Cellulose ether akan turmi mai daidaita kai

Sakamakonhydroxypropyl methyl cellulose etherakan ruwa, riƙe ruwa da ƙarfin haɗin kai na turmi mai daidaita kai an yi nazarin. Sakamakon ya nuna cewa HPMC na iya inganta ingantaccen ruwa na turmi mai daidaita kai da rage daidaiton turmi. Gabatarwar HPMC na iya inganta ƙarfin haɗin gwiwa na turmi, amma ƙarfin matsawa, ƙarfin sassauƙa da ruwa yana raguwa. An gudanar da gwajin bambanci na SEM akan samfurori, da kuma tasirin HPMC akan tasirin retarding, tasirin ruwa da ƙarfin turmi an kara bayyana shi daga tsarin hydration na ciminti a 3 da 28 kwanaki.

Mabuɗin kalmomi:turmi matakin kai; Cellulose ether; Ruwan ruwa; Riƙewar ruwa

0. Gabatarwa

Kai matakin turmi iya dogara da kansa nauyi samar da wani lebur, santsi da kuma karfi tushe a kan substrate, don haka kamar yadda ya sa ko bond wasu kayan, kuma zai iya gudanar da wani babban yanki na high dace yi, sabili da haka, high liquidity ne siffa mai mahimmanci na turmi mai daidaita kai; Musamman a matsayin babban girma, ƙarfafa mai yawa ko rata ƙasa da 10 mm cikon baya ko ƙarfafa amfani da kayan grouting. Baya ga ruwa mai kyau, turmi mai daidaita kai dole ne ya kasance yana da takamaiman riƙon ruwa da ƙarfin haɗin gwiwa, babu abin da ya faru na rabuwar jini, kuma yana da halayen adiabatic da ƙarancin zafin jiki.

Gabaɗaya, turmi mai daidaita kai yana buƙatar ruwa mai kyau, amma ainihin ruwan simintin slurry yawanci shine 10 ~ 12 cm kawai. Turmi mai daidaita kai na iya zama mai haɗa kai, kuma lokacin saitin farko yana da tsayi kuma lokacin saitin ƙarshe gajere ne. Cellulose ether ne daya daga cikin manyan Additives na shirye-mixed turmi, ko da yake Bugu da kari adadin ne sosai low, amma zai iya muhimmanci inganta yi na turmi, zai iya inganta daidaito na turmi, aiki yi, bonding yi da kuma ruwa riƙewa yi, yana da. muhimmiyar rawa a fagen shirye-shiryen turmi mai gauraya.

1. Kayan albarkatun kasa da hanyoyin bincike

1.1 Raw Materials

(1) P · O 42.5 siminti mai daraja.

(2) Sand abu: Xiamen wanke yashi teku, barbashi size ne 0.3 ~ 0.6mm, ruwa abun ciki ne 1% ~ 2%, wucin gadi bushewa.

(3) Cellulose ether: hydroxypropyl methyl cellulose ether shine samfurin hydroxyl wanda aka maye gurbinsu da methoxy da hydroxypropyl, bi da bi, tare da danko na 300mpa·s. A halin yanzu, yawancin ether cellulose da ake amfani da su shine hydroxypropyl methyl cellulose ether da hydroxyethyl methyl cellulose ether.

(4) superplasticizer: polycarboxylic acid superplasticizer.

(5) Redispersible latex foda: HW5115 jerin samar da Henan Tiansheng Chemical Co., Ltd. ne mai redispersible latex foda copolymerized by VAC/VeoVa.

1.2 Hanyoyin gwaji

An gudanar da gwajin daidai da ma'auni na masana'antu JC/T 985-2005 "Turmi-tushen Siminti don Amfani da ƙasa". An ƙayyade lokacin saitin ta hanyar yin la'akari da daidaitattun daidaito da lokacin saita lokaci na siminti na JC/T 727. Samfuran turmi mai daidaita kai, lankwasawa da gwajin ƙarfin matsawa yana nufin GB/T 17671. Hanyar gwaji na ƙarfin haɗin gwiwa: An shirya shingen gwajin turmi na 80mmx80mmx20mm a gaba, kuma shekarunsa sun wuce 28d. Fitar ta yi taurin kai, kuma ana goge ruwan da ke saman saman bayan jika na minti 10. Ana zubo gunkin gwajin turmi a saman da aka goge tare da girman 40mmx40mmx10mm. Ana gwada ƙarfin haɗin gwiwa a shekarun ƙira.

An yi amfani da sikanin microscopy na lantarki (SEM) don nazarin yanayin halittar kayan siminti a cikin slurry. A cikin binciken, hanyar hada dukkan kayan foda ita ce: na farko, ana hada kayan foda na kowane bangare daidai gwargwado, sannan a zuba a cikin ruwan da ake son hadawa. An yi nazarin tasirin ether na cellulose akan turmi mai daidaita kai ta hanyar ƙarfi, riƙewar ruwa, ruwa da gwaje-gwajen microscopic SEM.

2. Sakamako da bincike

2.1 Motsi

Cellulose ether yana da tasiri mai mahimmanci akan riƙewar ruwa, daidaito da kuma aikin gina turmi mai daidaita kai. Musamman a matsayin turmi mai daidaita kai, ruwa yana ɗaya daga cikin manyan maƙasudai don kimanta aikin turmi mai daidaita kai. A kan jigo na tabbatar da al'ada abun da ke ciki na turmi, za a iya daidaita yawan ruwa na turmi ta hanyar canza abun ciki na ether cellulose.

Tare da haɓaka abun ciki na ether cellulose. Ruwan turmi yana raguwa a hankali. Lokacin da adadin ya kasance 0.06%, yawan ruwa na turmi yana raguwa da fiye da 8%, kuma lokacin da adadin ya kasance 0.08%, yawan ruwa yana raguwa da fiye da 13.5%. A lokaci guda kuma, tare da tsawo na shekaru, babban adadin ya nuna cewa adadin cellulose ether dole ne a sarrafa shi a cikin wani yanki na musamman, yawan ƙwayar cuta zai haifar da mummunan tasiri akan turmi ruwa. Ruwa da siminti a cikin turmi suna yin tsaftataccen slurry don cike gibin yashi, sannan a naɗe kewaye da yashi don yin aikin mai, ta yadda turmin ya sami ɗan ruwa. Tare da gabatarwar ether cellulose, abun ciki na ruwa mai kyauta a cikin tsarin yana da ƙananan raguwa, kuma an rage girman murfin da ke kan bangon waje na yashi, don haka rage yawan turmi. Saboda buƙatun turmi mai daidaita kai tare da babban ruwa, ya kamata a sarrafa adadin ether cellulose a cikin kewayon da ya dace.

2.2 Riƙe Ruwa

Riƙewar ruwa na turmi shine maƙasudi mai mahimmanci don auna daidaiton abubuwan da ke cikin turmi mai gauraye sabo. Ƙara daidai adadin ether cellulose zai iya inganta riƙewar ruwa na turmi. Domin yin hydration dauki na siminti abu cikakke, madaidaicin adadin ether cellulose zai iya ajiye ruwa a cikin turmi na dogon lokaci don tabbatar da cewa za'a iya aiwatar da aikin hydration na kayan siminti.

Ana iya amfani da ether cellulose a matsayin wakili mai riƙe da ruwa saboda oxygen atoms akan hydroxyl da ether bond suna hade da kwayoyin ruwa don samar da haɗin gwiwar hydrogen, yin ruwa kyauta ya zama ruwan hade. Ana iya gani daga dangantakar dake tsakanin abun ciki na cellulose ether da kuma yawan adadin ruwa na turmi cewa yawan adadin ruwa na turmi yana karuwa tare da karuwar abun ciki na ether cellulose. Tasirin riƙewar ruwa na ether cellulose zai iya hana abin da ake amfani da shi don sha ruwa mai yawa da sauri, da kuma hana ƙawancen ruwa, don haka tabbatar da cewa yanayin slurry yana samar da isasshen ruwa don samar da ruwa na siminti. Har ila yau, akwai binciken da ya nuna cewa ban da adadin cellulose ether, danko (nauyin kwayoyin halitta) yana da tasiri mai yawa akan rikitaccen ruwa na turmi, mafi girman danko, mafi kyawun kiyaye ruwa. Cellulose ether tare da danko na 400 MPa·S ana amfani da shi gabaɗaya don turmi mai daidaita kai, wanda zai iya haɓaka aikin daidaita turmi da haɓaka ƙaƙƙarfan turmi. Lokacin da danko ya wuce 40000 MPa·S, aikin riƙewar ruwa baya inganta sosai, kuma bai dace da turmi mai daidaita kai ba.

A cikin wannan binciken, an ɗauki samfuran turmi tare da ether cellulose da turmi ba tare da ether cellulose ba. Wani ɓangare na samfuran sune samfuran shekarun 3d, kuma ɗayan samfuran samfuran shekaru 3d an daidaita su don 28d, sannan kuma samar da samfuran hydration na siminti a cikin samfuran an gwada ta SEM.

Abubuwan hydration na ciminti a cikin samfurin samfurin turmi a cikin shekaru 3d sun fi waɗanda ke cikin samfurin tare da ether cellulose, kuma a shekarun 28d, samfuran hydration a cikin samfurin tare da ether cellulose sun fi waɗanda ke cikin samfurin blank. Ruwan ruwa na farko yana jinkirta saboda akwai wani fim mai rikitarwa wanda aka kafa ta cellulose ether a saman sassan siminti a farkon mataki. Koyaya, tare da haɓaka shekaru, tsarin hydration yana ci gaba a hankali. A wannan lokacin, riƙewar ruwa na ether cellulose a kan slurry yana sa akwai isasshen ruwa a cikin slurry don saduwa da buƙatun hydration dauki, wanda zai dace da cikakken ci gaba na hydration dauki. Saboda haka, akwai ƙarin samfuran hydration a cikin slurry a mataki na gaba. Dangane da magana, akwai ƙarin ruwa mai kyauta a cikin samfurin mara kyau, wanda zai iya gamsar da ruwan da ake buƙata ta farkon siminti. Duk da haka, tare da ci gaban tsarin hydration, wani ɓangare na ruwan da ke cikin samfurin yana cinyewa ta hanyar farkon hydration dauki, kuma ɗayan ɓangaren ya ɓace ta hanyar evaporation, yana haifar da rashin isasshen ruwa a cikin slurry na baya. Sabili da haka, samfuran hydration na 3d a cikin samfurin blank sun fi yawa. Adadin samfuran hydration ya fi ƙasa da adadin samfuran hydration a cikin samfurin da ke ɗauke da ether cellulose. Sabili da haka, daga yanayin samfurori na hydration, an sake bayyana cewa ƙara yawan adadin cellulose ether zuwa turmi zai iya inganta haɓakar ruwa na slurry.

2.3 Lokacin saita lokaci

Cellulose ether yana da wani tasiri na jinkirtawa akan turmi, tare da karuwar abun ciki na ether cellulose. Lokacin saita turmi sai ya tsawaita. Sakamakon retarding na ether cellulose yana da alaƙa kai tsaye da halayen tsarin sa. Cellulose ether ya dehydrated glucose zobe tsarin, wanda zai iya samar da sukari alli kwayoyin hadaddun kofa tare da alli ions a cikin ciminti hydration bayani, rage taro na alli ions a cikin ciminti hydration lokacin shigar da ruwa, hana samuwar da hazo na Ca (OH) 2 da calcium gishiri. lu'ulu'u, don jinkirta tsarin hydration na siminti. Tasirin ether na cellulose a kan slurry na siminti ya dogara ne akan matakin maye gurbin alkyl kuma yana da ɗan dangantaka da nauyinsa. Karamin matakin maye gurbin alkyl, mafi girman abun ciki na hydroxyl, mafi bayyananniyar sakamako na jinkirtawa. L. Semitz et al. yi imani da cewa cellulose ether kwayoyin aka yafi adsorbed a hydration kayayyakin kamar C — S — H da Ca (OH) 2, kuma da wuya adsorbed a clinker asali ma'adanai. Haɗe tare da bincike na SEM na tsarin hydration na ciminti, an gano cewa ether cellulose yana da wasu sakamako na retarding, kuma mafi girman abun ciki na ether cellulose, mafi mahimmancin sakamako na retarding na hadadden fim din akan farkon hydration na ciminti, sabili da haka, mafi bayyananne sakamako na retarding.

2.4 Ƙarfin sassauƙa da ƙarfin matsawa

Gabaɗaya, ƙarfi yana ɗaya daga cikin mahimman ma'auni na kimanta kayan siminti na tushen siminti yana warkar da tasirin gaurayawan. Baya ga babban aiki mai gudana, turmi mai daidaita kai shima yakamata ya kasance yana da takamaiman ƙarfi da ƙarfi. A cikin wannan binciken, an gwada ƙarfin matsi na kwanaki 7 da 28 da ƙarfin sassauƙa na turmi mara tushe gauraye da ether cellulose.

Tare da haɓakar abun ciki na ether cellulose, turmi compressive ƙarfi da flexural ƙarfi an rage a cikin daban-daban amplitude, abun ciki ne karami, da tasiri a kan ƙarfi ba a bayyane yake, amma tare da abun ciki na fiye da 0.02%, ƙarfin hasara girma girma ya fi bayyane. , sabili da haka, a cikin yin amfani da ether cellulose don inganta haɓakar ruwa na turmi, amma kuma la'akari da canjin ƙarfin.

Abubuwan da ke haifar da turmi matsa lamba da raguwar ƙarfi. Za a iya yin nazari daga abubuwa masu zuwa. Da farko dai, ba a yi amfani da ƙarfin farko da siminti mai ƙarfi a cikin binciken ba. Lokacin da busasshen turmi ya gauraya da ruwa, an fara sanya wasu barbashi na ether roba foda a saman simintin don samar da fim ɗin latex, wanda ya jinkirta hydration na simintin kuma ya rage ƙarfin farkon matrix na turmi. Na biyu, domin a kwaikwayi yanayin aiki na shirya turmi mai daidaita kai a wurin, duk samfuran da ke cikin binciken ba su yi rawar jiki ba a cikin tsarin shirye-shirye da gyare-gyaren, kuma sun dogara da daidaita nauyin kai. Saboda ƙarfin riƙewar ruwa na ether cellulose a cikin turmi, an bar babban adadin pores a cikin matrix bayan taurin turmi. Haɓaka porosity a cikin turmi shima muhimmin dalili ne na raguwar ƙarfin matsawa da jujjuyawar turmi. Bugu da ƙari, bayan ƙara cellulose ether a cikin turmi, abun ciki na polymer mai sassauƙa a cikin pores na turmi yana ƙaruwa. Lokacin da aka danna matrix, polymer mai sassauƙa yana da wahala a taka rawar tallafi mai tsauri, wanda kuma yana shafar ƙarfin aikin matrix zuwa wani ɗan lokaci.

2.5 Ƙarfin haɗin gwiwa

Cellulose ether yana da babban tasiri akan haɗin haɗin ginin turmi kuma ana amfani dashi sosai a cikin bincike da shirye-shiryen turmi mai daidaitawa.

Lokacin da abun ciki na ether cellulose ya kasance tsakanin 0.02% da 0.10%, ƙarfin haɗin turmi yana da kyau a fili, kuma ƙarfin haɗin gwiwa a kwanakin 28 ya fi girma fiye da haka a kwanakin 7. Cellulose ether yana samar da fim ɗin polymer mai rufewa tsakanin simintin hydration barbashi da tsarin tsarin ruwa, wanda ke haɓaka ƙarin ruwa a cikin fim ɗin polymer a waje da simintin siminti, wanda ke daɗaɗawa ga cikakkiyar hydration na ciminti, don haɓaka ƙarfin haɗin gwiwa na manna. bayan taurin. A lokaci guda, adadin da ya dace na ether cellulose yana haɓaka da filastik da sassauci na turmi, yana rage tsattsauran ra'ayi na yankin tsaka-tsakin tsaka-tsaki tsakanin turmi da substrate interface, yana rage damuwa da zamewa tsakanin ma'amala, kuma yana haɓaka tasirin haɗin gwiwa tsakanin turmi da substrate a ciki. wani digiri. Saboda kasancewar cellulose ether a cikin siminti slurry, an kafa wani yanki na musamman na tsaka-tsakin tsaka-tsaki da tsaka-tsakin tsaka-tsakin tsakanin sassan turmi da samfurori na hydration. Wannan tsaka-tsakin tsaka-tsakin yana sa yankin canjin tsaka-tsakin ya zama mafi sassauƙa da ƙarancin ƙarfi, ta yadda turmi ya sami ƙarfin haɗin kai.

3. Kammalawa da Tattaunawa

Cellulose ether na iya inganta riƙewar ruwa na turmi mai daidaita kai. Tare da karuwar adadin ether na cellulose, ana ƙara haɓakar ruwa na turmi a hankali, kuma an rage yawan ruwan turmi da lokacin saita lokaci zuwa wani matsayi. Yawan riƙe ruwa da yawa zai ƙara ƙuri'a na slurry mai tauri, wanda zai iya sa ƙarfin matsawa da sassauƙa na turmi mai taurin ya sami asara bayyananne. A cikin binciken, ƙarfin ya ragu sosai lokacin da adadin ya kasance tsakanin 0.02% da 0.04%, kuma yawancin adadin ether cellulose, mafi mahimmancin sakamako na retarding. Sabili da haka, lokacin amfani da ether cellulose, ya zama dole don la'akari da cikakken la'akari da kayan aikin injiniya na turmi mai daidaita kai, zaɓi mai ma'ana na sashi da tasirin haɗin gwiwa tsakaninsa da sauran kayan sinadarai.

Yin amfani da ether na cellulose na iya rage ƙarfin matsawa da ƙarfin sassauƙa na slurry siminti, da kuma inganta ƙarfin haɗin gwiwa na turmi. Analysis na dalilai na canji na ƙarfi, yafi lalacewa ta hanyar canji na micro kayayyakin da tsarin, a daya hannun, cellulose ether roba foda barbashi da farko adsorbed a saman siminti barbashi, samuwar latex film, jinkirta da hydration na siminti, wanda zai haifar da asarar ƙarfin farko na slurry; A gefe guda, saboda tasirin fim ɗin da ke haifar da tasirin ruwa da tasirin ruwa, yana ba da gudummawa ga cikakkiyar hydration na ciminti da haɓaka ƙarfin haɗin gwiwa. Marubucin ya yi imanin cewa waɗannan canje-canjen ƙarfi guda biyu galibi suna wanzuwa a cikin ƙayyadaddun lokaci, kuma ci gaba da jinkirin wannan iyaka yana iya zama muhimmin batu da ke haifar da girman ƙarfin nau'ikan biyu. Ƙarin zurfin zurfi da bincike na tsari na wannan mahimmancin batu zai zama mai kyau ga tsari mai kyau da kuma nazarin tsarin hydration na siminti a cikin slurry. Yana da taimako don daidaita adadin ether cellulose da lokacin warkewa bisa ga buƙatar kayan aikin turmi, don inganta aikin turmi.