Ka hopena o ka cellulose ether i ka wela o ka hydration o nā sima ʻokoʻa a me ka ʻele hoʻokahi

ua hoʻohālikelike ʻia nā hopena o ka cellulose ether ma ka wela hydration o Portland cement, sulfoaluminate cement, tricalcium silicate a me tricalcium aluminate i 72h i hoʻohālikelike ʻia e ka isothermal calorimetry test. Hōʻike nā hopena e hiki i ka cellulose ether ke hoʻemi nui i ka hydration a me ka hoʻokuʻu wela o Portland cement a me tricalcium silicate, a ʻoi aku ka nui o ka hopena o ka hoʻemi ʻana i ka hydration a me ka hoʻokuʻu wela o ka tricalcium silicate. ʻO ka hopena o ka cellulose ether i ka hoʻohaʻahaʻaʻana i ka hoʻokuʻuʻana o ka wela o ka hydration o ka sulfoaluminate cement he nāwaliwali loa, akā he hopena nāwaliwali ia i ka hoʻomaikaʻiʻana i ka hoʻokuʻu wela o ka hydration o tricalcium aluminate. E hoʻopili ʻia ka cellulose ether e kekahi mau huahana hydration, no laila e hoʻopaneʻe i ka crystallization o nā huahana hydration, a laila e hoʻopili i ka hydration wela hoʻokuʻu ʻana o ka sima a me ka ʻai hoʻokahi.

Hua'ōlelo nui:cellulose ether; Sima; ʻOka hoʻokahi; Ka wela o ka wai; adsorption

1. Hoʻolauna

ʻO ka cellulose ether kahi mea hoʻopaʻa mānoanoa nui a me ka mea hoʻopaʻa wai i loko o ka palaki maloʻo i hui pū ʻia, ka paʻa paʻa ponoʻī a me nā mea hana sima hou. Eia nō naʻe, e hoʻopaneʻe pū ka cellulose ether i ka hydration cement, kahi mea e hoʻomaikaʻi ai i ka manawa hana o nā mea hana sima, hoʻomaikaʻi i ka paʻa ʻana o ka mortar a me ka nalowale o ka manawa slump, akā hiki ke lohi i ka holomua o ke kūkulu ʻana. ʻO ka mea kūikawā, e loaʻa iā ia nā hopena ʻino i ka mortar a me ke kaila i hoʻohana ʻia i nā kūlana kaiapuni haʻahaʻa. No laila, he mea nui e hoʻomaopopo i ke kānāwai o cellulose ether ma nā kinetics hydration cement.

Ua aʻo pū ʻo OU lāua ʻo Pourchez i nā hopena o nā ʻāpana molekala e like me ke kaumaha molekala o cellulose ether, ke ʻano o ka mea pani a i ʻole ke degere o ka hoʻololi ʻana i nā kinetics hydration cement, a ua huki i nā hopena koʻikoʻi he nui: ʻO ka hiki o ka hydroxyethyl cellulose ether (HEC) ke hoʻopaneʻe i ka hydration o ʻOi aku ka ikaika o ka sima ma mua o ka methyl cellulose ether (HPMC), hydroxymethyl ethyl cellulose ether (HEMC) a me ka methyl cellulose ether (MC). I loko o ka cellulose ether i loaʻa ka methyl, ʻo ka haʻahaʻa o ka methyl content, ʻoi aku ka ikaika o ka hiki ke hoʻopaneʻe i ka hydration o ka sima; ʻO ka haʻahaʻa o ke kaumaha o ka cellulose ether, ʻoi aku ka ikaika o ka hiki ke hoʻopaneʻe i ka hydration o ka sima. Hāʻawi kēia mau hopena i kumu ʻepekema no ke koho pololei ʻana i ka cellulose ether.

No nā ʻāpana like ʻole o ka sima, ʻo ka hopena o ka cellulose ether ma nā kinetics hydration cement he pilikia nui hoʻi i nā noi ʻenehana. Eia naʻe, ʻaʻohe noiʻi e pili ana i kēia ʻano. I loko o kēia pepa, ua aʻo ʻia ka mana o ka cellulose ether ma ka hydration kinetics o Portland cement maʻamau, C3S (tricalcium silicate), C3A (tricalcium aluminate) a me sulfoaluminate cement (SAC) i aʻo ʻia ma o ka isothermal calorimetry test, i mea e hoʻomaopopo hou ai i ka pilina a me ka hana kūloko ma waena o cellulose ether a me nā huahana hydration cement. Hāʻawi ia i kumu ʻepekema hou aʻe no ka hoʻohana pono ʻana o ka cellulose ether i nā mea hana sima a hāʻawi pū i kumu noiʻi no ka launa pū ʻana ma waena o nā mea hoʻohui ʻē aʻe a me nā huahana hydration sima.

2. Hoao

2.1 Mea Maka

(1) sima Portland maʻamau (P·0). Hana ʻia e Wuhan Huaxin Cement Co., LTD., ʻo ka kikoʻī ʻo P · 042.5 (GB 175-2007), i hoʻoholo ʻia e ka hawewe dispersion-type X-ray fluorescence spectrometer (AXIOS advanced, PANalytical Co., LTD.). Wahi a ka loiloi o JADE 5.0 lako polokalamu, ma kahi o nā minela clinker sima C3S, C2s, C3A, C4AF a me ka gypsum, ʻo nā mea waiwai sima pū kekahi me ka calcium carbonate.

(2) sulfoaluminate cement (SAC). ʻO ka sima sulfoaluminate wikiwiki wikiwiki i hana ʻia e Zhengzhou Wang Lou Cement Industry Co., Ltd. ʻo R.Star 42.5 (GB 20472-2006). ʻO kāna mau pūʻulu nui he calcium sulfoaluminate a me dicalcium silicate.

(3) tricalcium silicate (C3S). E kaomi iā Ca(OH)2, SiO2, Co2O3 a me H2O ma 3:1:0.08: Ua hui like ʻia kahi lakio nui o 10 a kaomi ʻia ma lalo o ke kaomi mau o 60MPa e hana i ka billet ʻōmaʻomaʻo cylindrical. Ka billet ua calcined ma 1400 ℃ no 1.5 ~ 2 h i loko o ka silicon-molybdenum koʻokoʻo kiʻekiʻe wela uila umu ahi, a laila, hoʻoneʻe i loko o ka microwave umu no ka microwave hou wela no 40min. Ma hope o ka lawe ʻana i ka billet, ua maʻalili koke ʻia a haki pinepine ʻia a calcined a hiki i ka liʻiliʻi o ka ʻike o ka CaO manuahi i ka huahana i hoʻopau ʻia ma lalo o 1.0%

(4) tricalcium aluminate (c3A). CaO a me A12O3 ua hui like like, calcined ma 1450 ℃ no 4 h i loko o ka silicon-molybdenum kookoo uila umu ahi, lepo i pauka, a pinepine calcined a hiki i ka maʻiʻo o free CaO i emi ma mua o 1.0%, a me na piko o C12A7 a me CA. mālama ʻole ʻia.

(5) cellulose etera. Ua hoʻohālikelike ka hana mua i nā hopena o nā ʻano cellulose ethers he 16 i ka hydration a me ka hoʻokuʻu wela o ka sima Portland maʻamau, a ua ʻike ʻia he ʻokoʻa koʻikoʻi nā ʻano ʻano cellulose ethers i ka hydration a me ke kānāwai hoʻokuʻu wela o ka sima, a ua kālailai ʻia ke ʻano o loko. o keia okoa nui. Wahi a nā hopena o ka noiʻi mua ʻana, ua koho ʻia ʻekolu ʻano cellulose ether i loaʻa ka hopena hoʻopaneʻe ma luna o ka sima Portland maʻamau. ʻO kēia ka hydroxyethyl cellulose ether (HEC), hydroxypropyl methyl cellulose ether (HPMC), a me ka hydroxyethyl methyl cellulose ether (HEMC). Ua ana ʻia ka viscosity o cellulose ether e ka rotary viscometer me ka hoʻāʻo ʻana o 2%, kahi mahana o 20 ℃ a me ka wikiwiki o ka huli ʻana o 12 r / min. Ua ana ʻia ka viscosity o cellulose ether e ka rotary viscometer me ka hoʻāʻo ʻana o 2%, kahi mahana o 20 ℃ a me ka wikiwiki o ka huli ʻana o 12 r / min. Hāʻawi ʻia ka molar substitution degere o cellulose ether e ka mea hana.

(6) Wai. E hoʻohana i ka wai distilled lua.

2.2 Hana ho'āʻo

Ka wela o ka wai. Ua ʻae ʻia ka TAM Air 8-channel isothermal calorimeter i hana ʻia e TA Instrument Company. Mālama ʻia nā mea maka a pau i ka wela mau e hoʻāʻo ai i ka mahana (e like me (20± 0.5) ℃) ma mua o ka hoʻokolohua. ʻO ka mea mua, ua hoʻohui ʻia he 3 g cement a me 18 mg cellulose etera pauka i loko o ka calorimeter (ka lākiō nui o ka cellulose ether i ka mea cemellative he 0.6%). Ma hope o ka hui pū ʻana, ua hoʻohui ʻia ka wai hui ʻia (ka wai hoʻoheheʻe lua) e like me ka ratio wai-cement i kuhikuhi ʻia a hoʻoulu ʻia. A laila, hoʻokomo koke ʻia i loko o ka calorimeter no ka hoʻāʻo ʻana. ʻO ka lākiō hoʻopaʻa wai o c3A he 1.1, a ʻo ka ratio hoʻopaʻa wai o nā mea hoʻoheheʻe ʻekolu he 0.45.

3. Nā hopena a me ke kūkākūkā

3.1 Nā hopena hoʻāʻo

ʻO nā hopena o HEC, HPMC a me HEMC i ka hoʻokuʻu ʻana i ka wela hydration a me ka huina hoʻokuʻu wela o ka sima Portland maʻamau, C3S a me C3A i loko o 72 mau hola, a me nā hopena o HEC i ka hydration heat release rate a cumulative heat release rate of sulfoaluminate cement i loko o 72 mau hola, ʻo HEC ka cellulose ether me ka hopena lohi loa i ka hydration o nā sima ʻē aʻe a me ka ʻaila hoʻokahi. ʻO ka hoʻohui ʻana i nā hopena ʻelua, hiki ke ʻike ʻia me ka hoʻololi ʻana o ka haku mele cementitious, cellulose ether nā hopena like ʻole i ka hydration heat release rate a me ka hoʻokuʻu ʻana i ka wela cumulative. Hiki i ka cellulose ether i koho ʻia ke hoʻemi nui i ka hydration a me ka hoʻokuʻu wela o ka sima Portland maʻamau a me C, S, e hoʻolōʻihi i ka manawa induction manawa, hoʻopaneʻe i ke ʻano o ka hydration a me ka wela hoʻokuʻu wela, ma waena o ka cellulose ether i C, S hydration a ʻoi aku ka ʻike o ka lohi hoʻokuʻu wela ma mua o ka hydration sima Portland maʻamau a me ka lohi hoʻokuʻu wela; Hiki i ka cellulose ether ke hoʻopaneʻe i ka hoʻokuʻu ʻana o ka wela o ka sulfoaluminate cement hydration, akā nāwaliwali loa ka hiki ke hoʻopaneʻe, a ʻo ka mea nui e hoʻopaneʻe i ka hydration ma hope o 2 h; No ka hoʻokuʻu ʻana i ka wela o ka C3A hydration, cellulose ether i nāwaliwali ka wikiwiki wikiwiki.

3.2 Ka nānā 'ana a me ke kūkākūkā

ʻO ke ʻano o ka cellulosic ether e hoʻopaneʻe i ka hydration cement. Silva et al. Ua manaʻo ʻia ua hoʻonui ka cellulosic ether i ka viscosity o ka solution pore a keʻakeʻa i ka wikiwiki o ka neʻe ʻana o ka ionic, no laila ke hoʻopaneʻe nei i ka hydration cement. Eia naʻe, nui nā palapala i kānalua i kēia manaʻo, no ka mea, ua ʻike kā lākou mau hoʻokolohua he ʻoi aku ka ikaika o ka cellulose ethers me ka viscosity haʻahaʻa e hoʻopaneʻe i ka hydration cement. ʻO ka ʻoiaʻiʻo, pōkole ka manawa o ka neʻe ʻana o ka ion a i ʻole ka neʻe ʻana a ʻaʻole hiki ke hoʻohālikelike ʻia me ka manawa o ka lohi ʻana i ka wai. ʻO ka adsorption ma waena o cellulose ether a me nā huahana hydration cement i manaʻo ʻia ʻo ia ke kumu maoli no ka lohi o ka hydration cement e cellulose ether. Hoʻopili maʻalahi ʻia ka cellulose ether i ka ʻili o nā huahana hydration e like me ka calcium hydroxide, CSH gel a me ka calcium aluminate hydrate, akā ʻaʻole maʻalahi ka adsorbed e ettringite a me ka unhydrated phase, a ʻoi aku ka kiʻekiʻe o ka adsorption o cellulose ether ma ka calcium hydroxide. ʻO ka CSH gel. No laila, no nā huahana hydration hydration Portland maʻamau, ʻo ka cellulose ether ka lohi ikaika loa i ka calcium hydroxide, ka lohi ikaika loa ma ka calcium, ka lua o ka lohi ma CSH gel, a me ka nāwaliwali loa ma ka ettringite.

Ua hōʻike ʻia nā haʻawina mua i ka adsorption ma waena o ka polysaccharide non-ionic a me ka pae mineral e komo pū me ka hoʻopaʻa ʻana i ka hydrogen a me ka paʻakikī paʻakikī, a ʻo kēia mau hopena ʻelua e loaʻa ma waena o ka hui hydroxyl o polysaccharide a me ka metala hydroxide ma ka ʻili mineral. Liu et al. Hoʻohui hou i ka adsorption ma waena o polysaccharides a me metala hydroxides ma ke ʻano he pilina acid-base, me ka polysaccharides ma ke ʻano he waikawa a me ka metala hydroxides ma ke kumu. No ka polysaccharide i hāʻawi ʻia, ʻo ka alkalinity o ka ʻili mineral e hoʻoholo i ka ikaika o ka pilina ma waena o polysaccharides a me nā minela. Ma waena o nā ʻāpana gelling ʻehā i aʻo ʻia ma kēia pepa, ʻo nā mea metala nui a i ʻole nā ​​mea metala ʻole ʻo Ca, Al a me Si. E like me ke kaʻina o ka hana metala, ʻo ka alkalinity o kā lākou hydroxides ʻo Ca(OH)2>Al(OH3>Si(OH) 4. ʻO ka ʻoiaʻiʻo, ʻo ka solution Si(OH)4 he ʻakika a ʻaʻole adsorb cellulose ether. ʻO ka maʻiʻo o Ca (OH) 2 ma ka ʻili o nā huahana hydration ciment e hoʻoholo i ka mana adsorption o nā huahana hydration a me cellulose ether No ka mea calcium hydroxide, CSH gel (3CaO·2SiO2·3H20), ettringite (3CaO·Al2O3·3CaSO4·32H2O). a me ka calcium aluminate hydrate (3CaO · Al2O3 · 6H2O) i loko o ka maʻiʻo o ka inorganic oxides o CaO he 100%, 58.33%, 49.56% a me 62 .2%. aluminate>CSH gel> ettringite, i kūlike me nā hopena i loko o ka palapala.

ʻO nā huahana hydration o c3S ka nui o Ca(OH) a me csH gel, a he hopena maikaʻi ka cellulose ether iā lākou. No laila, he lohi loa ka cellulose ether ma ka C3s hydration. Ma waho aʻe o ka c3S, ʻo ka sima Portland maʻamau pū kekahi me ka C2s hydration i ʻoi aku ka lohi, kahi e ʻike ʻole ai ka hopena lohi o cellulose ether i ka wā mua. ʻO nā huahana hydration o ka silicate maʻamau pū kekahi ettringite, a ʻo ka hopena lohi o ka cellulose ether he ʻilihune. No laila, ʻoi aku ka ikaika o ka hiki ʻana o ka cellulose ether i nā c3s ma mua o ka sima Portland maʻamau i ʻike ʻia ma ka hoʻāʻo.

E hoʻoheheʻe a hydrate koke ʻo C3A i ka wā e hui ai i ka wai, a ʻo nā huahana hydration maʻamau ka C2AH8 a me c4AH13, a e hoʻokuʻu ʻia ka wela o ka hydration. Ke hiki aku ka hoʻonā o C2AH8 a me c4AH13 i ka saturation, e hoʻokumu ʻia ka crystallization o C2AH8 a me C4AH13 hexagonal sheet hydrate, a e hoʻemi ʻia ka hopena hopena a me ka wela o ka hydration i ka manawa like. Ma muli o ka adsorption o ka cellulose ether i ka ʻili o ka calcium aluminate hydrate (CxAHy), ʻo ka loaʻa ʻana o ka cellulose ether e hoʻopaneʻe i ka crystallization o C2AH8 a me C4AH13 hexagonal-plate hydrate, e hopena i ka emi ʻana o ka hopena a me ka hoʻokuʻu ʻana i ka wela hydration ma mua o kēlā. o C3A maʻemaʻe, e hōʻike ana i ka cellulose ether he nāwaliwali ka wikiwiki wikiwiki i ka C3A hydration. He mea pono e hoʻomaopopo i kēia ho'āʻo, cellulose ether i ka nawaliwali accelerating hiki i ka hydration o ka maemae c3A. Eia naʻe, i loko o Portland sima maʻamau, no ka mea, c3A e hana me ka gypsum e hana i ka ettringite, ma muli o ka mana o ka ca2+ koena i loko o ka slurry solution, cellulose ether e hoʻopaneʻe i ke kukulu ana o ka ettringite, pela e lohi ai i ka hydration o c3A.

Mai nā hopena o HEC, HPMC a me HEMC i ka hydration a me ka hoʻokuʻu wela a me ka hoʻokuʻu ʻana i ka wela o ka sima Portland maʻamau, C3S a me C3A i loko o 72 mau hola, a me nā hopena o HEC i ka hydration a me ka hoʻokuʻu wela a me ka hoʻokuʻu ʻana i ka wela o ka sulfoaluminate. sima i loko o 72 h, hiki ke ike i waena o ka ekolu cellulose ethers i waeʻia, Ka hiki o lohi hydration o c3s a me Portland sima ua ikaika loa i HEC, ukali e HEMC, a nāwaliwali loa ma HPMC. E like me ka C3A e pili ana, hiki i nā cellulose ethers 'ekolu ke hoʻoikaika i ka hydration ma ke ʻano like, ʻo ia hoʻi, ʻo HEC ka ikaika loa, ʻo HEMC ka lua, ʻo HPMC ka nāwaliwali a ikaika loa. Ua hoʻopaʻa ʻia kēia i ka cellulose ether i lohi i ka hoʻokumu ʻana o nā huahana hydration o nā mea gelling.

ʻO nā huahana hydration nui o ka sulfoaluminate cement he ettringite a me Al (OH) 3 gel. E hoʻokaʻawale ka C2S i loko o ka sulfoaluminate cement e hana i ka Ca(OH)2 a me ka cSH gel. No ka mea hiki ke nānā ʻole ʻia ka adsorption o ka cellulose etera a me ka ettringite, a ʻo ka hydration o ka sulfoaluminate wikiwiki loa, no laila, i ka wā mua o ka hydration, he liʻiliʻi ka hopena o ka cellulose etera i ka hydration wela hoʻokuʻu ʻana o ka sulfoaluminate sima. Akā i kekahi manawa o ka hydration, no ka mea e hoʻokaʻawale ʻia nā c2s e hana i ka Ca (OH) 2 a me CSH gel, e hoʻopaneʻe ʻia kēia mau huahana hydration ʻelua e ka cellulose ether. No laila, ua ʻike ʻia ua lohi ka cellulose ether i ka hydration o ka sulfoaluminate cement ma hope o 2 mau hola.

4. Ka hopena

Ma keia pepa, ma o ka isothermal calorimetry hoao, ua hoohalikeia ke kanawai hooikaika a me ka hookumu ana o ka cellulose ether ma ka wela hydration o ka sima Portland ma'amau, c3s, c3A, sulfoaluminate cement a me na mea like ole a me ka aila hookahi i 72 h. ʻO nā hopena nui penei:

(1) Hiki i ka Cellulose ether ke hoʻemi nui i ka hoʻokuʻu ʻana o ka wela hydration o ka sima Portland maʻamau a me ka silicate tricalcium, a ʻoi aku ka nui o ka hopena o ka hoʻemi ʻana i ka nui o ka hoʻokuʻu wela o ka tricalcium silicate; ʻO ka hopena o ka cellulose ether i ka hoʻohaʻahaʻa ʻana i ka wela o ka hoʻokuʻu ʻana o ka sima sulfoaluminate he nāwaliwali loa, akā he hopena nāwaliwali ia i ka hoʻomaikaʻi ʻana i ka hoʻokuʻu wela o ka tricalcium aluminate.

(2) E hoʻopili ʻia ka cellulose ether e kekahi mau huahana hydration, no laila ke kali nei i ka crystallization o nā huahana hydration, e pili ana i ka hoʻokuʻu wela o ka hydration cement. ʻOkoʻa ke ʻano a me ka nui o nā huahana hydration no nā ʻāpana like ʻole o ka cement bill ore, no laila ʻaʻole like ka hopena o ka cellulose ether i kā lākou hydration heat.