Idethi Yokuthumela: 26, Dec, 2022
1. Izixube zikakhonkolo ezinciphisa amanzi
Izixube ezinciphisa amanzi ziyimikhiqizo yamakhemikhali okuthi uma yengezwe kukhonkolo idale ukuwohloka okufunayo ngenani eliphansi likasimende wamanzi kunalokho eliklanywe ngakho ngokuvamile. Izixube ezinciphisa amanzi zisetshenziselwa ukuthola amandla athile okhonkolo kusetshenziswa okuqukethwe usimende ophansi. Okuqukethwe kusimende okuphansi kubangela ukukhishwa kwe-CO2 okuphansi kanye nokusetshenziswa kwamandla ngevolumu ngayinye kakhonkolo okhiqizwayo. Ngalolu hlobo lwe-admixture, izakhiwo zekhonkrithi ziyathuthukiswa futhi zisiza ukubeka ukhonkolo ngaphansi kwezimo ezinzima. Izinciphisi zamanzi zisetshenziswe ikakhulukazi kumadekhi amabhuloho, imbondela kakhonkolo enezingqimba eziphansi, kanye nokhonkolo wokuchibiyela. Intuthuko yakamuva kubuchwepheshe be-admixture iholele ekuthuthukisweni kwezinciphisi zamanzi eziphakathi nendawo.
2. Ukhonkolo Admixtures: Superplasticizers
Inhloso eyinhloko yokusebenzisa ama-superplasticizers ukukhiqiza ukhonkolo ogelezayo onokuwohloka okuphezulu ebangeni lamasentimitha ayisikhombisa kuya kwayisishiyagalolunye okufanele asetshenziswe ezakhiweni eziqiniswe kakhulu nasekubekweni lapho ukuhlanganiswa okwanele ngokudlidliza kungenakufinyelelwa kalula. Esinye isicelo esikhulu ukukhiqizwa kukakhonkolo oqine kakhulu kuma-w/c asukela ku-0.3 kuye ku-0.4. Kutholakale ukuthi ezinhlotsheni eziningi zikasimende, i-superplasticizer ithuthukisa ukusebenza kukakhonkolo. Inkinga eyodwa ehlotshaniswa nokusebenzisa isinciphisi samanzi esisezingeni eliphezulu kukhonkolo ukulahlekelwa ukuwohloka. Ukhonkolo osebenza kahle kakhulu oqukethe i-superplasticizer ungenziwa ngokumelana nokuncibilika okuphezulu, kodwa okuqukethwe komoya kufanele kwandiswe uma kuqhathaniswa nokhonkolo ngaphandle kwe-superplasticizer.
3. Ukhonkolo Admixtures: Set-Retarding
Izixube zikakhonkolo ezihlehlisayo zisetshenziselwa ukubambezela ukusabela kwamakhemikhali okwenzeka lapho ukhonkolo uqala inqubo yokumisa. Lezi zinhlobo zezingxube zekhonkrithi zivame ukusetshenziselwa ukunciphisa umphumela wamazinga okushisa aphezulu angakhiqiza ukusetha kokuqala okushesha kokukhonkolo. Izixube ezihlehliswayo ezimisiwe zisetshenziswa ekwakhiweni kwendawo egandaywe ngokhonkolo, okuvumela isikhathi esengeziwe sokuqedela umgwaqo ogandaywe ngokhonkolo, kunciphisa izindleko ezengeziwe zokubeka isitshalo esisha seqoqo likakhonkolo endaweni yomsebenzi futhi kusiza ukuqeda amalunga abandayo kukhonkolo. Ama-retarders angasetshenziswa futhi ukumelana nokuqhekeka ngenxa yokuphambuka kwefomu okungenzeka lapho ama-slabs avundlile ebekwa ezingxenyeni. Amaretareda amaningi asebenza futhi njengezinciphisi zamanzi futhi angase afake umoya othile kukhonkolo
4. Ukhonkolo Admixtures: Air-Entraining Agent
Ukhonkolo wokufaka umoya ungakhuphula ukuqina kweqhwa nokuncibilika kukakhonkolo. Lolu hlobo lwe-admixture lukhiqiza ukhonkolo osebenza kakhulu kunokhonkolo ongaqeqeshiwe ngenkathi kunciphisa ukopha nokuhlukaniswa kukakhonkolo omusha. Ukumelana okuthuthukisiwe kukakhonkolo esenzweni sesithwathwa esiqinile noma imijikelezo yokuqhwa/ncibilika. Ezinye izinzuzo ezivela kule ngxube yilezi:
a. Ukumelana okuphezulu nemijikelezo yokumanzisa nokomisa
b. Izinga eliphezulu lokusebenza
c. Izinga eliphezulu lokuqina
Amabhamuza omoya ahlanganisiwe asebenza njengesivimbeli esingokomzimba ngokumelene nokuqhekeka okubangelwa ingcindezi ngenxa yokwanda komthamo wamanzi emazingeni okushisa aqandayo. Izixube zokuzijabulisa zomoya zihambisana cishe nazo zonke izingxube zekhonkrithi. Ngokuvamile kuwo wonke iphesenti elilodwa lomoya ofakiwe, amandla okucindezela azoncishiswa cishe ngamaphesenti amahlanu.
5. Izithako zikakhonkolo: Iyashesha
Izixube zekhonkrithi ezinciphisa ukuncipha zengezwa kukhonkolo ngesikhathi sokuxuba kokuqala. Lolu hlobo lwengxube lunganciphisa ukushwabana kokumiswa kwangaphambi kwesikhathi nesikhathi eside. Izixube ezinciphisa ukushwabana zingasetshenziswa ezimweni lapho ukuqhekeka kokuncipha kungaholela ezinkingeni ezihlala isikhathi eside noma lapho amanani amakhulu amalunga okushwabana engathandeki ngenxa yezizathu zezomnotho noma zezobuchwepheshe. Izixube ezinciphisa ukuncipha, kwezinye izimo, zinganciphisa ukuthuthukiswa kwamandla kokubili eminyakeni yangaphambi kwesikhathi nakamuva.
6.Izingxube zikakhonkolo: Ukunciphisa Ukuncipha
Izixube zekhonkrithi ezinciphisa ukuncipha zengezwa kukhonkolo ngesikhathi sokuxuba kokuqala. Lolu hlobo lwengxube lunganciphisa ukushwabana kokumiswa kwangaphambi kwesikhathi nesikhathi eside. Izixube ezinciphisa ukushwabana zingasetshenziswa ezimweni lapho ukuqhekeka kokuncipha kungaholela ezinkingeni ezihlala isikhathi eside noma lapho amanani amakhulu amalunga okushwabana engathandeki ngenxa yezizathu zezomnotho noma zezobuchwepheshe. Izixube ezinciphisa ukuncipha, kwezinye izimo, zinganciphisa ukuthuthukiswa kwamandla kokubili eminyakeni yangaphambi kwesikhathi nakamuva.
7. Ukhonkolo Inhlanganisela: Corrosion-Inhibiting
Izingxube ezivimbela ukugqwala ziwela esigabeni senhlanganisela yekhethelo futhi zisetshenziselwa ukwehlisa ukugqwala kwensimbi eqinisayo kukhonkolo. Ama-Corrosion inhibitors anganciphisa kakhulu izindleko zokunakekelwa kwezakhiwo zikakhonkolo eziqinisiwe kuyo yonke impilo yesevisi evamile yeminyaka engama-30 - 40. Ezinye izinhlanganisela ezikhethekile zifaka izingxube ezinciphisa ukuncipha kanye nama-alkali-silica reactivity inhibitors. Izingxube ezivimbela ukugqwala zinomthelela omncane emandleni eminyakeni yakamuva kodwa zingasheshisa ukukhula kwamandla okuqala. I-Calcium nitrite based corrosion inhibitors iyasheshisa izikhathi zokubeka ikhonkrithi phezu kwebanga lamazinga okushisa okuphulukisa ngaphandle uma enziwe ngesethi ye-retarder ukuze asuse umphumela wokusheshisa.
Isikhathi sokuthumela: Dec-27-2022
