulose da yanayin rabo na ruwa-ciminti, danko na cellulose ether modified ciminti.tushen plaster tare da bayyane bambanci lokacin da maida hankali ne 2% Bambancin danko ba babba bane, alal misali, danko na P2 da E2 sune 48000mPa·s da 36700mPa·s bi da bi a cikin maganin ruwa tare da maida hankali na 2%. S, bambancin ba a fili yake ba; Danko na E1 da E2 a cikin 2% maganin ruwa shine 12300mPa·S da 36700mPa·s bi da bi, bambancin yana da girma sosai, amma danko na ciminti da aka gyara shine 9800mPa·S da 12900mPa bi da bi·S, an rage bambanci sosai, don haka lokacin zabar ether cellulose a aikin injiniya, ba lallai ba ne a bi diddigin girman ether na cellulose. Bugu da ƙari, a aikace-aikacen injiniya mai amfani, ƙaddamar da ether cellulose dangane da ruwa yawanci yana da ƙananan ƙananan. Misali, a cikin turmi plastering na yau da kullun, rabon siminti na ruwa yawanci kusan 0.65 ne, kuma abun ciki na ether cellulose shine 0.2% zuwa 0.6%. Matsakaicin ruwa yana tsakanin 0.3% da 1%.

Hakanan ana iya gani daga sakamakon gwajin cewa nau'ikan ethers na cellulose daban-daban suna da tasiri daban-daban akan danko na siminti.tushen plaster. Lokacin da maida hankali ne 1%, danko na P2, E2 da H1 nau'i uku na cellulose ether ruwa mafita ne 4990mPa.·s, 5070mPa·S da 5250mPa·S bi da bi, danko na H1 bayani shine mafi girma, amma danko na P2, E2 da H1 nau'ikan ether iri uku na ether-gyaran siminti slurries sun kasance 13800mPa·S, 12900mPa·S da 12700mPa·S bi da bi, kuma danko na H1 gyare-gyaren simintin slurries shine mafi ƙanƙanta. Wannan shi ne saboda ethers cellulose yawanci suna da tasirin jinkirta ciminti hydration. Daga cikin nau'ikan ethers na cellulose guda uku, HEC, HPMC da HEMC, HEC yana da ƙarfi mafi ƙarfi don jinkirta ruwan siminti. Saboda haka, a cikin siminti da aka gyara H1tushen plaster, saboda ƙarancin ciminti hydration, tsarin cibiyar sadarwa na samfuran hydration na ciminti yana haɓaka da hankali, kuma danko shine mafi ƙasƙanci.

2.2 Tasirin adadin juyawa

Daga tasirin saurin juyawa na viscometer akan danko na siminti mai tsabtatushen plaster da kuma cellulose ether gyare-gyaren cimintitushen plaster, ana iya ganin cewa yayin da saurin juyawa ya karu, danko na cellulose ether ya canza siminti.tushen plaster da siminti zallatushen plaster yana raguwa zuwa nau'i daban-daban, wato, dukkansu suna da dukiya na raguwar shear kuma suna cikin ruwan pseudoplastic. Ƙananan juzu'i na juyawa, mafi girma da raguwar danko na duk simintitushen plaster tare da juzu'in juzu'i, wato, mafi bayyane pseudoplasticity na simintitushen plaster. Tare da haɓakar juzu'in juzu'i, lanƙwasa na danko yana raguwa na simintitushen plaster sannu a hankali ya zama mai laushi, kuma pseudoplasticity yana raunana. Idan aka kwatanta da siminti zallatushen plaster, da pseudoplasticity na cellulose ether gyara simintitushen plaster ya fi rauni, wato, haɗawar ether cellulose yana rage pseudoplasticity na siminti.tushen plaster.

Daga tasirin saurin juyawa akan danko na simintitushen plaster a karkashin daban-daban cellulose ether iri da danko, za a iya sani cewa cimintitushen plaster modified da daban-daban cellulose ethers yana da daban-daban pseudoplastic ƙarfi, da kuma karami da danko na cellulose ether, mafi girma da danko na modified siminti.tushen plaster. Mafi bayyanar pseudoplasticity na simintitushen plaster shine; da pseudoplasticity na ciminti da aka gyaratushen plaster ba shi da wani bambanci a bayyane tare da nau'ikan ethers cellulose daban-daban tare da viscosities iri ɗaya. Daga P2, E2 da H1 nau'ikan siminti iri uku na ether da aka gyaratushen plaster a cikin nau'i daban-daban (0.1%, 0.3%, 0.6% da 0.9%), ana iya sanin tasirin saurin juyawa akan danko, P2, E2 da H1 nau'ikan fiber guda uku. : lokacin da adadin cellulose ether ya bambanta, pseudoplasticity su bambanta. Ƙananan adadin ether cellulose, mafi ƙarfin pseudoplasticity na ciminti da aka gyara.tushen plaster.

Bayan siminti yana hulɗa da ruwa, ƙwayoyin simintin da ke saman suna da sauri da sauri, kuma samfurori na hydration (musamman CSH gel) suna samar da tsarin haɓakawa. Lokacin da aka sami karfin juzu'i a cikin bayani, tsarin agglomeration zai buɗe, don haka tare da jagorancin ƙarfin juriya An rage juriya na juriya, ta haka yana nuna dukiya na raguwa. Cellulose ether wani nau'i ne na macromolecule tare da tsarin asymmetric. Lokacin da maganin ya kasance har yanzu, ƙwayoyin ether cellulose na iya samun mabanbanta daban-daban. Lokacin da aka sami ƙarfin juzu'i na jagora a cikin maganin, doguwar sarkar kwayoyin za ta juya ta tafi tare. An rage jagorancin ƙarfin juzu'i, yana haifar da raguwa a cikin juriya na kwarara, kuma yana nuna dukiyar da aka yi da shinge. Idan aka kwatanta da samfuran hydration na siminti, ƙwayoyin ether cellulose sun fi sassauƙa kuma suna da takamaiman ƙarfin buffer don ƙarfi. Saboda haka, idan aka kwatanta da siminti mai tsabtatushen plaster, da pseudoplasticity na cellulose ether gyara simintitushen plaster ya fi rauni, kuma, yayin da danko ko abun ciki na ether cellulose ya karu, tasirin buffering na cellulose ether molecules akan karfi mai karfi ya fi bayyane. Plasticity ya zama mai rauni.

2.3 Tasirin zafin jiki

Daga tasirin canjin zafin jiki (20°C, 27°C da 35°C) a kan danko na cellulose ether ciminti gyaratushen plaster, ana iya ganin cewa lokacin da abun ciki na ether cellulose ya kasance 0.6%, yayin da yawan zafin jiki ya karu, siminti mai tsabta.tushen plaster da M1 Dankowar siminti da aka gyaratushen plaster ya karu, da kuma danko na sauran cellulose ether gyara simintitushen plaster ya ragu, amma raguwa bai yi girma ba, da kuma danko na H1 gyare-gyaren simintitushen plaster ya ragu sosai. Har zuwa simintin E2 da aka gyaratushen plaster yana damuwa, lokacin da rabon polyash shine 0.6%, danko na simintitushen plaster yana raguwa tare da haɓakar zafin jiki, kuma lokacin da rabon polyash shine 0.3%, danko na simintitushen plaster yana ƙaruwa tare da ƙara yawan zafin jiki.

Gabaɗaya magana, saboda raguwar ƙarfin hulɗar intermolecular, dankon ruwan zai ragu tare da haɓakar zafin jiki, wanda shine yanayin maganin ether cellulose. Duk da haka, yayin da zafin jiki ya tashi, kuma lokacin hulɗa tsakanin ciminti da ruwa ya karu, saurin hydration na siminti zai kasance da sauri sosai, kuma matakin hydration zai karu, don haka danko na siminti mai tsabta.tushen plaster zai karu maimakon.

A cikin cellulose ether gyare-gyaren cimintitushen plaster, cellulose ether za a adsorbed zuwa saman siminti hydration kayayyakin, game da shi ya hana ciminti hydration, amma daban-daban iri da kuma adadin cellulose ethers da daban-daban damar iya yin komai don hana ciminti hydration, MC (kamar M1) yana da wani rauni ikon hana ciminti hydration. kuma yayin da yawan zafin jiki ya karu, yawan hydration na simintitushen plaster har yanzu yana da sauri, don haka yayin da zafin jiki ya karu, danko Yana ƙaruwa gaba ɗaya; HEC, HPMC da HEMC na iya hana hydration na ciminti sosai, yayin da yawan zafin jiki ya karu, ƙimar siminti.tushen plaster yana da hankali, don haka yayin da yawan zafin jiki ya ƙaru, HEC, HPMC da HEMC sun canza siminti.tushen plaster (0.6% polyash rabo) an rage gaba ɗaya, kuma saboda ikon HEC don jinkirta ciminti hydration ya fi girma fiye da na HPMC da HEMC, canjin cellulose ether a cikin canjin zafin jiki (20)°C, 27°C da 35°C) Dankowar siminti da aka gyara H1tushen plaster ya ragu sosai tare da karuwar zafin jiki. Duk da haka, ciminti hydration har yanzu yana wanzu lokacin da yawan zafin jiki ya fi girma, don haka matakin raguwar simintin ether da aka gyara.tushen plaster tare da karuwar zafin jiki ba a bayyane yake ba. Har zuwa simintin E2 da aka gyaratushen plaster yana damuwa, lokacin da adadin ya girma (rabin ash shine 0.6%), sakamakon hana ciminti hydration yana bayyane, kuma danko yana raguwa tare da karuwar zafin jiki; lokacin da adadin ya ragu (rabin ash shine 0.3%), sakamakon hana ciminti hydration ba a bayyane yake ba, kuma danko yana ƙaruwa tare da karuwar zafin jiki.

3. Kammalawa

(1) Tare da ci gaba da karuwa na cellulose ether abun ciki, da danko da danko ƙara yawan siminti.tushen plaster ci gaba da karuwa. Tsarin hanyar sadarwa na kwayoyin halitta na cellulose ether da tsarin cibiyar sadarwa na samfuran hydration na ciminti suna haɗuwa, kuma farkon hydration na ciminti yana ƙaruwa da maida hankali na ether cellulose a kaikaice, don haka danko na ether ether cellulose da ciminti.tushen plaster yana da "sakamako mai hadewa", wato, cellulose ether Dankowar siminti da aka gyara.tushen plaster ya fi girma fiye da jimlar dankowar su. Idan aka kwatanta da HPMC da HEMC gyare-gyaren siminti slurries, HEC gyare-gyaren ciminti slurries suna da ƙananan ƙimar gwajin ɗanƙoƙi saboda haɓakar haɓakar ruwa.

(2) Dukansu cellulose ether gyara simintitushen plaster da siminti zallatushen plaster suna da dukiya na raguwa mai laushi ko pseudoplasticity; da pseudoplasticity na cellulose ether gyara simintitushen plaster ya yi ƙasa da na siminti zallatushen plaster; ƙananan juzu'in juzu'i, ko cellulose Ƙananan danko na ether-gyaran simintitushen plaster, ko ƙananan abun ciki na ether cellulose, mafi mahimmancin pseudoplasticity na cellulose ether-gyaran simintitushen plaster.

(3) Yayin da yawan zafin jiki ke ci gaba da hauhawa, saurin da matakin hydration na siminti ya karu, ta yadda dankowar siminti zalla.tushen plaster a hankali yana ƙaruwa. Saboda nau'o'in nau'i daban-daban da adadin ethers cellulose suna da damar daban-daban don hana ciminti hydration, danko na simintin da aka gyara ya bambanta da zafin jiki.