Focus on Cellulose ethers

Kayayyakin Injini na Cellulose Ether An Gyara don Turmi Siminti

Kayayyakin Injini na Cellulose Ether An Gyara don Turmi Siminti

An gyara turmi ciminti tare da rabon ruwa-ciminti na 0.45, rabon lemun tsami-yashi na 1:2.5, da cellulose ether tare da viscosities daban-daban na 0%, 0.2%, 0.4%, 0.6%, 0.8%, da 1.0% an shirya. . Ta hanyar auna kayan aikin injiniya na turmi siminti da kuma lura da ƙananan ƙwayoyin cuta, an yi nazarin tasirin HEMC akan ƙarfin matsawa, ƙarfin sassauƙa da ƙarfin haɗin gwiwa na gyare-gyaren turmi siminti. Sakamakon binciken ya nuna cewa: tare da karuwar abubuwan da ke cikin HEMC, ƙarfin matsawa na turmi da aka gyara a shekaru daban-daban yana raguwa ci gaba, kuma raguwa yana raguwa kuma yana kula da zama mai laushi; Lokacin da aka ƙara irin wannan abun ciki na ether cellulose, Ƙarfin da aka gyara na cellulose ether da aka gyara tare da viscosities daban-daban shine: HEMC20 Bayani na HEMC10>HEMC5.

Mabuɗin kalmomi:ether cellulose; turmi siminti; ƙarfin matsawa; ƙarfin sassauƙa; ƙarfin haɗin gwiwa

 

1 Gabatarwa

A wannan mataki, buƙatun turmi na shekara-shekara a duniya ya zarce tan miliyan 200, kuma har yanzu buƙatun masana'antu na karuwa. A halin yanzu, turmi siminti na gargajiya yana da lahani kamar zubar jini, lalatawa, raguwar bushewa mai yawa, ƙarancin rashin ƙarfi, ƙarancin ƙarfi, da rashin cika ruwa saboda asarar ruwa, waɗanda ke da wahalar warwarewa, ba kawai yana haifar da lahani ba, har ma yana haifar da lahani. don taurara Al'amura irin su fashewar turmi, tarwatsawa, zubarwa, da fashe suna faruwa.

A matsayin daya daga cikin admixtures da aka fi amfani da shi don turmi kasuwanci, cellulose ether yana da ayyuka na riƙewar ruwa, daɗaɗawa da jinkirtawa, kuma ana iya amfani dashi don inganta halayen jiki na simintin turmi kamar aiki, riƙe ruwa, aikin haɗin gwiwa, da saita lokaci. , kamar haɓakar siminti mai mahimmanci. Ƙarfin haɗin ɗamara na turmi za a rage, amma ƙarfin matsawa, ƙarfin sassauƙa da na roba na turmi siminti za a rage. Zhang Yishun da sauransu sun yi nazari kan tasirin methyl cellulose ether da hydroxypropyl methyl cellulose ether akan kaddarorin turmi. Sakamakon ya nuna cewa: duka ethers cellulose na iya inganta riƙon ruwa na turmi, da ƙarfin flexural da Ƙarfin matsawa yana raguwa a cikin digiri daban-daban, yayin da rabo na nadawa da ƙarfin haɗin gwiwar turmi ya karu a digiri daban-daban, da kuma raguwar aikin turmi zai iya. a inganta. AJenni, R.Zurbriggen, da dai sauransu sun yi amfani da gwaje-gwajen gwaje-gwaje na zamani da dabarun bincike don nazarin hulɗar abubuwa daban-daban a cikin ether cellulose ether gyare-gyare na bakin ciki-Layer m turmi tsarin, kuma sun lura cewa cellulose ether da Ca (OH) sun bayyana a kusa da saman turmi. . 2, yana nuna ƙaura na ethers cellulose a cikin kayan da ke da siminti.

A cikin wannan takarda, ta yin amfani da hanyoyin gwajin turmi irin su juriya na matsawa, juriya mai sassauci, haɗin kai, da bayyanar microscopic SEM, tasirin simintin siminti na cellulose ether akan kaddarorin inji kamar ƙarfin matsawa, juriya, da ƙarfin haɗin gwiwa a shekaru daban-daban. kuma an bayyana shi. tsarin aikinsa.

 

2. Kayan albarkatun kasa da hanyoyin gwaji

2.1 Kayan danye

2.1.1 Siminti

Simintin laurate na yau da kullun wanda Wuhan Huaxin Cement Co., Ltd., samfurin P 042.5 (GB175-2007), ke da nauyin 3.25g/cm³ da wani yanki na musamman na 4200cm²/g.

2.1.2 Hydroxypropyl methylcellulose ether

Thehydroxyethyl methyl cellulose etherƘungiyoyin Hercules na Amurka suka samar suna da danko na 50000MPa/s, 100000MPa/s, da 200000MPa/s a cikin 2% bayani a 25°C, kuma gajarce masu zuwa sune HEMC5, HEMC10, da HEMC20.

2.2 Hanyar gwaji

a. Ƙarfin turmi da aka gyara

An gwada ƙarfin damtse na koren samfuran jiki tare da injin ƙarfin ƙarfi na TYE-300 daga Wuxi Jianyi Instrument Co., Ltd. Adadin lodi shine 0.5 kN/s. Ana yin gwajin ƙarfin matsawa bisa ga GB/T17671-1999 “Hanyar Gwajin Ƙarfin Ƙarfin Siminti (Hanyar ISO)”.

Ta hanyar ma'anar, dabarar ƙididdige ƙarfin matsi na jikin kore shine:

Rc=F/S

Ku Rc-karfin matsawa, MPa;

F-nauyin gazawar da ke aiki akan samfurin, kN;

S-wurin matsa lamba, m².

Ta hanyar ma'anar, dabara don ƙididdige ƙarfin sassauƙa na jikin kore shine:

Rf= (3P× L)/(2b× h²= 0.234×P

A cikin tsari, Rf-Ƙarfin sassauƙa, MPa;

P-nauyin gazawar da ke aiki akan samfurin, kN;

L-nisa tsakanin cibiyoyin silinda masu tallafawa, wato, 10cm;

b, h-nisa da tsayin sashin giciye na jikin gwajin, duka biyun sun kai 4cm.

b. Ƙarfin haɗin ɗamara na turmi siminti da aka gyara

Yi amfani da ZQS6-2000 Adhesive Brick Adhesive Strength Detector don auna ƙarfin mannewa, kuma saurin jujjuyawar shine 2mm/min. An gudanar da gwajin ƙarfin haɗin kai bisa ga JC/T985-2005 "tumi mai daidaita kai na ciminti don ƙasa".

Ta hanyar ma'anar, dabarar ƙididdige ƙarfin haɗin gwiwa na jikin kore shine:

P=F/S

A cikin tsari, P-Ƙarfin haɗin gwiwa, MPa;

F-matsakaicin nauyin gazawar, N;

S-yankin haɗin gwiwa, mm².

 

3. Sakamako da tattaunawa

3.1 Ƙarfin matsi

Daga ƙarfin matsawa na nau'i biyu na cellulose ether gyare-gyaren turmi tare da viscosities daban-daban a cikin shekaru daban-daban, ana iya ganin cewa tare da karuwar abun ciki na HEMC, ƙarfin matsawa na cellulose ether modified turmi a shekaru daban-daban (3d, 7d da 28d) ya ragu. muhimmanci. Ya ragu sosai kuma a hankali ya daidaita: lokacin da abun ciki na HEMC ya kasance ƙasa da 0.4%, ƙarfin matsawa ya ragu sosai idan aka kwatanta da samfurin mara kyau; lokacin da abun ciki na HEMC ya kasance 0.4% ~ 1.0%, yanayin raguwar ƙarfin matsawa ya ragu. Lokacin da abun ciki na ether cellulose ya fi 0.8%, ƙarfin matsawa na shekarun 7d da 28d yana ƙasa da na samfurin blank a shekarun 3d, yayin da ƙarfin matsawa na turmi 3d da aka gyara ya kusan kusan sifili, kuma samfurin shine. daskare da sauƙi Nan take an murkushe shi, ciki ya zama foda, kuma yawan ya yi ƙasa kaɗan.

Tasirin HEMC guda ɗaya akan ƙarfin matsawa na turmi da aka gyara a shekaru daban-daban shima ya bambanta, yana nuna cewa ƙarfin matsawa na 28d yana raguwa tare da haɓaka abubuwan HEMC fiye da na 7d da 3d. Wannan yana nuna cewa tasirin HEMC ya kasance koyaushe tare da karuwar shekaru, kuma tasirin HEMC bai shafi raguwar ruwa a cikin tsarin ba ko ci gaba da amsawar hydration, yana haifar da haɓaka ƙarfin matsawa. na turmi da aka gyara yana da ƙanƙanta fiye da wancan ba tare da samfuran Turmi gauraye da HEMC ba.

Daga canjin yanayin ƙarfin matsa lamba na cellulose ether modified turmi a shekaru daban-daban, ana iya ganin cewa lokacin da aka ƙara adadin adadin ether iri ɗaya, ƙarfin matsawa na ether da aka gyara turmi tare da viscosities daban-daban shine: HEMC20 Bayani na HEMC10>HEMC5. Wannan shi ne saboda HEMC tare da babban digiri na polymerization yana da tasiri mafi girma akan rage ƙarfin ƙarfin turmi fiye da HEMC tare da ƙananan digiri na polymerization, amma ƙarfin matsawa na turmi da aka gyara tare da HEMC yana da ƙasa da ƙasa fiye da na blank turmi ba tare da HEMC ba.

Abubuwa uku masu zuwa suna haifar da raguwar ƙarfin matsa lamba na turmi da aka gyara: a gefe guda, saboda tsarin hanyar sadarwa na HEMC mai narkewa na ruwa yana rufe simintin siminti, CSH gel, calcium oxide, calcium aluminate hydrate da sauran barbashi da rashin ruwa. barbashi A saman, musamman a farkon matakin ciminti hydration, adsorption tsakanin calcium aluminate hydrate da HEMC yana rage jinkirin hydration na calcium aluminate, yana haifar da raguwa mai yawa a cikin ƙarfin matsawa. Sakamakon retarding na turmi na dindindin a bayyane yake, wanda ke nuna cewa lokacin da abun ciki na HEMC20 ya kai 0.8% ~ 1%, ƙarfin 3d na samfurin turmi da aka gyara shine sifili; a daya bangaren kuma, hydrated HEMC Maganin yana da danko mafi girma, kuma A Lokacin da ake hada turmi, ana iya hada shi da iska don samar da kumfa mai yawa na iska, wanda hakan ya haifar da adadi mai yawa a cikin turmi mai tauri. , kuma ƙarfin matsawa na samfurin yana raguwa ci gaba tare da haɓakar abun ciki na HEMC da karuwar digiri na polymerization; Tsarin turmi kawai yana ƙara sassaucin turmi kuma ba zai iya taka rawar goyon baya mai ƙarfi ba, don haka ƙarfin matsawa yana raguwa.

3.2 Ƙarfin sassauƙa

Daga ƙarfin flexural na biyu daban-daban danko cellulose ether modified turmi a shekaru daban-daban, za a iya gani cewa kama da canji a cikin matsawa ƙarfi na modified turmi, da flexural ƙarfi na cellulose ether modified turmi sannu a hankali rage tare da karuwa da HEMC abun ciki.

Daga canjin canjin ƙarfin gyare-gyare na cellulose ether wanda aka gyara turmi a shekaru daban-daban, ana iya ganin cewa lokacin da abun ciki na ether cellulose ya kasance iri ɗaya, ƙarfin flexural na HEMC20 wanda aka gyara samfurin turmi ya ɗan ƙasa da na HEMC10 wanda aka gyara turmi samfurin, yayin da abun ciki na HEMC ya kasance 0.4% ~ 0.8%, 28d ƙarfin jujjuyawar ƙarfin canzawa na biyu kusan sun dace.

Daga canjin canjin ƙarfin gyare-gyare na cellulose ether da aka gyara turmi a shekaru daban-daban, ana iya ganin cewa canjin ƙarfin ƙarfin da aka gyara shine: HEMC5.

3.3 Ƙarfin haɗin gwiwa

Ana iya gani daga bambance-bambancen nau'i na ƙarfin haɗin kai na uku cellulose ether gyare-gyaren turmi a shekaru daban-daban cewa ƙarfin haɗin gwiwa na turmi da aka gyara yana ƙaruwa tare da karuwar abun ciki na HEMC kuma a hankali yana kula da kwanciyar hankali. Tare da haɓaka shekaru, ƙarfin haɗin gwiwa na turmi da aka gyara shima ya nuna haɓakar haɓaka.

Ana iya gani daga 28-day bond ƙarfi canje-canje masu lankwasa na uku cellulose ether gyara turmi cewa ƙarfin haɗin gwiwa na gyare-gyaren turmi yana ƙaruwa tare da haɓakar abun ciki na HEMC, kuma a hankali yana kula da kwanciyar hankali. A lokaci guda, tare da karuwa da digiri na polymerization na cellulose ether, canjin ƙarfin haɗin gwiwa na turmi da aka gyara shine: HEMC20>HEMC10>HEMC5.

Wannan shi ne saboda gabatarwar da yawa na pores a cikin turmi da aka gyare-gyare tare da babban abun ciki na HEMC, wanda ya haifar da karuwa na porosity na jiki mai taurara, raguwar girman tsarin, da jinkirin haɓakar ƙarfin haɗin gwiwa. ; a cikin gwajin gwagwarmaya, raguwa ya faru a cikin turmi da aka gyara A ciki, babu wani karaya a wurin hulɗar tsakanin turmi da aka gyara da substrate, wanda ke nuna cewa ƙarfin haɗin gwiwa tsakanin turmi da aka gyara da substrate ya fi girma fiye da na taurare. turmi gyara. Duk da haka, lokacin da adadin HEMC ya ragu (0% ~ 0.4%), kwayoyin HEMC masu narkewa na ruwa zasu iya rufewa da kuma nannade a kan hydrated siminti barbashi, da kuma samar da wani polymer fim tsakanin siminti barbashi, wanda ya kara da sassauci da kuma sassauci na turmi da aka gyara. Plasticity, kuma saboda kyakkyawar riƙewar ruwa na HEMC, turmi da aka gyara yana da isasshen ruwa don amsawar hydration, wanda ke tabbatar da haɓaka ƙarfin siminti, kuma ƙarfin haɗin gwiwar gyare-gyaren simintin siminti yana ƙaruwa a layi.

3.4 SEM

Daga Hotunan kwatanta SEM kafin da kuma bayan cellulose ether gyare-gyaren turmi, ana iya ganin cewa rata tsakanin ƙwayar kristal a cikin turmi da ba a canza ba yana da girma, kuma an samar da ƙananan lu'ulu'u. A cikin turmi da aka gyara, lu'ulu'u suna girma sosai, haɗakar da ether na cellulose yana inganta aikin riƙe ruwa na turmi, simintin ya cika ruwa sosai, kuma samfuran hydration suna bayyane.

Wannan shi ne saboda cellulose ether an bi da shi tare da tsari na musamman na etherification, wanda ke da kyakkyawan tarwatsawa da ruwa. Ana fitar da ruwan a hankali na tsawon lokaci mai tsawo, ruwa kaɗan ne kawai ke tserewa daga ramukan capillary saboda bushewa da ƙafewa, kuma yawancin ruwan yana yin ruwa da siminti don tabbatar da ƙarfin turmin siminti da aka gyara.

 

4 Kammalawa

a. Yayin da abun ciki na HEMC ya karu, ƙarfin matsawa na turmi da aka gyara a cikin shekaru daban-daban yana raguwa a ci gaba, kuma kewayon raguwa yana raguwa kuma ya kasance mai laushi; lokacin da abun ciki na ether cellulose ya fi girma fiye da 0.8%, 7d da 28d Ƙarfin ƙwaƙwalwa na samfurin 3d-shekaru maras kyau ya fi ƙasa da na samfurin blank, yayin da 3d-shekarin matsa lamba na gyare-gyaren turmi ya kusan zero. Samfurin yana karya lokacin da aka danna shi da sauƙi, kuma ciki yana da foda tare da ƙananan yawa.

b. Lokacin da aka ƙara adadin adadin ether ɗin cellulose, ƙarfin matsa lamba na ether da aka gyara turmi tare da viscosities daban-daban yana canzawa kamar haka: HEMC20 Bayani na HEMC10>HEMC5.

c. Ƙarfin gyare-gyare na cellulose ether gyare-gyaren turmi yana raguwa a hankali tare da karuwar abun ciki na HEMC. Canjin ƙarfin sassauƙa na turmi da aka gyara shine: HEMC5

d. Ƙarfin haɗin gwiwa na turmi da aka gyara yana ƙaruwa tare da haɓaka abun ciki na HEMC, kuma a hankali yakan zama barga. A lokaci guda, tare da karuwa da digiri na polymerization na cellulose ether, canjin ƙarfin haɗin gwiwa na turmi da aka gyara shine: HEMC20>HEMC10>HEMC5.

e. Bayan da aka haxa ether cellulose a cikin turmi siminti, kristal ya girma sosai, an rage ramukan da ke tsakanin hatsin kristal, kuma siminti ya cika ruwa sosai, wanda ke tabbatar da ƙarfin matsawa, sassauƙa da haɗin kai na turmi siminti.

 


Lokacin aikawa: Janairu-30-2023
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