Imikhiqizo kasimende, njengokhonkolo, udaka nezinye izinto zokwakha, isetshenziswa kakhulu ezakhiweni zesimanje. Ama-cellulose ethers (afana ne-hydroxypropyl methylcellulose (HPMC), i-hydroxyethyl methylcellulose (HEMC), njll.) ayizithasiselo ezibalulekile ezingathuthukisa kakhulu ukusebenza kwemikhiqizo ye-cement. Ukuze uzuze lezi zakhiwo ezinhle kakhulu, kubalulekile ukwazi nokulawula ukusebenza kwama-cellulose ethers.
1. Izakhiwo eziyisisekelo nemisebenzi yama-cellulose ethers
Ama-cellulose ether ayikilasi lokuphuma kwamakhemikhali e-cellulose yemvelo, lapho iqembu le-hydroxyl lithathelwa indawo yiqembu le-ether ngokusabela kwe-etherification. Izinhlobo ezahlukene zama-cellulose ethers zingahlanganiswa ngokuya ngohlobo kanye nenani lama-substitute, futhi uhlobo ngalunye lunendima ehlukile emikhiqizweni kasimende.
I-viscosity ye-cellulose ethers:
I-viscosity ye-cellulose ethers ithinta ngokuqondile i-rheology nokuzinza kwe-cement paste. I-high-viscosity cellulose ethers ingathuthukisa ukugcinwa kwamanzi namandla okubopha kokunamathisela, kodwa angase ehlise ukugeleza kwawo. I-low-viscosity cellulose ethers isiza ukuthuthukisa ukusebenza kanye noketshezi.
I-Degree of substitution (DS) kanye ne-molar substitution (MS):
Izinga lokushintsha kanye nokushintshwa kwe-molar ye-cellulose ethers inquma ukuncibilika kwayo kanye ne-viscosity yesisombululo. Izinga eliphakeme lokushintsha kanye nokufakwa esikhundleni kwe-molar ephezulu ngokuvamile kungathuthukisa ukugcinwa kwamanzi nokuzinza kwama-cellulose ethers.
Ukuncibilika kwe-cellulose ethers:
Izinga lokuncibilika nokuncibilika kwama-cellulose ethers kuthinta ukufana kokunamathisela usimende. Ama-cellulose ether ane-solubility enhle angakha isisombululo esifanayo ngokushesha, ngaleyo ndlela aqinisekise ukufana nokuzinza kokunamathisela.
2. Khetha ama-cellulose ether afanelekile
Izimo zohlelo lokusebenza ezihlukene zinezidingo ezihlukile zokusebenza kwama-cellulose ethers. Ukukhetha uhlobo olulungile kanye nokucaciswa kwe-cellulose ether kungathuthukisa kakhulu ukusebenza kwemikhiqizo usimende:
Izibophezelo:
Kuzinhlelo zokusebenza ezifana nokunamatheliswa kwamathayela nezinsimbi ze-plaster, ama-high-viscosity cellulose ethers (afana ne-HPMC) anganikeza ukunamathela okungcono kanye nokumanzisa okuhlala njalo, ngaleyo ndlela kuthuthukise ukusebenza kokwakhiwa namandla okugcina okubopha.
Izinto ezigcina amanzi:
Kumabhodwe okuzilinganisa kanye namathayela asekelwe kusimende, ama-cellulose ethers anokugcinwa kwamanzi okuphezulu (okufana ne-HEMC) ayadingeka. Ukugcinwa kwamanzi okuphezulu kusiza ukuvimbela ukulahleka kwamanzi ngaphambi kwesikhathi, ngaleyo ndlela kuqinisekisa ukusabela okwanele kwe-hydration kanye nesikhathi eside sokusebenza.
Izinto zokuqinisa:
Ama-cellulose ether asetshenziselwa ukuthuthukisa amandla emikhiqizo kasimende adinga ukuba nokuhlakazeka okuhle kanye ne-viscosity emaphakathi ukuze kuthuthukiswe ukufana namandla e-matrix.
3. Lungiselela indlela yokwengeza
Ukulawula indlela yokwengeza ye-cellulose ether emikhiqizweni kasimende kubalulekile ukuze kwandiswe ukusebenza kwayo kahle. Okulandelayo izindlela ezimbalwa ezivamile zokuthuthukisa:
Indlela ye-Premixing:
Xuba i-cellulose ether nezinye izinto eziyimpushana ezomile kusengaphambili. Le ndlela ingagwema ukwakheka kwe-agglomeration ye-cellulose ether ngemva kokuxhumana okuqondile namanzi, ngaleyo ndlela iqinisekise ukuhlakazeka kwayo okufanayo ku-slurry.
Indlela yokuhlanganisa okumanzi:
Engeza i-cellulose ether kusimende kancane kancane. Le ndlela ifaneleka esimweni lapho i-cellulose ether ichitheka ngokushesha futhi isiza ukwakha ukumiswa okuzinzile.
Indlela yokwengeza ehlukaniswe izigaba:
Enqubweni yokulungisa udaka lukasimende, ukwengeza i-cellulose ether ezingxenyeni kungaqinisekisa ukusatshalaliswa kwayo okufanayo kuyo yonke inqubo yokulungiselela futhi kunciphise i-agglomeration.
4. Lawula izici zangaphandle
Izici zangaphandle ezifana nezinga lokushisa, inani le-pH, nezinga lokunyakazisa kunomthelela omkhulu ekusebenzeni kwe-cellulose ether.
Ukulawula izinga lokushisa:
I-solubility kanye ne-viscosity ye-cellulose ether izwela kakhulu izinga lokushisa. Amazinga okushisa aphakeme asiza i-cellulose ether ukuthi incibilike ngokushesha, kodwa ingase futhi ibangele ukuba i-viscosity yesixazululo yehle. Izinga lokushisa kufanele lilungiswe ngokuya ngesimo sohlelo oluthile ukuze kuqinisekiswe ukusebenza kahle nokusebenza kahle.
Ukulungiswa kwe-pH: Inani le-pH lokunamathisela usimende ngokuvamile lisebangeni eliphezulu le-alkaline, kuyilapho ukunyibilika kanye ne-viscosity ye-cellulose ether kushintshashintsha ngokushintsha kwevelu ye-pH. Ukulawula ivelu ye-pH ngaphakathi kwebanga elifanele kungamisa ukusebenza kwe-cellulose ether.
Izinga lokunyakazisa: Izinga lokunyakazisa lithinta umphumela wokuhlakazwa kwe-cellulose ether ekunamathiseleni kukasimende. Izinga lokunyakazisa eliphezulu kakhulu lingaholela ekwethulweni komoya nasekuhlanganisweni kwe-cellulose ether, kuyilapho izinga lokunyakazisa elimaphakathi lisiza ukusabalalisa ngokulinganayo nokuncibilikisa i-cellulose ether.
5. Ukuhlaziywa kwamacala kanye nokusikisela okusebenzayo
Ngokuhlaziywa kwecala langempela, singaqhubeka nokuqonda ukusetshenziswa kanye nesu lokwenza kahle le-cellulose ether emikhiqizweni ehlukene kasimende:
I-adhesive yethayela esebenza kahle kakhulu: Lapho inkampani ikhiqiza okokunamathisela kwamathayela okusebenza okuphezulu, kwatholakala ukuthi ukugcinwa kwamanzi omkhiqizo wokuqala kwakunganele, okubangele ukuncipha kwamandla okubopha ngemva kokwakhiwa. Ngokwethula i-HEMC egcina amanzi aphezulu kanye nokulungisa inani layo lokwengeza kanye nendlela yokwengeza (usebenzisa indlela ye-premixing), ukugcinwa kwamanzi namandla okubopha okunamathelayo kwethayela kwathuthukiswa ngempumelelo.
Impahla yaphansi ezilinganisa yona: Impahla yaphansi ezilinganisa yona esetshenziswa kuphrojekthi ethile ibinoketshezi olubi kanye nokucaba okungekuhle kwendawo ngemuva kokwakhiwa. Ngokukhetha i-HPMC ene-viscosity ephansi kanye nokwandisa izinga elishukumisayo nokulawula izinga lokushisa, uketshezi kanye nokusebenza kokwakhiwa kwe-slurry kuyathuthukiswa, okwenza indawo yokugcina yaphansi ibe bushelelezi.
Ukulawula ukusebenza kwe-cellulose ether emikhiqizweni kasimende kuyisihluthulelo sokuthuthukisa ukusebenza kwempahla kanye nekhwalithi yokwakha. Ngokukhetha uhlobo olulungile lwe-cellulose ether, ukukhulisa indlela yokwengeza, nokulawula izici ezithonya zangaphandle, izici ezibalulekile zemikhiqizo kasimende njengokugcina amanzi, ukunamathela, kanye noketshezi kungathuthukiswa kakhulu. Kuzinhlelo zokusebenza ezingokoqobo, kuyadingeka ukuqhubeka nokwandisa futhi ulungise ukusetshenziswa kwe-cellulose ether ngokuya ngezidingo ezithile kanye nezimo zohlelo lokusebenza ukuze kuzuzwe imiphumela engcono kakhulu.
Isikhathi sokuthumela: Jun-26-2024