1. Ukushisa kwe-hydration
Ngokusho kwejika lokukhululwa kokushisa kwe-hydration ngokuhamba kwesikhathi, inqubo ye-hydration kasimende ivame ukuhlukaniswa ngezigaba ezinhlanu, okungukuthi, isikhathi sokuqala se-hydration (0 ~ 15min), isikhathi sokungeniswa (15min ~ 4h), isikhathi sokusheshisa nokubeka (4h ~ 8h), ukusheshisa kanye nesikhathi sokuqina (8h ~ 24h), kanye nenkathi ye-curing (1 ~ 2h).
Imiphumela yokuhlola ibonisa ukuthi esigabeni sokuqala sokungeniswa (okungukuthi, isikhathi sokuqala se-hydration), lapho inani le-HEMC liyi-0.1% uma liqhathaniswa ne-cement slurry engenalutho, ukuphakama kwe-exothermic kwe-slurry kuthuthukisiwe futhi ukuphakama kwanda kakhulu. Lapho inani leI-HEMCukwanda kuya Uma kungaphezu kuka-0.3%, ukuphakama kokuqala kwe-exothermic kwe-slurry kubambezelekile, futhi inani eliphakeme liyancipha kancane kancane ngokunyuka kokuqukethwe kwe-HEMC; I-HEMC ngokusobala izobambezela isikhathi sokungeniswa kanye nenkathi yokusheshisa ye-slurry kasimende, futhi okuqukethwe okukhulu , isikhathi eside sokungeniswa, isikhathi sokuhlehla kakhulu, kanye nenani eliphakeme le-exothermic elincane; ukuguqulwa kokuqukethwe kwe-cellulose ether akunawo umthelela osobala kubude besikhathi sokuncipha kanye nesikhathi sokuzinza kodaka lukasimende, njengoba kukhonjisiwe kuMfanekiso 3(a) Kuboniswa ukuthi i-cellulose ether inganciphisa nokushisa kwe-hydration yokunamathisela usimende phakathi kwamahora angu-72, kodwa lapho ukushisa kwe-hydration kude kunamahora angu-36 ku-ether ye-ether yokushisa kunomphumela omncane wokushisa kwe-cellulose. namathisela, njengomfanekiso 3(b).
Fig.3 Ithrendi ehlukile yokukhishwa kokushisa kwe-hydration rate yokunamathisela usimende ngokuqukethwe okuhlukile kwe-cellulose ether (HEMC)
2. Mizakhiwo ze-echanical:
Ngokutadisha izinhlobo ezimbili zama-cellulose ether ane-viscosities ye-60000Pa·s kanye ne-100000Pa·s, kwatholakala ukuthi amandla okucindezela odaka olushintshiwe oluxutshwe ne-methyl cellulose ether ehla kancane kancane ngokwanda kokuqukethwe kwalo. Amandla okucindezela odaka olushintshiwe oluxutshwe ne-100000Pa·s viscosity hydroxypropyl methyl cellulose ether akhuphuka kuqala bese ehla ngokunyuka kokuqukethwe kwawo (njengoba kuboniswe kuMfanekiso 4). Kubonisa ukuthi ukufakwa kwe-methyl cellulose ether kuzonciphisa kakhulu amandla okucindezela odaka lukasimende. Uma inani liba likhulu, amandla ayoba mancane; i-viscosity encane, umthelela omkhulu ekulahlekelweni kwamandla okucindezela udaka; I-hydroxypropyl methyl cellulose ether Lapho umthamo ungaphansi kuka-0.1%, amandla okucindezela odaka angakhuliswa ngokufanelekile. Lapho umthamo ungaphezu kuka-0.1%, amandla okucindezela odaka azokwehla ngokunyuka komthamo, ngakho-ke umthamo kufanele ulawulwe ku-0.1%.
Fig.4 3d, 7d kanye 28d amandla okucindezela we-MC1, MC2 kanye ne-MC3 eguquliwe usimende
(i-Methyl cellulose ether, i-viscosity 60000Pa·S, kamuva ebizwa ngokuthi i-MC1; i-methyl cellulose ether, i-viscosity 100000Pa·S, ebizwa ngokuthi i-MC2; i-hydroxypropyl methylcellulose ether, viscosity 100000Pa·S, ebizwa ngokuthi i-MC2).
3. Cisikhathi sokugcina:
Ngokukala isikhathi sokusetha se-hydroxypropyl methylcellulose ether nge-viscosity ye-100000Pa · s ngemithamo ehlukene yokunamathisela usimende, kutholwe ukuthi ngokunyuka komthamo we-HPMC, isikhathi sokuqala sokusetha kanye nesikhathi sokugcina sokusetha sikasimende kwandiswa. Uma ukugxila kungu-1%, isikhathi sokuqala sokusetha sifinyelela emaminithini angu-510, futhi isikhathi sokusetha sokugcina sifinyelela kumaminithi angu-850. Uma kuqhathaniswa nesampula engenalutho, isikhathi sokuqala sokusetha sinwetshwa ngamaminithi angu-210, futhi isikhathi sokugcina sokusetha sinwetshwa ngamaminithi angu-470 (njengoba kuboniswe kuMfanekiso 5). Kungakhathaliseki ukuthi i-HPMC ene-viscosity engu-50000Pa s, 100000Pa s noma 200000Pa s, ingabambezela ukumiswa kukasimende, kodwa uma kuqhathaniswa nama-ether amathathu e-cellulose, isikhathi sokuqala sokusetha nesikhathi sokugcina sokusetha sinwetshwa ngokunyuka kwe-viscosity, njengoba kuboniswe kuMfanekiso 6. Lokhu kungenxa yokuthi i-cellulose ether ikhangisiwe phezu kwezinhlayiya zikasimende, ezivimbela amanzi ukuthi axhumane nezinhlayiya zikasimende, ngaleyo ndlela kubambezeleke ukugeleza kukasimende. Lapho i-viscosity ye-cellulose ether iba nkulu, yilapho ungqimba lwe-adsorption luba lukhudlwana endaweni yezinhlayiya zikasimende, futhi umphumela wokuhlehlisa uphawuleka nakakhulu.
Fig.5 Umthelela wokuqukethwe kwe-cellulose ether ekusetheni isikhathi sodaka
Fig.6 Umthelela wama-viscosity ahlukene we-HPMC ngesikhathi sokusetha sokunamathisela usimende
(MC-5(50000Pa·s), MC-10(100000Pa·s) kanye ne-MC-20(200000Pa·s))
I-Methyl cellulose ether kanye ne-hydroxypropyl methyl cellulose ether izokwandisa kakhulu isikhathi sokumisa udaka lukasimende, olungaqinisekisa ukuthi udaka lukasimende lunesikhathi esanele namanzi okusabela kwe-hydration, futhi ixazulule inkinga yamandla aphansi kanye nesigaba sekwephuzile se-cement slurry ngemva kokuqina. inkinga yokuqhekeka.
4. Ukugcinwa kwamanzi:
Umthelela wokuqukethwe kwe-cellulose ether ekugcinweni kwamanzi wacwaningwa. Kutholakala ukuthi ngokunyuka kokuqukethwe kwe-cellulose ether, izinga lokugcinwa kwamanzi e-mortar likhuphuka, futhi lapho okuqukethwe kwe-cellulose ether kukhulu kuno-0.6%, izinga lokugcinwa kwamanzi livame ukuzinza. Kodwa-ke, uma uqhathanisa izinhlobo ezintathu zama-cellulose ethers (i-HPMC ene-viscosity ye-50000Pa s (MC-5), 100000Pa s (MC-10) kanye ne-200000Pa s (MC-20)), umthelela we-viscosity ekugcinweni kwamanzi uhlukile. Ubudlelwano phakathi kwezinga lokugcinwa kwamanzi yilokhu: MC-5.
Isikhathi sokuthumela: Apr-28-2024