Cellulose ether pamusoro pechimiro che ettringite yekutanga

Mhedzisiro yehydroxyethyl methyl cellulose ether uye methyl cellulose ether pachimiro cheettringite mu slurry yekutanga yesimende yakaongororwa nekushandisa scanning electron microscopy (SEM). Mhedzisiro yacho inoratidza kuti chiyero chehurefu-dhayamita yemakristaro eettringite mu slurry yakagadziriswa yehydroxyethyl methyl cellulose ether yakaderedzwa idiki pane iri mu slurry yakajairika, uye chimiro chekristaro yeettringite chakafanana netsvimbo pfupi. Chiyero chehurefu-dhayamita yemakristaro eettringite mu slurry yakagadziriswa yemethyl cellulose ether yakakura kupfuura iri mu slurry yakajairika, uye chimiro chekristaro yeettringite itsvimbo yesimbi. Makristaro eettringite mu slurry yakajairika yecement ane aspect ratio pakati. Kuburikidza neongororo yataurwa pamusoro apa, zviri pachena kuti musiyano wehuremu hwemamorekuru emhando mbiri dze cellulose ether ndicho chinhu chinonyanya kukanganisa chimiro cheettringite.

Mashoko akakosha:ettringite; Chiyero chedhayamita yehurefu; Methyl cellulose ether; Hydroxyethyl methyl cellulose ether; chimiro

Ettringite, sechigadzirwa chekunyorovesa mvura zvishoma, ine mhedzisiro yakakura pakushanda kwekongiri yesimende, uye yagara iri nzvimbo inonyanya kutsvagurudzwa yezvinhu zvakagadzirwa nesimende. Ettringite imhando yetrisulfide calcium aluminate hydrate, fomura yayo yemakemikari ndeye [Ca3Al (OH)6·12H2O]2·(SO4)3·2H2O, kana kuti inogona kunyorwa se3CaO·Al2O3·3CaSO4·32H2O, inowanzo pfupikiswa seAFt. MuPortland cement system, ettringite inonyanya kuumbwa nekuita kwegypsum ine aluminate kana ferric aluminate minerals, iyo inoita basa rekunonoka hydration uye simba rekutanga kwesimende. Kuumbwa uye morphology ye ettringite zvinokanganiswa nezvinhu zvakawanda zvakaita sekupisa, pH kukosha uye ion concentration. Kare muna 1976, Metha et al. Ndakashandisa scanning electron microscopy kuti ndidzidze hunhu hweAFt, uye ndakaona kuti morphology yezvigadzirwa zve hydration zvakawedzera zvishoma yakanga yakasiyana zvishoma kana nzvimbo yekukura yakanga yakakura zvakakwana uye kana nzvimbo yacho yakanga yakaganhurirwa. Yekutanga yaive yakawanda spherules dzakatetepa dzakaita setsvimbo, nepo yekupedzisira yaive prism pfupi yakaita setsvimbo. Tsvagiridzo yaYang Wenyan yakawana kuti mafomu eAFt akasiyana nenzvimbo dzakasiyana dzekuporesa. Nzvimbo dzakanyorova dzaizononotsa kugadzirwa kweAFt mukongiri yakawedzeredzwa uye kuwedzera mukana wekuzvimba kwekongiri nekutsemuka. Nzvimbo dzakasiyana hadzina kukanganisa chete kuumbwa uye microstructure yeAFt, asiwo kugadzikana kwayo kwevhoriyamu. Chen Huxing et al. vakawana kuti kugadzikana kwenguva refu kweAFt kwakadzikira nekuwedzera kwehuwandu hweC3A. Clark naMonteiro et al. vakaona kuti nekuwedzera kwekumanikidzwa kwezvakatipoteredza, chimiro chekristaro cheAFt chakachinja kubva pakurongeka kuenda pakusagadzikana. Balonis naGlasser vakaongorora shanduko dzehuwandu hweAFm neAFt. Renaudin et al. vakadzidza shanduko dzemaumbirwo eAFt vasati vanyudzwa mumushonga uye mushure mekunyudzwa uye maparamita emaumbirwo eAFt muRaman spectrum. Kunther nevamwe vakadzidza mhedzisiro yekudyidzana pakati peCSH gel calcium-silicon ratio uye sulfate ion paAFt crystallization pressure neNMR. Panguva imwe chete, zvichibva pakushandiswa kweAFt muzvinhu zvakagadzirwa nesimende, Wenk nevamwe vakadzidza kurongeka kweAFt kwechikamu chekongiri kuburikidza ne hard synchrotron radiation X-ray diffraction finishing technology. Kuumbwa kweAFt mu mixed cement uye nzvimbo yekutsvagisa yeettringite kwakaongororwa. Zvichibva pa delayed ettringite reaction, vamwe vadzidzi vakaita tsvakiridzo yakawanda pamusoro pechikonzero cheAFt phase.

Kuwedzera kwehuwandu kunokonzerwa nekuumbwa kweetringite dzimwe nguva kwakanaka, uye kunogona kushanda se "kuwedzera" kwakafanana ne magnesium oxide expansion agent kuchengetedza kugadzikana kwehuwandu hwezvinhu zvakagadzirwa nesimende. Kuwedzerwa kwepolymer emulsion uye redispersible emulsion powder kunochinja hunhu hukuru hwezvinhu zvakagadzirwa nesimende nekuda kwemhedzisiro yazvo yakakosha pa microstructure yezvinhu zvakagadzirwa nesimende. Zvisinei, kusiyana ne redispersible emulsion powder iyo inonyanya kuwedzera hunhu hwe bonding ye hardwood mortar, water-soluble polymer cellulose ether (CE) inopa daka idzva rakasanganiswa kuchengetedza mvura uye thickening effect, nokudaro ichivandudza mashandiro ekushanda. Non-ionic CE inowanzoshandiswa, kusanganisira methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl methyl cellulose (HPMC),hydroxyethyl methyl cellulose (HEMC), nezvimwewo, uye CE ine basa guru mudhaka idzva rakasanganiswa asi inokanganisawo maitiro ekunyorovesa simende. Zvidzidzo zvakaratidza kuti HEMC inochinja huwandu hweAFt inogadzirwa sechigadzirwa chekunyorovesa. Zvisinei, hapana zvidzidzo zvakaenzanisa zvakarongeka mhedzisiro yeCE pachimiro cheAFt chidiki, saka bepa iri rinoongorora musiyano wemhedzisiro yeHEMC neMC pachimiro cheEttringham chidiki pakutanga (kwezuva rimwe) simbi yesimbi kuburikidza nekuongorora nekuenzanisa mifananidzo.

1. Kuedza

1.1 Zvinhu Zvisina Kugadzirwa

P·II 52.5R Portland simende yakagadzirwa neAnhui Conch Cement Co., LTD yakasarudzwa sesimende mukuyedza. Masero maviri e-cellulose ethers ihydroxyethyl methylcellulose (HEMC) uye methylcellulose (methylcellulose, Shanghai Sinopath Group) zvichiteerana. MC); Mvura inosanganiswa imvura yepombi.

1.2 Nzira dzekuyedza

Chiyero chemvura nesimende chemuenzaniso wepaste yesimende chaive 0.4 (chiyero chehuremu hwemvura nesimende), uye huwandu hwe cellulose ether hwaive 1% yehuremu hwesimende. Kugadzirira muenzaniso kwakaitwa zvichienderana neGB1346-2011 “Nzira Yekuyedza Kushandiswa Kwemvura, Kugadzika Nguva uye Kugadzikana kweSimende Yakajairika”. Mushure mekuumba muenzaniso, firimu repurasitiki rakavharirwa pamusoro pechiumbwa kudzivirira kupwa kwemvura pamusoro uye carbonization, uye muenzaniso wakaiswa muimba yekupisa ine tembiricha ye (20±2)℃ uye hunyoro hwe (60±5)%. Mushure mezuva rimwe chete, chiumbwa chakabviswa, uye muenzaniso wakatyoka, ipapo sampuli diki yakatorwa kubva pakati ndokunyikwa muanhydrous ethanol kuti igumise hydration, uye muenzaniso wakatorwa woomeswa usati waedzwa. Sampuli dzakaomeswa dzakanamirwa patafura yemuenzaniso ne conductive double-sided adhesive, uye layer yefirimu yegoridhe yakapfapfaidzwa pamusoro ne Cressington 108auto automatic ion sputtering instrument. Kuyerera kwesimba kwaive 20 mA uye nguva yekuyerera yaive 60 s. FEI QUANTAFEG 650 environmental Scanning electron Microscope (ESEM) yakashandiswa kuona hunhu hweAFt pachikamu chemuenzaniso. Iyo high vacuum secondary electron mode yakashandiswa kuona AFT. Iyo acceleration voltage yaive 15 kV, beam spot dhayamita yaive 3.0 nm, uye daro rekushanda raidzorwa painenge 10 mm.

2. Mhedzisiro nehurukuro

Mifananidzo yeSEM ​​ye ettringite mu slurry yesimbi yakaomeswa neHEMC yakaratidza kuti kukura kweCa (OH)2(CH) yakagadzika kwaive pachena, uye AFt yakaratidza kuunganidzwa kusina kurongeka kweAFt pfupi-senge tsvimbo, uye imwe AFT pfupi-senge tsvimbo yakanga yakafukidzwa nechimiro cheHEMC membrane. Zhang Dongfang nevamwe vake vakawanawo AFt pfupi-senge tsvimbo pavakaona shanduko dze microstructure ye slurry yesimbi yakagadziridzwa neHEMC kuburikidza neESEM. Vaitenda kuti slurry yesimbi yakajairika yaikurumidza kuita mushure mekusangana nemvura, saka AFt crystal yaive diki, uye kuwedzerwa kwehunyoro hwemvura kwakatungamira kuwedzera kuri kuramba kuripo kwehurefu-dhayamita. Zvisinei, HEMC yakawedzera viscosity yemhinduro, yakaderedza kumhanya kwemaion mumushonga uye yakanonoka kusvika kwemvura pamusoro pe clinker particles, saka hurefu-dhayamita yeAFt yakawedzera mutsika isina kusimba uye hunhu hwayo hwakaratidza hupfupi-hwakaita setsvimbo. Zvichienzaniswa neAFt mu slurry yesimbi yesimbi yezera rimwe chete, dzidziso iyi yakasimbiswa zvishoma, asi haishande kutsanangura shanduko dze morphological dzeAFt mu slurry yesimbi yesimbi yakagadziriswa yeMC. Mifananidzo yeSEM ​​yeettridite mu slurry yesimbi yakagadziriswa yeMC yezuva rimwe yakaratidzawo kukura kwakatenderedzwa kweCa(OH)2, mamwe mativi eAFt akafukidzwawo nechimiro chefirimu cheMC, uye AFt yakaratidza hunhu hwe morphological hwekukura kwe cluster. Zvisinei, kana tichienzanisa, AFt crystal mu slurry yesimbi yakagadziriswa yeMC ine chiyero chakakura chehurefu uye chimiro chakatetepa, ichiratidza chimiro chakajairika cheacicular.

Vose HEMC neMC vakanonoka kutanga kwemvura yesimende uye vakawedzera viscosity yemushonga, asi musiyano uripo muhunhu hweAFt morphological hwakakonzerwa nazvo waive uchiri mukuru. Izvi zvinogona kutsanangurwa zvakanyanya kubva pamaonero echimiro chemolecular che cellulose ether uye chimiro cheAFt crystal. Renaudin nevamwe vake vakanyika AFt yakagadzirwa mumushonga wealkali wakagadzirwa kuti vawane "wet AFt", uye vakaibvisa zvishoma ndokuiomesa pamusoro pemushonga weCaCl2 wakazara (35% relative humidity) kuti vawane "dry AFt". Mushure mekuongororwa kwekugadziriswa kwechimiro neRaman spectroscopy uye X-ray powder diffraction, zvakaonekwa kuti pakanga pasina musiyano pakati pezvimiro zviviri izvi, chete nzira yekuumbwa kwemasero ekristaro yakachinja mukuoma, kureva kuti, mukuchinja kwezvakatipoteredza kubva "kunyorova" kuenda "kuoma", makristaro eAFt akaumba masero nenzira yakajairika yekuwedzera zvishoma nezvishoma. Makristaro eAFt nenzira yakajairika yec akava mashoma. Chikamu chikuru chenzvimbo ine mativi matatu chinoumbwa nemutsetse wakajairika, mutsetse wakajairika we b uye mutsetse wakajairika we c izvo zvakamira zvakati twasu. Kana b normals dzakagadziriswa, makristaro e AFt akaungana pamwe chete ne normals, zvichikonzera kukura kwechikamu chemasero mundege ye ab normals. Saka, kana HEMC "ikachengeta" mvura yakawanda kupfuura MC, nzvimbo "yakaoma" inogona kuitika munzvimbo yakasarudzika, zvichikurudzira kuungana kwe lateral uye kukura kwemakristaro e AFt. Patural et al. vakaona kuti kune CE pachayo, kana polymerization yakakwira (kana kuti huremu hwemamorekuru hwakakura), viscosity ye CE inowedzera uye mashandiro ekuchengetedza mvura ari nani. Maumbirwo emamorekuru e HEMCs ne MCS anotsigira iyi fungidziro, ne hydroxyethyl group ine huremu hwemamorekuru hwakakura kupfuura hydrogen group.

Kazhinji, makristaro eAFt anoumbwa uye anonaya chete kana maion akakodzera asvika pakuzara kwakati mugadziriro yemhinduro. Nokudaro, zvinhu zvakaita sehuwandu hweion, tembiricha, pH kukosha uye nzvimbo yekuumbwa mumhinduro yemhinduro zvinogona kukanganisa zvakanyanya chimiro chemakristaro eAFt, uye shanduko mumamiriro ekugadzira ekugadzira zvinogona kushandura chimiro chemakristaro eAFt. Nokudaro, chiyero chemakristaro eAFt mu slurry yesimende yakajairika pakati pezviviri zvinogona kukonzerwa nechinhu chimwe chete chekushandiswa kwemvura mukunyorovesa simende kwekutanga. Zvisinei, mutsauko muhuwandu hwemakristaro eAFt hunokonzerwa neHEMC neMC unofanirwa kuve nekuda kwenzira yavo yekuchengetedza mvura. MaHemc neMCS zvinogadzira "closed loop" yekufambisa mvura mukati me microzone ye slurry yesimende itsva, zvichibvumira "nguva pfupi" umo mvura "iri nyore kupinda uye yakaoma kubuda." Zvisinei, munguva iyi, nharaunda yechikamu chemvura mukati nepedyo ne microzone inochinjwawo. Zvinhu zvakaita sehuwandu hweion, pH, nezvimwewo, Kuchinja kwenzvimbo yekukura kunoratidzwa zvakare muhunhu hwemakristaro eAFt. Iyi "nzira yakavharwa" yekufambisa mvura yakafanana nemaitiro ekuita akatsanangurwa naPourchez et al. HPMC ichiita basa rekuchengetedza mvura.

3. Mhedziso

(1) Kuwedzerwa kwehydroxyethyl methyl cellulose ether (HEMC) uye methyl cellulose ether (MC) kunogona kuchinja zvakanyanya chimiro cheettringite pakutanga (kwezuva rimwe) simende yakajairika.

(2) Kureba nedhayamita yekristaro yeetringite muHEMC modified cement slurry idiki uye ipfupi muchimiro chetsvimbo; Chiyero chehurefu nedhayamita yekristaro yeetringite muMC modified cement slurry yakakura, inova chimiro chetsono. Makristaro eetringite muslurry dzesimende dzakajairika ane aspect ratio pakati pezviviri izvi.

(3) Mhedzisiro yakasiyana ye ether mbiri dze cellulose pachimiro che ettringite inonyanya kukonzerwa nemusiyano uripo pakurema kwemamorekuru.