Idethi Yokuthumela:3, Sep, 2024

7. Umthelela wokuxuba isikhathi nesivinini sokuxuba

Isikhathi sokuxuba sinomthelela oqondile kokuqukethwe kokhonkolo kanye nomphumela wokuhlakazeka kwe-concrete admixtures kukhonkolo, futhi kuthinta ngokungaqondile ukusebenza, izakhiwo zemishini nokuqina kokhonkolo. Uma i-mixer igijima ngokushesha kakhulu, kulula ukulimaza isakhiwo se-colloidal kusimende kanye ne-membrane yongqimba kagesi kabili ebusweni bezinhlayiya ze-cement, okuzogcina kuthinte isikhathi sokusetha kanye nokwehla kokhonkolo ngezinga elikhulu. Isivinini sokuxuba sidinga ukulawulwa phakathi kwemizuzu engu-1.5-3. Uma indlela yokuxuba okomile isetshenziswa, ukhonkolo ungaxutshwa ngokulinganayo ngokusebenzisa isinciphisi samanzi ngokunengqondo. Uma isisombululo sidinga ukungezwa, amanzi adinga ukuncishiswa ekuxubeni ngesikhathi sokucushwa kwesinciphisi samanzi ukuze kuqinisekiswe ukufaneleka komklamo wesilinganiso samanzi-samente. Ukuze kuqinisekiswe ukuwohloka kokhonkolo futhi unikeze ukudlala okuphelele endimeni yokunciphisa amanzi, indlela yokuxuba emva kokuxuba ingasetshenziswa ngokuqondile. Ngokungafani nendlela yokwengeza yokunciphisa amanzi esebenza kahle kakhulu, ukukhululeka kokuxuba ukhonkolo kungaqinisekiswa ngokusebenzisa indlela yokuxuba emva kokuxuba ngokufanele. Uma iloli le-mixer lidingeka ukuze kuthuthwe ukhonkolo, isinciphisi samanzi singangezwa elolini lokuxuba imizuzu emi-2 ngaphambi kokulayishwa ukuze kukhuliswe ngokunengqondo isivinini sokuxuba eloli lokuhlanganisa futhi sithuthukise umphumela wokulahla.

8. Umthelela wezinga lokushisa elizungezile nomswakama

Isikhathi sokumisa, isivinini sokuqina namandla okuqala ezingxube zikakhonkolo kuhlobene ngokuqondile nezinga lokushisa lokuphulukisa. Ngemva kokwengeza isinciphisi samanzi, lesi simo sibonakala sisobala, futhi umphumela uzoba mkhulu kakhulu lapho isikhathi sokusetha singaphansi kwama-degree Celsius angu-20. Ngokuvamile, izinga lokushisa liphakeme kakhulu, izinga lokushisa likasimende liyashesha, futhi izinga lokuhwamuka kwendawo kakhonkolo lizoba ngokushesha. Amanzi amahhala ngaphakathi kwekhonkrithi azokwengezwa ngokuqhubekayo endaweni ekhonkolo ngokusebenzisa i-capillary, ngokuqhubekayo asheshise umphumela we-hydration we-samente. Amanzi amahhala kukhonkolo ayahwamuka futhi ancishiswe, okuqhubeka kubangela ukulahlekelwa kokuwohloka kokhonkolo. Ngaphezu kwalokho, umphumela wokuvinjelwa kwezinye izixube zikakhonkolo uzoncishiswa kakhulu ube ngaphezu kuka-30 degrees Celsius. Ngakho-ke, uma kudingekile ukusebenza endaweni yokushisa ephezulu, kuyadingeka ukwandisa ngokunengqondo inani le-concrete admixtures ukuze ugweme ngokuphumelelayo ukuvela kokuhwamuka kwamanzi. I-Wood calcium inesakhiwo esithile sokusetha kancane. Ingaba namandla athile esakhiwo kuphela ngemva kokuthulula isikhathi eside. Ngesikhathi sokusebenza kokulungisa, kuyadingeka ukwandisa isikhathi sokuma esimile ngokwanele futhi uklame umthamo ngokwesayensi. Uma kungenjalo, ukhonkolo ujwayele ukuqhekeka okungathi sína, ukuxega kwendawo kanye nokuqhuma ngesikhathi sokusetshenziswa. Enqubweni yokusebenzisa isinciphisi samanzi esisebenza kahle kakhulu, ngenxa yokungena komoya ophansi, umphumela wokusetha kancane awukwazi ukuqinisekiswa, futhi isikhathi eside kakhulu sokuma esimile asidingeki phakathi nenqubo yokuphulukisa isitimu. Ngakho-ke, ohlelweni lokwengeza izixube, umsebenzi wokulungisa ofanele kufanele wenziwe ngokucophelela ukuze kugwenywe ukuhwamuka okukhulu kwamanzi ngesikhathi sokulungiswa.

9. Isikhathi sokugcina usimende

Ngaphansi kwezimo ezijwayelekile, isikhathi esifushane sokugcina usimende, sizovela esisha, futhi umphumela we-plasticization we-cement uzoba mubi kakhulu. Lapho usimende uba musha, iba namandla amandla okushaja okuphozithivu, kanye nama-surfactants e-ionic engeziwe ekhangayo. Kusimende osanda kucutshungulwa, izinga lawo lokunciphisa amanzi liphansi futhi ukulahlekelwa ukuwohloka kuyashesha. Ukuze usimende unesikhathi eside sokugcina, lezi zinkinga zingagwenywa kahle.

10. Okuqukethwe kwe-alkali kusimende

Okuqukethwe kwe-alkali nakho kunomthelela oqondile ekuguquguqukeni kukasimende nesinciphisi samanzi. Njengoba okuqukethwe kwe-alkali kusimende kwanda, umphumela wokwenza ipulasitiki usimende uzowohloka. Uma okuqukethwe kwe-alkali kweqa ububanzi obuthile, kuzoba nomthelela omubi kakhulu esikhathini sokusetha nokuwa kukasimende. Ngaphezu kwalokho, uhlobo lwe-alkali kusimende nalo lunomthelela oqondile ekusetshenzisweni kokunciphisa amanzi. Ngaphansi kwezimo ezijwayelekile, uma i-alkali ikhona ngesimo se-sulfate, umphumela wayo ekunciphiseni amanzi ungaphansi kwalokho osesimweni se-hydroxide.

11. I-Gypsum kusimende

Ngokungeza i-gypsum kasimende kusimende, ukugeleza kukasimende kungabambezeleka kakhulu, futhi ukukhangisa okuqondile kukasimende nesinciphisi samanzi kungagwenywa, ngaleyo ndlela kuthuthukiswe ngempumelelo ukuguquguquka kukasimende nesinciphisi samanzi. Ngokusho kwenani elikhulu lezifundo, ngemuva kokwengeza inani elithile le-gypsum kusimende, i-adsorption yokunciphisa amanzi ku-cement mineral C3A ingancishiswa ngokuphumelelayo. Lokhu kungenxa yokuthi i-gypsum ne-C3A zingasabela zenze i-calcium sulfonate, ezovala ngokuqondile ingaphezulu le-C3A, igweme ukugeleza okwengeziwe kwe-C3A, okungenza buthaka kakhulu ukufakwa kwezinhlayiya ze-C3A kusinciphisi samanzi. Izinhlobo ezahlukene ze-gypsum zinamazinga ahlukene okuncibilika kanye ne-solubilities. Uhlobo nokuqukethwe kwegypsum kasimende kunomthelela oqondile kakhulu ekuguquguqukeni phakathi kukasimende nesinciphisi samanzi. I-pore fluid sulfate ku-samente ukhonkolo ngokuyinhloko ivela ku-sulfate eyakhiwe usimende we-silicate, ozoba nomthelela oqondile kakhulu ekuphenduleni kwe-cement hydration kanye nokusebenza kwekhonkrithi ye-silicate. Ama-ion e-sulfate ku-gypsum ngokuvamile abhekana nezinguquko ezahlukene ngesikhathi sokugaya. Uma izinga lokushisa lokugaya liphezulu, i-dihydrate gypsum izophelelwa amanzi kancane bese yenza i-hemihydrate gypsum. Uma izinga lokushisa ngaphakathi kwesigayo liphezulu kakhulu, inani elikhulu le-hemihydrate gypsum lizokwakhiwa kule nqubo, okuzogcina kuholele ekuveleni kokumiswa kwe-sement pseudo. Ngosimende onezingxenye ze-alkaline sulfate encane ngokuqhathaniswa, ngaphansi kwe-adsorption eqinile yezinciphisi zamanzi ezisekelwe ku-sulfonic acid, kuzobangela ngokuqondile ukuwohloka kukakhonkolo kwehle ngokushesha okukhulu. Uma okuqukethwe kwe-sulfate encibilikayo kukhuphuka, ukukhangiswa kwezinciphisi zamanzi ezisebenza kahle kakhulu kuzobonisa ithrendi eyehlayo efana ne-quasi-linear.

12. Izinsiza zokugaya usimende

Umphumela wokugaya usimende ungathuthukiswa kakhulu ngokusebenzisa izinsiza zokugaya usimende ngokunengqondo. Ekukhiqizeni usimende ezinkampanini eziningi zikasimende zakwamanye amazwe, izinsiza zokugaya zivame ukusetshenziswa ngobuningi. Eminyakeni yamuva nje, ngemva kokuqaliswa kwezindinganiso ezintsha zikasimende ezweni lami, izidingo zamandla nokucoliseka kukasimende ziye zathuthukiswa, okubeke phambili izidingo eziphakeme zokusebenzisa izinsiza zokugaya. Njengamanje, kunezinhlobo eziningi zezinsiza zokugaya usimende, futhi isibalo sabakhiqizi bosizo lokugaya ezweni lami sibonisa umkhuba wokwanda okuqhubekayo. Abakhiqizi abahlukahlukene bosizo lokugaya usimende baqhubeke nokutshala imali ocwaningweni nasekuthuthukisweni kwezinsiza zokugaya ezongayo, ezisebenza kahle nezisebenziseka kalula. Kodwa-ke, abanye abakhiqizi bosizo lokugaya banaka kakhulu izindleko zokukhiqiza futhi batshale imali encane ocwaningweni lokusebenza kosizo lokugaya, olunomthelela omubi kakhulu ekusetshenzisweni kwayo: ① Ukusetshenziswa kwezinto eziqukethe usawoti we-halogen kungenzeka kubangele ukugqwala. wemigoqo yensimbi ngaphakathi kukakhonkolo. ② Ukusetshenziswa kwe-lignin sulfonate eningi kuholela enkingeni engathi sína yokungahambisani phakathi kukasimende nezingxube zikakhonkolo. ③ Ukuze kuncishiswe ngempumelelo izindleko zokukhiqiza, inani elikhulu lemfucuza yezimboni livame ukusetshenziswa, elinomthelela omubi kakhulu ekuqineni kukakhonkolo. Enqubweni yamanje yokukhiqiza ukhonkolo, okuqukethwe kwe-alkali ne-chloride ion, uhlobo lwe-gypsum, namaminerali e-clinker kunomthelela oqondile kakhulu ekusabalaliseni izinhlayiya zikasimende. Ekusetshenzisweni kwezinsiza zokugaya, ukuqina kukasimende akunakunikelwa. Ukwakhiwa kwezinsiza zokugaya kuyinkimbinkimbi. Kuphela ngokusebenzisa izinsiza zokugaya ngokunengqondo lapho umphumela wokhonkolo ungaqinisekiswa. Phakathi nenqubo yokukhiqiza, abakhiqizi bosizo lokugaya kufanele babe nokuqonda okuphelele kwenqubo yokugaya yenkampani, futhi baphathe kahle izinhlobo zezinsiza zokugaya kanye nokugreda kwezinhlayiyana zikasimende.

13. Isilinganiso sokuxuba ukwakhiwa

Isilinganiso sokuxuba ukwakhiwa siyingxenye yenkinga yokuklama ubunjiniyela, kodwa sinomthelela oqondile kakhulu ekuhambisaneni kwezixube zikakhonkolo nosimende. Ngokusho kwedatha efanelekile, uma isilinganiso sesihlabathi siphezulu kakhulu, kulula ukubangela ukwehla kwe-fluidity yengxube kakhonkolo, futhi ukulahlekelwa kwe-slump kukhulu kakhulu. Ukwengeza, ukuma, ukumuncwa kwamanzi kanye nokuhlelwa kwamatshe esilinganisweni sokuxuba ukhonkolo kuzophinde kuthinte ukwakhiwa, ukugcinwa kwamanzi, ukuhlangana, uketshezi kanye nokwakheka kokhonkolo ngezinga elithile. Ukuhlola okufanelekile kubonisa ukuthi ngokunciphisa isilinganiso sikasimende wamanzi, amandla kakhonkolo angathuthukiswa ngezinga elithile. Ngaphansi kwesimo sokusetshenziswa kahle kwamanzi, izakhiwo ezihlukahlukene zekhonkrithi ze-samente zingasetshenziswa ngokugcwele, ukuze i-plasticity yayo ithuthukiswe ngokugcwele, ukugxila kwe-admixtures kuqinisekiswe, futhi ukuhambisana kwe-admixtures kanye nosimende kungathuthukiswa.