An yi nazarin tasirin abubuwa kamar canjin danko na hydroxyethyl methylcellulose (HEMC), ko an canza shi ko a'a, da canjin abun ciki akan damuwa da yawan amfanin ƙasa da dankon filastik na sabon turmi siminti. Don HEMC wanda ba a canza shi ba, mafi girman danko, rage yawan damuwa na yawan amfanin ƙasa da dankon filastik na turmi; tasirin canjin danko na gyare-gyaren HEMC akan abubuwan rheological na turmi ya raunana; komai ko an gyaggyara ko a'a, mafi girman danko na HEMC, ƙananan ƙananan sakamako na retardation na yawan amfanin ƙasa da ci gaban dankon filastik na turmi ya fi bayyane. Lokacin da abun ciki na HEMC ya fi girma fiye da 0.3%, yawan yawan damuwa da ƙwayar filastik na turmi ya karu tare da karuwar abun ciki; lokacin da abun ciki na HEMC ya girma, yawan damuwa na turmi yana raguwa tare da lokaci, kuma kewayon danko na filastik yana ƙaruwa tare da lokaci.
Mahimman kalmomi: hydroxyethyl methylcellulose, sabon turmi, kaddarorin rheological, yawan damuwa, danko filastik
I. Gabatarwa
Tare da haɓaka fasahar ginin turmi, an ƙara mai da hankali ga aikin injiniyoyi. Harkokin sufuri na tsaye mai nisa yana gabatar da sabbin buƙatu don turmi da aka yi famfo: dole ne a kiyaye ruwa mai kyau a duk lokacin aikin famfo. Wannan yana buƙatar yin nazarin abubuwan da ke tasiri da yanayin ƙuntatawa na ruwa na turmi, kuma hanyar gama gari ita ce kiyaye sigogin rheological na turmi.
Abubuwan rheological na turmi sun dogara ne akan yanayi da adadin albarkatun ƙasa. Cellulose ether wani abu ne da ake amfani da shi sosai a cikin turmi na masana'antu, wanda ke da tasiri mai yawa akan rheological Properties na turmi, don haka masana a gida da waje sun gudanar da bincike akai. A taƙaice, za a iya yanke shawara masu zuwa: karuwa a cikin adadin cellulose ether zai haifar da karuwa a farkon karfin turmi, amma bayan wani lokaci na motsawa, juriya na turmi zai ragu a maimakon (1). ; lokacin da ruwa na farko ya kasance iri ɗaya ne, za a fara rasa yawan ruwan turmi. ya karu bayan raguwa (2); Ƙarfin amfanin gona da dankon filastik na turmi ya nuna yanayin raguwa da farko sannan kuma yana ƙaruwa, kuma ether cellulose ya inganta lalata tsarin turmi kuma ya tsawaita lokaci daga lalacewa zuwa sake ginawa (3); Ether da thickened foda suna da mafi girma danko da kwanciyar hankali da dai sauransu (4). Koyaya, binciken da ke sama har yanzu yana da gazawa:
Ma'auni da tsarin ma'auni na masana daban-daban ba daidai ba ne, kuma ba za a iya kwatanta sakamakon gwajin daidai ba; gwajin gwaji na kayan aiki yana iyakance, kuma ma'auni na rheological na turmi da aka auna yana da ƙananan bambance-bambance, wanda ba shi da wakilci; akwai ƙarancin gwaje-gwajen kwatancen akan ethers cellulose tare da viscosities daban-daban; Akwai abubuwa da yawa masu tasiri, kuma maimaitawar ba ta da kyau. A cikin 'yan shekarun nan, bayyanar da Viskomat XL turmi rheometer ya ba da babban dacewa don daidaitaccen ƙaddarar kaddarorin rheological na turmi. Yana da abũbuwan amfãni na babban matakin sarrafawa ta atomatik, babban ƙarfin aiki, faffadan gwajin gwaji, da sakamakon gwaji fiye da layi tare da ainihin yanayi. A cikin wannan takarda, dangane da amfani da wannan nau'in kayan aiki, an haɗa sakamakon bincike na malaman da ake da su, kuma an tsara shirin gwajin don nazarin tasirin nau'o'in nau'i daban-daban da kuma viscosities na hydroxyethyl methylcellulose (HEMC) a kan rheology na turmi a ciki. mafi girman adadin sashi. tasiri tasiri.
2. Rheological samfurin sabon siminti turmi
Tun lokacin da aka shigar da ilimin rheology a cikin siminti da kimiyyar kankare, bincike da yawa sun nuna cewa sabon siminti da turmi ana iya ɗaukarsa azaman ruwan Bingham, kuma Banfill ya ƙara fayyace yuwuwar yin amfani da ƙirar Bingham don bayyana halayen rheological na turmi (5). A cikin ma'auni na rheological τ=τ0+μγ na samfurin Bingham, τ shine damuwa mai ƙarfi, τ0 shine damuwa na yawan amfanin ƙasa, μ shine danko na filastik, kuma γ shine girman shear. Daga cikin su, τ0 da μ sune ma'auni guda biyu mafi mahimmanci: τ0 shine mafi ƙarancin damuwa wanda zai iya sa turmin siminti ya gudana, kuma kawai lokacin da τ>τ0 ya yi aiki a kan turmi, turmi zai iya gudana; μ yana nuna juriya mai danko lokacin da turmi ke gudana Yawan girma μ, a hankali turmi yana gudana [3]. A cikin yanayin da duka τ0 da μ ba a san su ba, dole ne a auna damuwa mai ƙarfi aƙalla nau'i biyu daban-daban na shear kafin a iya ƙididdige shi (6).
A cikin rheometer turmi da aka ba da, madaidaicin NT da aka samu ta saita ƙimar jujjuya ruwa N da auna ƙarfin T da ƙarfin juriya na turmi kuma ana iya amfani dashi don ƙididdige wani ma'auni T=g+ wanda ya dace da ƙirar Bingham Simitoci guda biyu g da h na Nh. g yana daidai da yawan karuwar yawan amfanin ƙasa τ0, h yana daidai da dankon filastik μ, da τ0 = (K / G) g, μ = ( l / G ) h , inda G ke da alaka da kayan aiki, kuma K zai iya za a wuce ta hanyar da aka sani Ana samun ta ta hanyar gyara ruwan da halayensa suka canza tare da adadin shear[7]. Don dacewa, wannan takarda ta tattauna g da h kai tsaye, kuma tana amfani da canjin dokar g da h don nuna canjin canjin yawan amfanin ƙasa da dankon roba na turmi.
3. Gwaji
3.1 Kayan danye
3.2 ruwa
Yashi ma'adini: yashi mai laushi shine raga 20-40, matsakaicin yashi shine raga 40-70, yashi mai kyau shine raga 70-100, kuma ana haɗe ukun a cikin rabo na 2:2:1.
3.3 Cellulose ether
Hydroxyethyl methylcellulose HEMC20 (danko 20000 mPa s), HEMC25 (dankowa 25000 mPa s), HEMC40 (danko 40000 mPa s), da HEMC45 (danko 45000 mPa s), wanda HEMC25 ne modified.
3.4 Hada ruwa
famfo ruwa.
3.5 Tsarin gwaji
Matsakaicin lemun tsami-yashi shine 1: 2.5, ana amfani da ruwa akan 60% na ciminti, kuma abun ciki na HEMC shine 0-1.2% na ciminti.
Da farko a haxa siminti daidai gwargwado, HEMC da yashi quartz daidai gwargwado, sannan a zuba ruwan gauraya bisa ga GB/T17671-1999 sannan a jujjuya, sannan a yi amfani da na’urar romi Viskomat XL don gwadawa. Hanyar gwajin ita ce: saurin yana ƙaruwa daga 0 zuwa 80rpm a 0 ~ 5min, 60rpm a 5 ~ 7min, 40rpm a 7 ~ 9min, 20rpm a 9 ~ 11min, 10rpm a 11 ~ 13min, da 5rpm a 13 ~ 15min. 15 ~ 30min, gudun shine 0rpm, sannan a sake zagayowar sau ɗaya kowane 30min bisa ga tsarin da ke sama, kuma jimlar gwajin shine 120min.
4. Sakamako da tattaunawa
4.1 Sakamakon HEMC danko canji a kan rheological Properties na siminti turmi
(Yawan adadin HEMC shine 0.5% na yawan siminti), daidai yake nuna ka'idar bambance-bambancen damuwa na yawan amfanin ƙasa da dankon filastik na turmi. Ana iya ganin cewa ko da yake danko na HEMC40 ya fi na HEMC20, yawan yawan amfanin ƙasa da dankon filastik na turmi da aka haɗe da HEMC40 sun fi ƙasa da na turmi da aka haɗe da HEMC20; ko da yake danko na HEMC45 yana da 80% sama da na HEMC25, yawan damuwa na turmi ya dan ragu kadan, kuma dankon filastik yana tsakanin Bayan mintuna 90 an sami karuwa. Wannan saboda girman dankon ether na cellulose, yana rage saurin narkewa, kuma yana ɗaukar tsayin daka don turmi da aka shirya tare da shi don isa danko na ƙarshe [8]. Bugu da kari, a daidai lokacin da ake gwajin, yawan turmin da aka hada da HEMC40 ya yi kasa da na turmin da aka hada da HEMC20, sannan na turmin da aka hada da HEMC45 ya yi kasa da na turmin da aka hada da HEMC25. yana nuna cewa HEMC40 da HEMC45 sun gabatar da ƙarin kumfa na iska, kuma kumfa na iska a cikin turmi yana da tasirin "Ball", wanda kuma yana rage juriya na turmi.
Bayan ƙara HEMC40, yawan damuwa na turmi ya kasance cikin daidaito bayan mintuna 60, kuma dankon filastik ya karu; bayan ƙara HEMC20, yawan yawan amfanin turmi ya kai ma'auni bayan mintuna 30, kuma ɗanƙoƙin filastik ya ƙaru. Ya nuna cewa HEMC40 yana da tasiri mai girma na jinkirtawa akan haɓaka yawan yawan turmi da damuwa da dankon filastik fiye da HEMC20, kuma yana ɗaukar lokaci mai tsawo don isa ga danko na ƙarshe.
Matsakaicin yawan amfanin ƙasa na turmi gauraye da HEMC45 ya ragu daga 0 zuwa mintuna 120, kuma dankon filastik ya karu bayan mintuna 90; yayin da yawan amfanin ƙasa na turmi gauraye da HEMC25 ya karu bayan mintuna 90, kuma dankon filastik ya karu bayan mintuna 60. Ya nuna cewa HEMC45 yana da tasiri mai girma na jinkirin haɓakar haɓakar turmi da damuwa da dankon filastik fiye da HEMC25, kuma lokacin da ake buƙata don isa danko na ƙarshe kuma ya fi tsayi.
4.2 Tasirin abun ciki na HEMC akan yawan damuwa na turmi siminti
A lokacin gwajin, abubuwan da ke shafar yawan damuwa na turmi sune: lalata turmi da zub da jini, lalacewar tsarin ta hanyar motsa jiki, samuwar samfuran ruwa, rage danshi kyauta a turmi, da kuma rage tasirin ether cellulose. Don sakamakon retarding na cellulose ether, mafi yawan yarda da ra'ayi shine a bayyana shi ta hanyar tallan kayan ado.
Ana iya ganin cewa lokacin da aka ƙara HEMC40 kuma abun ciki bai wuce 0.3% ba, yawan damuwa na turmi yana raguwa a hankali tare da karuwar abun ciki na HEMC40; lokacin da abun ciki na HEMC40 ya fi 0.3% girma, ƙarfin turmi yana ƙaruwa a hankali. Saboda zub da jini da delamination na turmi ba tare da cellulose ether, babu isasshen siminti manna tsakanin aggregates da man shafawa, haifar da karuwa a yawan amfanin ƙasa danniya da wahala a kwarara. Ingantacciyar haɓakar ether ɗin cellulose na iya inganta yanayin haɓakar turmi yadda ya kamata, kuma kumfa da aka gabatar na iska daidai yake da ƴan ƴan ƙwallo, waɗanda za su iya rage yawan damuwa na turmi kuma ya sauƙaƙa kwarara. Yayin da abun ciki na ether cellulose ke ƙaruwa, ƙayyadaddun danshi kuma yana ƙaruwa a hankali. Lokacin da abun ciki na ether cellulose ya wuce wani ƙima, tasirin raguwar danshi na kyauta ya fara taka muhimmiyar rawa, kuma yawan damuwa na turmi yana karuwa a hankali.
Lokacin da adadin HEMC40 ya kasance ƙasa da 0.3%, yawan damuwa na turmi yana raguwa sannu a hankali a cikin 0-120min, wanda galibi yana da alaƙa da haɓakar haɓakar turmi, saboda akwai tazara tsakanin ruwa da kasan. kayan aiki, da tarawa bayan delamination nutsewa zuwa kasa, juriya na sama ya zama karami; lokacin da abun ciki na HEMC40 ya kasance 0.3%, turmi ba zai daɗe ba, adsorption na ether cellulose yana iyakance, hydration yana da rinjaye, kuma yawan damuwa yana da karuwa; abun ciki na HEMC40 shine Lokacin da abun ciki na ether cellulose ya kasance 0.5% -0.7%, adsorption na ether cellulose yana ƙaruwa a hankali, ƙimar hydration yana raguwa, kuma yanayin ci gaba na yawan damuwa na turmi ya fara canzawa; A saman, adadin hydration yana da ƙasa kuma yawan damuwa na turmi yana raguwa tare da lokaci.
4.3 Tasirin abun ciki na HEMC akan dankowar filastik na turmi siminti
Ana iya ganin cewa bayan ƙara HEMC40, dankon filastik na turmi yana ƙaruwa sannu a hankali tare da karuwar abubuwan HEMC40. Wannan shi ne saboda cellulose ether yana da sakamako mai kauri, wanda zai iya ƙara danko na ruwa, kuma mafi girma sashi, mafi girma danko na turmi. Dalilin da yasa dankon filastik na turmi ya ragu bayan ƙara 0.1% HEMC40 shi ma saboda tasirin "ball" na gabatarwar kumfa na iska, da kuma rage zubar jini da delamination na turmi.
Dankin filastik na turmi na yau da kullun ba tare da ƙara ether cellulose ba a hankali yana raguwa tare da lokaci, wanda kuma yana da alaƙa da ƙananan ƙarancin ɓangaren sama wanda ya haifar da shimfidar turmi; lokacin da abun ciki na HEMC40 ya kasance 0.1% -0.5%, tsarin turmi yana da ɗanɗano, kuma tsarin turmi yana da ɗanɗano bayan mintuna 30. Dankin filastik baya canzawa da yawa. A wannan lokacin, yafi nuna tasirin danko na ether cellulose kanta; bayan abun ciki na HEMC40 ya fi 0.7%, ƙwayar filastik na turmi yana ƙaruwa sannu a hankali tare da karuwar lokaci, saboda danko na turmi yana da alaka da na cellulose ether. Dankowar maganin ether cellulose yana ƙaruwa a hankali a cikin ɗan lokaci bayan fara haɗuwa. Mafi girman sashi, mafi mahimmancin tasirin haɓaka tare da lokaci.
V. Kammalawa
Abubuwa irin su canjin danko na HEMC, ko an canza shi ko a'a, da kuma canjin sashi zai tasiri tasirin rheological na turmi, wanda za'a iya nunawa ta hanyar sigogi biyu na damuwa na yawan amfanin ƙasa da dankon filastik.
Don HEMC wanda ba a canza shi ba, mafi girman danko, rage yawan damuwa da kuma dankon filastik na turmi a cikin 0-120min; Tasirin canjin danko na HEMC da aka gyara akan abubuwan rheological na turmi ya fi rauni fiye da na HEMC wanda ba a canza shi ba; Komai gyare-gyare Ko yana da dindindin ko a'a, mafi girman danko na HEMC, mafi mahimmancin sakamako na jinkirtawa akan ci gaban yawan yawan turmi da dankon filastik.
Lokacin ƙara HEMC40 tare da danko na 40000mPa·s kuma abun ciki ya fi 0.3% girma, yawan damuwa na turmi yana ƙaruwa a hankali; lokacin da abun ciki ya wuce 0.9%, yawan damuwa na turmi ya fara nuna yanayin raguwa a hankali tare da lokaci; Dankin filastik yana ƙaruwa tare da haɓaka abun ciki na HEMC40. Lokacin da abun ciki ya fi 0.7%, dankon filastik na turmi ya fara nuna yanayin karuwa a hankali tare da lokaci.
Lokacin aikawa: Nuwamba-24-2022