Tasirin hydroxyethyl cellulose ether akan farkon hydration na CSA siminti

Sakamakonhydroxyethyl cellulose (HEC)da kuma babban ko ƙananan maye gurbin hydroxyethyl methyl cellulose (H HMEC, L HEMC) akan tsarin hydration na farko da samfurori na hydration na sulfoaluminate (CSA) siminti an yi nazarin. Sakamakon ya nuna cewa daban-daban abun ciki na L-HEMC na iya inganta hydration na CSA siminti a cikin 45.0 min ~ 10.0 h. Duk ethers cellulose guda uku sun jinkirta hydration na rushewar ciminti da canjin canji na CSA da farko, sannan kuma inganta hydration a cikin 2.0 ~ 10.0 h. Gabatarwar ƙungiyar methyl ta haɓaka tasirin haɓakar haɓakar hydroxyethyl cellulose ether akan hydration na ciminti CSA, kuma L HEMC yana da tasirin haɓaka mafi ƙarfi; Tasirin ether cellulose tare da madogara daban-daban da digiri na maye gurbin akan samfuran hydration a cikin sa'o'i 12.0 kafin hydration ya bambanta sosai. HEMC yana da tasirin haɓaka mai ƙarfi akan samfuran hydration fiye da HEC. L HEMC da aka gyara CSA siminti slurry yana samar da mafi yawan calcium-vanadite da aluminum danko a 2.0 da 4.0 h na hydration.
Mahimman kalmomi: ciminti sulfoaluminate; Cellulose ether; Wanda zai maye gurbinsa; Digiri na maye gurbin; Tsarin hydration; Samfurin hydration

Sulfoaluminate (CSA) ciminti tare da anhydrous calcium sulfoaluminate (C4A3) da kuma boheme (C2S) kamar yadda babban clinker ma'adinai ne tare da abũbuwan amfãni daga cikin sauri hardening da farkon ƙarfi, anti-daskarewa da anti-permeability, low alkalinity, da ƙananan zafi amfani a cikin samar da tsari, tare da sauki nika na clinker. Ana amfani da shi sosai a gyaran gaggawa, anti-permeability da sauran ayyukan. Cellulose ether (CE) ana amfani da shi sosai wajen gyaran turmi saboda riƙon ruwa da kauri. CSA siminti hydration dauki yana da rikitarwa, lokacin shigarwa yana da ɗan gajeren lokaci, lokacin hanzari yana da matakai da yawa, kuma hydration ɗin sa yana da sauƙi ga tasirin admixture da zafin jiki. Zhang et al. gano cewa HEMC na iya tsawaita lokacin shigar da ruwa na simintin CSA kuma ya sanya babban kololuwar sakin zafi mai zafi. Sun Zhenping et al. gano cewa tasirin sha ruwa na HEMC ya shafi farkon hydration na siminti slurry. Wu Kai et al. sun yi imanin cewa raunin da aka samu na HEMC a saman simintin CSA bai isa ya shafi yawan sakin zafi na ciminti ba. Sakamakon bincike kan tasirin HEMC akan ruwa na siminti na CSA ba daidai ba ne, wanda zai iya haifar da abubuwa daban-daban na clinker siminti da aka yi amfani da su. Wan et al. gano cewa riƙewar ruwa na HEMC ya fi na hydroxyethyl cellulose (HEC), da kuma ƙarfin danko da tashin hankali na rami bayani na HEMC-gyara CSA ciminti slurry tare da babban canji digiri sun fi girma. Li Jian et al. ya lura da canje-canjen zafin jiki na farko na HEMC-gyara CSA siminti a ƙarƙashin tsayayyen ruwa kuma ya gano cewa tasirin HEMC tare da digiri daban-daban na maye gurbin ya bambanta.
Koyaya, binciken kwatancen akan tasirin CE tare da madogara daban-daban da digiri na canji akan farkon hydration na siminti CSA bai wadatar ba. A cikin wannan takarda, an yi nazarin tasirin hydroxyethyl cellulose ether tare da abun ciki daban-daban, ƙungiyoyi masu maye gurbin da digiri na maye gurbin a farkon hydration na ciminti CSA. Dokar sakin zafi mai zafi na 12h da aka gyara simintin CSA tare da hydroxyethyl cellulose ether an yi nazari sosai, kuma an yi nazarin samfuran hydration da ƙima.

1. Gwaji
1.1 Raw Materials
Siminti shine maki 42.5 mai saurin taurare siminti na CSA, lokacin saitin farko da na ƙarshe shine 28 min da 50 min, bi da bi. Abubuwan da ke tattare da sinadarai da abun da ke ciki na ma'adinai (masu yawan juzu'i, adadin da ruwa-ciminti rabo da aka ambata a cikin wannan takarda sune juzu'i ko rabo mai yawa) mai gyara CE ya haɗa da 3 hydroxyethyl cellulose ethers tare da danko mai kama: Hydroxyethyl cellulose (HEC), babban mataki na maye gurbin hydroxyethyl methyl cellulose (H HEMC), ƙananan digiri na maye gurbin hydroxyethyl methyl fibrin (L HEMC), danko na 32, 37, 36 Pa·s, digiri na maye gurbin 2.5, 1.9, 1.6 ruwan hadawa don ruwa mai lalata.
1.2 Mix rabo
Kafaffen rabon ruwa-ciminti na 0.54, abun ciki na L HEMC (ana ƙididdige abubuwan da ke cikin wannan labarin ta ingancin laka na ruwa) wL = 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, HEC da H HEMC abun ciki na 0.5%. A cikin wannan takarda: L HEMC 0.1 wL = 0.1% L HEMC canza simintin CSA, da sauransu; CSA siminti ne na CSA tsantsa; HEC ciminti CSA gyara, L HEMC ciminti CSA gyara, H HEMC da aka gyara CSA ciminti ana kiransa HCSA, LHCSA, HHCSA.
1.3 Hanyar gwaji
An yi amfani da micrometer isothermal na tashar tashoshi takwas tare da ma'auni na 600 mW don gwada zafi na hydration. Kafin gwajin, an daidaita kayan aiki a (20± 2) ℃ da dangi zafi RH = (60± 5)% don 6.0 ~ 8.0 h. CSA siminti, CE da hadawa ruwa an gauraye bisa ga mahaɗin rabo da lantarki hadawa da aka yi na 1min a gudun 600 r/min. Nan da nan auna (10.0± 0.1) g slurry a cikin ampoule, saka ampoule a cikin kayan aiki kuma fara gwajin lokaci. Yawan zafin jiki na hydration ya kasance 20 ℃, kuma an rubuta bayanan kowane minti 1, kuma gwajin ya kasance har zuwa 12.0h.
Binciken Thermogravimetric (TG): An shirya slurry na siminti bisa ga TS EN ISO 9597-2008 Siminti - Hanyoyin gwaji - Ƙayyade lokacin saita lokaci da sauti. A cakuda ciminti slurry aka saka a cikin gwajin mold na 20 mm × 20 mm × 20 mm, da kuma bayan wucin gadi vibration na 10 sau, an sanya shi a karkashin (20 ± 2) ℃ da RH = (60 ± 5) % for curing. An fitar da samfuran a cikin shekarun t=2.0, 4.0 da 12.0 h, bi da bi. Bayan cire samfurin samfurin (≥1 mm), an karya shi cikin ƙananan ƙananan kuma an jiƙa shi a cikin barasa isopropyl. An maye gurbin barasa na isopropyl kowane 1d na tsawon kwanaki 7 a jere don tabbatar da cikakken dakatarwar amsawar hydration, kuma an bushe shi a 40 ℃ zuwa nauyi akai-akai. Yi nauyi (75 ± 2) MG samfurori a cikin crucible, zafi da samfurori daga 30 ℃ zuwa 1000 ℃ a zazzabi kudi na 20 ℃ / min a cikin nitrogen yanayi karkashin adiabatic yanayin. The thermal bazuwar na CSA ciminti hydration kayayyakin yafi faruwa a 50 ~ 550 ℃, da kuma abun ciki na chemically daure ruwa za a iya samu ta hanyar kirga da taro asarar kudi na samfurori a cikin wannan kewayon. AFt rasa 20 crystalline ruwa da AH3 rasa 3 crystalline ruwa a lokacin da thermal bazuwar a 50-180 ℃. Ana iya ƙididdige abubuwan da ke cikin kowane samfurin hydration bisa ga lanƙwan TG.

2. Sakamako da tattaunawa
2.1 Nazarin tsarin hydration
2.1.1 Tasirin abun ciki na CE akan tsarin ruwa
Bisa ga hydration da exothermic masu lankwasa na daban-daban abun ciki L HEMC modified CSA ciminti slurry, akwai 4 exothermic kololuwa a kan hydration da exothermic masu lankwasa na CSA cement slurry (wL=0%). Ana iya raba tsarin hydration zuwa matakin rushewa (0 ~ 15.0min), matakin canji (15.0 ~ 45.0min) da matakin hanzari (45.0min) ~ 54.0min), matakin ragewa (54.0min ~ 2.0h), matakin daidaitawa mai ƙarfi 2.0 ~ 4.0h), mataki na sake haɓakawa (4.0 ~ 5.0h), mataki na sakewa (5.0 ~ 10.0h) da kuma matakan daidaitawa (10.0h ~). A cikin 15.0min kafin hydration, ma'adinan ciminti ya narkar da sauri, kuma na farko da na biyu hydration exothermic kololuwa a cikin wannan mataki da 15.0-45.0 min yayi daidai da samuwar metastable lokaci AFt da canji zuwa monosulfide calcium aluminate hydrate (AFm), bi da bi. Na uku exothermal kololuwa a 54.0min na hydration da aka yi amfani da su raba hydration hanzari da deceleration matakai, da kuma tsara rates na AFt da AH3 dauki wannan a matsayin inflection batu, daga boom zuwa raguwa, sa'an nan kuma shiga cikin tsauri ma'auni mataki na 2.0 h. . Lokacin da hydration ya kasance 4.0h, hydration ya sake shiga mataki na hanzari, C4A3 shine saurin rushewa da samar da samfurori na hydration, kuma a 5.0h, kololuwar zafi na hydration exothermic ya bayyana, sa'an nan kuma sake shiga mataki na raguwa. Ruwan ruwa ya daidaita bayan kusan 10.0h.
Tasirin abun ciki na L HEMC akan rushewar siminti na CSAkuma matakin juyi ya bambanta: lokacin da abun ciki na L HEMC yayi ƙasa, L HEMC gyaggyara CSA siminti manna na biyu hydration zafi saki ganiya ya bayyana kadan a baya, zafi saki kudi da zafi saki ganiya darajar ne muhimmanci mafi girma fiye da tsarki CSA siminti manna; Tare da haɓakar abun ciki na L HEMC, ƙimar sakin zafi na L HEMC da aka gyaggyara CSA siminti slurry ya ragu a hankali, kuma ƙasa da zallar siminti na CSA mai tsafta. Yawan kololuwar kololuwa a cikin hydration exothermic curve na L HEMC 0.1 daidai yake da na siminti na CSA mai tsafta, amma 3rd da 4th hydration exothermic kololuwa an haɓaka zuwa 42.0min da 2.3h, bi da bi, kuma idan aka kwatanta da 33.5 da 9.0 mW/g na tsantsar manna siminti na CSA, kololuwar su sun karu zuwa 36.9 da 10.5mW/g, bi da bi. Wannan yana nuna cewa 0.1% L HEMC yana haɓaka da haɓaka hydration na L HEMC da aka gyara CSA siminti a daidai matakin. Kuma L HEMC abun ciki shine 0.2% ~ 0.5%, L HEMC gyaggyarawa CSA ciminti hanzari da ragewa mataki sannu a hankali hade, wato, na huɗu exothermic ganiya a gaba da kuma hade tare da uku exothermic ganiya, tsakiyar tsauri balance mataki ba ya bayyana. , L HEMC akan CSA ciment hydration haɓaka tasirin ya fi mahimmanci.
L HEMC ya inganta hydration na simintin CSA a cikin 45.0 min ~ 10.0 h. A cikin 45.0min ~ 5.0h, 0.1% L HEMC yana da ɗan tasiri akan hydration na CSA siminti, amma lokacin da abun ciki na L HEMC ya karu zuwa 0.2% ~ 0.5%, sakamakon ba shi da mahimmanci. Wannan ya bambanta da tasirin CE akan hydration na simintin Portland. Nazarin wallafe-wallafen sun nuna cewa CE mai ɗauke da adadi mai yawa na ƙungiyoyin hydroxyl a cikin kwayoyin za a sanya su a saman simintin siminti da samfuran hydration saboda hulɗar acid-base, don haka jinkirta farkon hydration na simintin Portland, kuma mafi ƙarfi adsorption, mafi bayyananne jinkiri. Duk da haka, an gano a cikin wallafe-wallafen cewa ƙarfin adsorption na CE akan AFt ya kasance mai rauni fiye da na calcium silicate hydrate (C‑ H) gel, Ca (OH) 2 da calcium aluminate hydrate surface, yayin da karfin adsorption na HEMC akan simintin CSA shima ya yi rauni fiye da na simintin Portland. Bugu da kari, oxygen atom a kan kwayoyin CE zai iya gyara ruwan kyauta a cikin nau'in haɗin hydrogen a matsayin ruwa mai ɗorewa, canza yanayin ruwa mai ƙura a cikin slurry na siminti, sannan kuma ya shafi hydration na siminti. Koyaya, raunin adsorption da shayarwar ruwa na CE a hankali zai raunana tare da tsawaita lokacin hydration. Bayan wani ɗan lokaci, za a saki ruwan da aka ɗora kuma a ƙara mayar da martani tare da barbashi na siminti mara ruwa. Hakanan, tasirin haɓakar CE na iya samar da dogon sarari don samfuran hydration. Wannan na iya zama dalilin da ya sa L HEMC ke inganta hydration ciminti na CSA bayan 45.0 min hydration.
2.1.2 Tasirin maye gurbin CE da digirinsa akan tsarin ruwa
Ana iya ganin shi daga madaidaitan sakin zafi na hydration na slurries CSA guda uku da aka gyara. Idan aka kwatanta da L HEMC, madaidaicin adadin sakin zafi na HEC da H HEMC da aka gyara CSA slurries suma suna da kololuwar sakin zafi mai zafi guda huɗu. Dukkanin CE guda uku sun jinkirta sakamako akan rushewar da matakan juyawa na CSA siminti hydration, kuma HEC da H HEMC suna da tasirin jinkiri mai ƙarfi, jinkirta fitowar matakan haɓakar hydration. Bugu da kari na HEC da H-HEMC dan kadan jinkirta 3rd hydration exothermic kololuwa, muhimmanci inganta 4th hydration exothermic ganiya, da kuma ƙara kololuwa na 4th hydration exothermic ganiya. A ƙarshe, hydration zafi saki na uku CE modified CSA slurries ne mafi girma fiye da na tsantsar CSA slurries a cikin hydration lokaci na 2.0 ~ 10.0 h, yana nuna cewa uku CE ta duk inganta hydration na CSA siminti a wannan mataki. A cikin hydration lokaci na 2.0 ~ 5.0 h, da hydration zafi saki na L HEMC modified CSA ciminti ne mafi girma, da kuma H HEMC da HEC ne na biyu, yana nuna cewa inganta sakamako na low maye HEMC a kan hydration na CSA ciminti ya fi karfi. . Sakamakon catalytic na HEMC ya fi ƙarfin HEC, yana nuna cewa ƙaddamar da ƙungiyar methyl ya inganta tasirin tasirin CE akan hydration na CSA siminti. Tsarin sinadarai na CE yana da babban tasiri akan tallan sa a saman simintin siminti, musamman ma matakin maye gurbinsa da nau'in maye.
Matsala mai tsauri na CE ya bambanta tare da maye gurbin daban-daban. HEC yana da hydroxyethyl kawai a cikin sarkar gefe, wanda ya fi ƙasa da HEMC mai ɗauke da ƙungiyar methyl. Sabili da haka, HEC yana da tasirin adsorption mafi ƙarfi akan ƙwayoyin siminti na CSA kuma mafi girman tasiri akan hulɗar hulɗar tsakanin simintin siminti da ruwa, don haka yana da tasirin jinkiri mafi bayyane akan kololuwar hydration exothermic na uku. Ruwan ruwa na HEMC tare da babban canji yana da ƙarfi sosai fiye da na HEMC tare da ƙaramin canji. A sakamakon haka, ruwan kyauta da ke cikin halayen hydration tsakanin sifofin flocculated ya ragu, wanda ke da tasiri mai girma akan farkon hydration na ciminti CSA da aka gyara. Saboda wannan, kololuwar hydrothermal na uku ya jinkirta. Ƙananan maye gurbin HEMCs suna da raunin sha ruwa da ɗan gajeren lokacin aiki, wanda ke haifar da farkon sakin ruwa mai ban sha'awa da kuma ƙara yawan hydration na adadi mai yawa na siminti maras ruwa. Rarraunawar adsorption da shayarwar ruwa suna da tasirin jinkiri daban-daban akan rushewar hydration da matakin canzawa na simintin CSA, wanda ke haifar da bambanci a cikin haɓakar hydration na ciminti a cikin matakin ƙarshe na CE.
2.2 Binciken samfuran hydration
2.2.1 Tasirin abun ciki na CE akan samfuran ruwa
Canza madaidaicin TG DTG na CSA ruwa slurry ta daban-daban abun ciki na L HEMC; Abubuwan da ke cikin ruwa da aka ɗaure da sinadarai ww da samfuran ruwa AFt da AH3 wAFt da wAH3 an ƙididdige su bisa ga madaidaicin TG. Sakamakon ƙididdigewa ya nuna cewa maƙallan DTG na tsantsa siminti na CSA sun nuna kololuwa uku a 50 ~ 180 ℃, 230 ~ 300 ℃ da 642 ~ 975 ℃. Daidai da AFt, AH3 da lalata dolomite, bi da bi. A hydration 2.0 h, TG masu lankwasa na L HEMC modified CSA slurry sun bambanta. Lokacin da hydration dauki ya kai 12.0 h, babu wani gagarumin bambanci a cikin masu lankwasa. A 2.0h hydration, da sinadaran dauri ruwa abun ciki na wL = 0%, 0.1%, 0.5% L HEMC modified CSA ciminti manna shi ne 14.9%, 16.2%, 17.0%, da AFt abun ciki shine 32.8%, 35.2%, 36.7%, bi da bi. Abun da ke cikin AH3 ya kasance 3.1%, 3.5% da 3.7%, bi da bi, yana nuna cewa haɗakarwar L HEMC ya inganta matakin hydration na ciminti slurry hydration na 2.0 h, da haɓaka samar da samfuran hydration AFt da AH3, wato, haɓakawa. hydration na CSA siminti. Wannan na iya zama saboda HEMC ya ƙunshi duka hydrophobic kungiyar methyl da hydrophilic kungiyar hydroxyethyl, wanda yana da high surface aiki da kuma iya muhimmanci rage surface tashin hankali na ruwa lokaci a siminti slurry. A lokaci guda, yana da tasirin haɓaka iska don sauƙaƙe samar da samfuran hydration na siminti. A 12.0 h na hydration, abubuwan AFt da AH3 a cikin L HEMC gyare-gyaren CSA siminti slurry da tsantsar ciminti na CSA ba su da wani muhimmin bambanci.
2.2.2 Tasirin masu maye gurbin CE da matakan maye gurbinsu akan samfuran ruwa
Tsarin TG DTG na CSA siminti slurry wanda aka gyara ta CE guda uku (abun ciki na CE shine 0.5%); Sakamakon lissafin daidaitattun ww, wAFt da wAH3 sune kamar haka: a hydration 2.0 da 4.0 h, TG curves na daban-daban siminti slurries sun bambanta sosai. Lokacin da hydration ya kai 12.0 h, TG curves na daban-daban siminti slurries ba su da wani gagarumin bambanci. A 2.0 h hydration, da chemically daure abun ciki na ruwa mai tsabta CSA siminti slurry da HEC, L HEMC, H HEMC gyaggyarawa CSA siminti slurry ne 14.9%, 15.2%, 17.0%, 14.1%, bi da bi. A sa'o'i 4.0 na ruwa, madaidaicin TG na tsantsar siminti na CSA ya ragu kaɗan. Matsayin hydration na slurries na CSA guda uku da aka gyara na CE ya fi na tsantsar slurries na CSA, kuma abun ciki na ruwan da aka ɗaure da sinadarai na HEMC da aka gyara CSA slurries ya fi na HEC gyara CSA slurries. L HEMC gyare-gyaren CSA siminti slurry sinadaran daura abun ciki na ruwa shine mafi girma. A ƙarshe, CE tare da madogara daban-daban da digiri na maye yana da bambance-bambance masu mahimmanci akan samfuran farko na hydration na siminti CSA, kuma L-HEMC yana da babban tasirin haɓakawa akan samuwar samfuran hydration. A lokacin hydration na 12.0 h, babu wani bambanci mai mahimmanci tsakanin yawan asarar yawan adadin CE guda uku da aka gyara na CSA siminti slurps da na siminti na CSA mai tsabta, wanda ya yi daidai da sakamakon sakin zafi, yana nuna cewa CE kawai ya shafi hydration na CSA siminti a cikin sa'o'i 12.0.
Hakanan ana iya ganin cewa AFt da AH3 halayyar kololuwar ƙarfi na L HEMC da aka gyara CSA slurry sune mafi girma a hydration 2.0 da 4.0 h. AFt abun ciki na tsantsar CSA slurry da HEC, L HEMC, H HEMC slurry CSA sun kasance 32.8%, 33.3%, 36.7% da 31.0%, bi da bi, a 2.0h hydration. AH3 abun ciki ya kasance 3.1%, 3.0%, 3.6% da 2.7%, bi da bi. A 4.0 h na hydration, abun ciki na AFt shine 34.9%, 37.1%, 41.5% da 39.4%, kuma AH3 abun ciki shine 3.3%, 3.5%, 4.1% da 3.6%, bi da bi. Ana iya ganin cewa L HEMC yana da tasiri mai ƙarfi na haɓakawa akan samuwar samfuran ruwa na simintin CSA, kuma tasirin haɓakar HEMC ya fi na HEC ƙarfi. Idan aka kwatanta da L-HEMC, H-HEMC ya inganta danko mai ƙarfi na maganin pore mafi mahimmanci, don haka yana shafar jigilar ruwa, yana haifar da raguwa a cikin ƙimar shigar da slurry, kuma yana rinjayar samar da samfurin hydration a wannan lokacin. Idan aka kwatanta da HEMCs, tasirin haɗin gwiwar hydrogen a cikin kwayoyin HEC ya fi bayyane, kuma tasirin shayar da ruwa ya fi karfi kuma yana dawwama. A wannan lokacin, tasirin shayarwar ruwa na HEMCs masu girma da ƙananan musanya HEMC ba a bayyane yake ba. Bugu da kari, CE tana samar da “rufe madauki” na jigilar ruwa a cikin karamin yanki a cikin slurry na siminti, kuma ruwan da CE ta saki sannu a hankali zai iya ƙara amsa kai tsaye tare da sassan siminti da ke kewaye. A 12.0 h na hydration, tasirin CE akan samar da AFt da AH3 na CSA siminti slurry ba su da mahimmanci.

3. Kammalawa
(1) Rashin ruwa na sulfoaluminate (CSA) sludge a cikin 45.0 min ~ 10.0 h ana iya inganta shi tare da nau'i daban-daban na ƙananan hydroxyethyl methyl fibrin (L HEMC).
(2) Hydroxyethyl cellulose (HEC), babban maye gurbin hydroxyethyl methyl cellulose (H HEMC), L HEMC HEMC, wadannan uku hydroxyethyl cellulose ether (CE) sun jinkirta rushewa da kuma juyi mataki na CSA ciminti hydration, da kuma inganta hydration na 2.0 ~ 10.0 h.
(3) Gabatarwar methyl a cikin hydroxyethyl CE na iya haɓaka tasirin haɓakawa akan hydration na ciminti na CSA a cikin 2.0 ~ 5.0 h, da tasirin haɓakar L HEMC akan hydration na ciminti CSA ya fi ƙarfin H HEMC.
(4) Lokacin da abun ciki na CE ya kasance 0.5%, adadin AFt da AH3 da aka samar ta hanyar L HEMC da aka gyara CSA slurry a hydration 2.0 da 4.0 h shine mafi girma, kuma tasirin inganta hydration shine mafi mahimmanci; H HEMC da HEC da aka gyara CSA slurries sun samar da mafi girma AFt da AH3 abun ciki fiye da tsaftataccen CSA slurries kawai a 4.0 h na hydration. A 12.0 h na hydration, tasirin 3 CE akan samfuran hydration na simintin CSA ba su da mahimmanci.