1. Ukubuka konke kwe-cellulose ether (HPMC)
I-Hydroxypropyl methylcellulose (HPMC) iyinhlanganisela ye-cellulose ether esetshenziswa kakhulu, eguqulwa ngamakhemikhali kusuka ku-cellulose yemvelo. Inezakhiwo ezinhle kakhulu zokuncibilika kwamanzi, ukwakha ifilimu, ukuqina kanye nokunamathela, ngakho-ke isetshenziswa kabanzi ezintweni zokwakha. Ukusetshenziswa kwe-HPMC ezintweni ezisekelwe kusimende ikakhulukazi ukuthuthukisa ukugeleza kwayo, ukugcinwa kwamanzi kanye nokulungisa isikhathi sokusetha.
2. Inqubo eyisisekelo yokubeka usimende
Inqubo yokusabela kukasimende namanzi ukuze kwakheke ama-hydrate ibizwa ngokuthi i-hydration reaction. Le nqubo ihlukaniswe ngezigaba eziningana:
Isikhathi sokungenisa: Izinhlayiya zesamente ziqala ukuncibilika, zakha ama-ion e-calcium nama-ion e-silicate, okubonisa isimo sokugeleza kwesikhathi esifushane.
Isikhathi sokusheshisa: Imikhiqizo yokufutha iyanda ngokushesha futhi inqubo yokusetha iqala.
Isikhathi sokuncipha kwe-element: Izinga lokumanzisa liyancipha, usimende uqala ukuqina, bese kwakheka itshe eliqinile lesimende.
Isikhathi sokuzinza: Imikhiqizo yokufutha amanzi ivuthwa kancane kancane futhi amandla ayanda kancane kancane.
Isikhathi sokusetha sivame ukuhlukaniswa sibe isikhathi sokuqala sokusetha kanye nesikhathi sokugcina sokusetha. Isikhathi sokuqala sokusetha sibhekisela esikhathini lapho i-cement paste iqala ukulahlekelwa yi-plasticity, kanti isikhathi sokugcina sokusetha sibhekisela esikhathini lapho i-cement paste ilahlekelwa yi-plasticity ngokuphelele futhi ingena esigabeni sokuqina.
3. Indlela yethonya le-HPMC esikhathini sokusetha usimende
3.1 Umphumela wokuqina
I-HPMC inomphumela obalulekile wokujiya. Ingakhulisa ukujiya kwe-paste yesimende futhi yakhe uhlelo olunamandla aphezulu okujiya. Lo mphumela wokujiya uzothinta ukuhlakazeka kanye nokuthungwa kwezinhlayiya zesimende, ngaleyo ndlela kuthinte inqubekela phambili yokusabela kokujiya. Umphumela wokujiya unciphisa izinga lokufakwa kwemikhiqizo yokujiya ebusweni bezinhlayiya zesimende, ngaleyo ndlela kubambezele isikhathi sokusetha.
3.2 Ukugcinwa kwamanzi
I-HPMC inomthamo omuhle wokugcina amanzi. Ukwengeza i-HPMC ku-paste yesimende kungathuthukisa kakhulu ukugcinwa kwamanzi kwe-paste. Ukugcinwa kwamanzi amaningi kungavimbela amanzi ebusweni besimende ukuthi angahwamuki ngokushesha, ukuze kugcinwe okuqukethwe kwamanzi ku-paste yesimende futhi kwandise isikhathi sokusabela kokumanzi. Ngaphezu kwalokho, ukugcinwa kwamanzi kusiza i-paste yesimende ukuthi igcine umswakama ofanele ngesikhathi senqubo yokupholisa futhi kunciphise ingozi yokuqhekeka okubangelwa ukulahleka kwamanzi kusenesikhathi.
3.3 Ukuncipha kwamanzi emzimbeni
I-HPMC ingakha ifilimu evikelayo emboza ubuso bezinhlayiya zesimende, okuzovimbela ukusabela kokumanzi. Le filimu evikelayo ivimbela ukuxhumana okuqondile phakathi kwezinhlayiya zesimende namanzi, ngaleyo ndlela ibambezele inqubo yokumanzisa yesimende futhi yandise isikhathi sokusetha. Lo mphumela wokulibaziseka ubonakala kakhulu ku-HPMC enesisindo esikhulu sama-molecule.
3.4 I-thixotropy ethuthukisiwe
Ukwengezwa kwe-HPMC kungathuthukisa futhi i-thixotropy ye-simende (okungukuthi, ukugeleza kuyanda ngaphansi kwesenzo samandla angaphandle futhi kubuyela esimweni sokuqala ngemva kokuba amandla angaphandle esusiwe). Le mpahla ye-thixotropic isiza ekuthuthukiseni ukusebenza kwe-simende slurry, kodwa maqondana nesikhathi sokusetha, le thixotropy ethuthukisiwe ingabangela ukuthi i-slurry isabalale kabusha ngaphansi kwamandla okusika, okwandise isikhathi sokusetha.
4. Ukusetshenziswa okungokoqobo kwe-HPMC okuthinta isikhathi sokusetha usimende
4.1 Izinto zokwakha phansi ezizilinganisayo
Ezintweni zokwakha phansi ezizilinganisayo, usimende udinga isikhathi eside sokuqala sokuhlela ukusebenza kokuhlela nokusika. Ukwengeza i-HPMC kungandisa isikhathi sokuqala sokuhlela usimende, okuvumela izinto zokuzilinganisa ukuthi zibe nesikhathi eside sokusebenza ngesikhathi sokwakha, kugwenywe inkinga ebangelwa ukusethwa kwe-slurry yesimende ngaphambi kwesikhathi ngesikhathi sokwakha.
4.2 Udaka oluxutshwe kusengaphambili
Ku-mortar exutshwe kusengaphambili, i-HPMC ayigcini nje ngokuthuthukisa ukugcinwa kwamanzi kwe-mortar, kodwa futhi yandisa isikhathi sokusetha. Lokhu kubaluleke kakhulu ngezikhathi lapho kuthuthwa isikhathi eside nesikhathi sokwakha, okuqinisekisa ukuthi i-mortar igcina ukusebenza kahle ngaphambi kokusetshenziswa futhi igwema ubunzima bokwakha obubangelwa isikhathi esifushane kakhulu sokusetha.
4.3 Udaka oluxutshwe okomile
I-HPMC ivame ukungezwa ku-mortar exutshwe okomile ukuze kuthuthukiswe ukusebenza kwayo kokwakhiwa. Umphumela wokujiya we-HPMC wandisa ukujiya kwe-mortar, okwenza kube lula ukuyisebenzisa kanye nokulinganisa ngesikhathi sokwakhiwa, futhi wandisa isikhathi sokusetha, okunikeza abasebenzi bokwakha isikhathi esanele sokwenza izinguquko.
5. Izici ezithinta isikhathi sokusetha usimende yi-HPMC
5.1 Inani lokwengeza le-HPMC
Inani le-HPMC elingeziwe liyisici esibalulekile esithinta isikhathi sokubeka i-simende. Ngokuvamile, lapho inani le-HPMC elingeziwe likhulu, kulapho isikhathi sokubeka i-simende sibonakala khona. Lokhu kungenxa yokuthi ama-molecule e-HPMC amaningi angamboza izindawo eziningi zezinhlayiya ze-simende futhi avimbele ukusabela kwamanzi.
5.2 Isisindo sama-molecule e-HPMC
I-HPMC yesisindo sama-molecule ahlukene inemiphumela ehlukene esikhathini sokubeka sikamende. I-HPMC enesisindo sama-molecule aphezulu ivame ukuba nomphumela wokujiya oqinile kanye namandla okugcina amanzi, ngakho-ke ingandisa isikhathi sokubeka kakhulu. Nakuba i-HPMC enesisindo sama-molecule aphansi ingandisa nesikhathi sokubeka, umphumela ubuthakathaka kakhulu.
5.3 Izimo zemvelo
Izinga lokushisa elizungezile kanye nomswakama kuzothinta nomphumela we-HPMC esikhathini sokusetha usimende. Endaweni yokushisa okuphezulu, ukusabela kokumanzisa usimende kuyasheshiswa, kodwa isici sokugcina amanzi se-HPMC sinciphisa lo mphumela. Endaweni yokushisa okuphansi, ukusabela kokumanzisa ngokwako kuhamba kancane, futhi ukuqina nomphumela wokugcinwa kwamanzi we-HPMC kungabangela ukuthi isikhathi sokusetha usimende sithathe isikhathi eside kakhulu.
5.4 Isilinganiso samanzi nosimende
Izinguquko kusilinganiso samanzi nosimende zizothinta nomphumela we-HPMC esikhathini sokusetha usimende. Ngesilinganiso samanzi nosimende esiphezulu, kunamanzi amaningi ku-paste yesimende, futhi umphumela wokugcina amanzi we-HPMC ungase ube nomthelela omncane esikhathini sokusetha. Ngesilinganiso samanzi nosimende esiphansi, umphumela wokujiya we-HPMC uzoba sobala kakhulu, futhi umphumela wokwandisa isikhathi sokusetha uzoba mkhulu kakhulu.
Njengesengezo esibalulekile sikasimende, i-HPMC ithinta kakhulu isikhathi sokusetha sikasimende ngezindlela ezahlukahlukene ezifana nokuqina, ukugcinwa kwamanzi, kanye nokubambezeleka kokusabela kokumanzi. Ukusetshenziswa kwe-HPMC kungandisa isikhathi sokuqala nesokugcina sokusetha sikasimende, kunikeze isikhathi eside sokusebenza kokwakha, futhi kuthuthukise ukusebenza kwezinto ezisekelwe kukasimende. Ezisetshenzisweni ezisebenzayo, izici ezifana nenani le-HPMC elingeziwe, isisindo sama-molecule, kanye nezimo zemvelo zinquma ngokuhlanganyela umphumela walo othize esikhathini sokusetha sikasimende. Ngokulungisa lezi zici ngokunengqondo, ukulawulwa okunembile kwesikhathi sokusetha sikasimende kungafinyelelwa ukuze kuhlangatshezwane nezidingo zamaphrojekthi okwakha ahlukene.
Isikhathi sokuthunyelwe: Juni-21-2024