Umphumela Wesimo Sezulu Ekhwalithini Yokwakhiwa Kwekhonkrithi
Ikhwalithi yokwakhiwa kwekhonkrithi ayinqunywa nje kuphela ngomklamo wengxube, ikhwalithi yezinto zokwakha, kanye namakhono okusebenza, kodwa futhi nangezimo zezulu ngesikhathi sokubumba nokulungisa. Isimo sezulu singasheshisa noma sinciphise inqubo yokumanzisa usimende, sishintshe okuqukethwe komswakama kwengxube, sithinte ukuminyana, futhi sibangele nokuqhekeka kusenesikhathi. Ngakho-ke, ukuqonda imiphumela yesimo sezulu kanye namasu okunciphisa ukonakala kubalulekile ekukhiqizeni ukhonkrithi oqinile nohlala isikhathi eside ohlangabezana nezidingo.
1. Ukhonkolo kanye nokubaluleka kwenqubo yokumanzisa amanzi
Ikhonkrithi ithola amandla ayo ngokusebenzisa ukusabela kwamakhemikhali phakathi kwesimende namanzi okubizwa ngokuthi i-hydration. Lokhu kusabela kukhiqiza imikhiqizo ye-hydration ehlanganisa ama-aggregates ndawonye, yakha isisindo esiqinile nesiqinile. Ukumanzisa kwenzeka kahle lapho umswakama wanele, amazinga okushisa angaphakathi kwebanga elifanele, futhi ukuphazamiseka okufana nokuhwamuka ngokweqile noma ukugeleza kwekhonkrithi ngamanzi emvula kuyagwenywa. Uma isimo sezulu siphazamisa le nqubo, ikhwalithi yokugcina yekhonkrithi ingaphazamiseka, noma ngabe ingxube yokuqala yayinjengoba bekuhleliwe.
2. Umthelela wokushisa okuphezulu (isimo sezulu esishisayo) kukhonkrithi
Isimo sezulu esishisayo—esibonakala ngokushisa komoya okuphezulu, imisebe yelanga enamandla, umswakama ophansi, kanye nemimoya enamandla—ngokuvamile kubangela izinkinga ngomsebenzi wokhonkolo.
a. Ukuhwamuka kwamanzi ngokweqile kanye nokwehla kokusebenza kahle
Emazingeni okushisa aphezulu, amanzi asenhlanganiseni ayahwamuka ngokushesha, aqinise ukhonkolo ngaphambi kokuba ube nethuba lokuqina nokuhleleka. Ngenxa yalokho, izisebenzi zivame ukulingeka ukuba zifake amanzi endaweni ukuze kube lula ukusebenza ngokhonkolo. Lo mkhuba uyingozi ngoba wandisa isilinganiso samanzi-no-simende (isilinganiso se-w/c), okwenza ukhonkolo ube nezimbobo eziningi futhi unciphise amandla awo.
b. Ukuqhekeka kwepulasitiki (ukuqhekeka kwepulasitiki okuncishisiwe)
Uma izinga lokuhwamuka kwamanzi lishesha kunezinga lokopha (amanzi ekhuphukela phezulu), ubuso bekhonkrithi bulahlekelwa amanzi ngokushesha kakhulu futhi bunciphe buseseplastiki. Imifantu emincane ingavela emahoreni ambalwa okuqala ngemva kokuthululwa, ikakhulukazi ezitsheni ezinkulu zaphansi.
c. Ukusheshisa kokuqala kokubopha kanye nobunzima bokuqeda
Amazinga okushisa aphezulu asheshisa ukusabela komswakama, okuholela ezikhathini ezimfushane zokusetha. Lokhu kungenza inqubo yokuqeda ibe nzima futhi kwandise ingozi yokubanda kwamalunga, njengoba kufakwa ukhonkolo olandelayo ngenkathi owedlule usuqalile ukuqina.
d. Umthelela emandleni esikhathi eside
Ngokuthakazelisayo, ukhonkolo oqina ngokushesha kakhulu emazingeni okushisa aphezulu ungabonisa amandla aphezulu okuqala, kodwa isakhiwo esincane esiphumelayo sivame ukuba sincane kakhulu. Ngenxa yalokho, amandla esikhathi eside nokuqina (ukumelana nemvelo) kungancishiswa.
3. Umthelela wokushisa okuphansi (isimo sezulu esibandayo) kukhonkrithi
Isimo sezulu esibandayo sivimbela inqubo yokumuncwa kwesimende. Uma ingaphathwanga kahle, ikhwalithi yesikhonkolo ingathinteka kakhulu.
a. Ukuphuza amanzi kancane kanye namandla aphuzile
Emazingeni okushisa aphansi, ukhonkolo uthatha isikhathi eside ukufinyelela amandla anele. Lokhu kuthinta isimiso sokususwa kwefomu kanye nomthwalo wesakhiwo.
b. Ingozi yokuqandisa amanzi kukhonkrithi
Uma amazinga okushisa ehla eduze noma ngaphansi kweqhwa, amanzi asezimbotsheni zekhonkrithi angabanda futhi anwebeke. Lokhu kwanda kungalimaza isakhiwo sangaphakathi sekhonkrithi encane, okubangela ukulahlekelwa amandla okuhlala njalo, ukukhuhla, noma ukuqhekeka.
c. Ukuqeda nokulungisa kunzima kakhulu
Ezindaweni ezibandayo, amalungiselelo okugcoba kumele aqinisekise ukuthi ukhonkolo uhlala ekushiseni okuphephile ukuze umswakama ungabi khona. Ngaphandle kokuvikelwa kokushisa, indawo ingomile ngokungalingani noma ivezwe eqhweni.
4. Umphumela wemvula ekhwalithini yekhonkrithi
Imvula ingenye yezici zesimo sezulu eziphazamisa kakhulu umsebenzi wokukhipha udoti.
a. Ukuwashwa nokwahlukaniswa kwesimende
Uma lina ngenkathi ukhonkolo usasha, amanzi emvula angageza ukhonkolo wesimende ebusweni, okwenza ukuthi ubuso bube buthakathaka, bube nothuli, noma bube nokuqhekeka.
b. Izinguquko kusilinganiso samanzi nosimende
Imvula engena ebusweni noma engxubeni ingakhuphula ngokungalawuleki okuqukethwe kwamanzi engxubeni. Imiphumela ifana nokwengeza amanzi: amandla okucindezela ayancipha, ukuvuleka kwamanzi kuyanda, kanye nokwanda kokungena kwamanzi.
c. Ukuphazamiseka komsebenzi wokuqeda
Ukuqeda lapho ubuso bumanzi kakhulu kungabangela ukugoba okubuthakathaka (ungqimba oluncane, olufana nosimende). Ngokuhamba kwesikhathi, lolu ngqimba lungaqhekeka, kunciphise ikhwalithi yobuhle kanye nokumelana nokuguguleka.
5. Umthelela womoya nomswakama womoya
Ngaphandle kwezinga lokushisa nemvula, umoya kanye nomswakama ohlobene (RH) kudlala indima enkulu.
a. Imimoya enamandla isheshisa ukuhwamuka kwamanzi
Kuma-slab avele obala, inhlanganisela yomoya namazinga okushisa aphezulu isheshisa ukuhwamuka kwamanzi angaphezulu. Lokhu kwandisa ingozi yokuqhekeka kwepulasitiki futhi kudinga ukuqiniswa okusheshayo.
b. Umswakama ophansi wandisa ukuncishiswa
Umoya owomile ubangela ukuthi ubuso bekhonkrithi bulahlekelwe amanzi ngokushesha. Uma lokhu kwenzeka emahoreni okuqala, ukuqhekeka kwangaphambi kwesikhathi kungenzeka kalula. Ngokuphambene nalokho, umswakama ophezulu usiza ukugcina amanzi ebusweni, kodwa kumele kulinganiswe nokuqina okufanele.
6. Imiphumela yesimo sezulu ekuqineni kwekhonkrithi
Isimo sezulu asigcini nje ngokuthinta amandla okucindezela kodwa futhi nokuqina. Ikhonkrithi engakaze iqine ngenxa yokushisa, imvula, noma umoya ivame ukuba nezimbobo eziningi. Izimbobo eziphezulu zisheshisa ukungena kwamanzi, ama-chloride, ama-sulfate, kanye ne-carbonation. Ngokuhamba kwesikhathi, lokhu kwandisa ingozi yokugqwala kokuqina, ukuchitheka kwekhonkrithi, kanye nokuphila kwesakhiwo okunciphile.
7. Amasu okunciphisa ubungozi: izindlela ezinhle kakhulu zokusebenzisa lo mkhakha
Ukuze kugcinwe ikhwalithi eqinile ngokumelene nokushintshashintsha kwesimo sezulu, kudingeka inhlanganisela yokuhlela, ukuqapha kanye nezindlela zokusebenza ezifanele.
a. Ukuhlela isikhathi sokulingisa
Ukufaka inhlabathi kungahlelwa ngezikhathi ezipholile (ekuseni noma kusihlwa) ezindaweni ezishisayo, noma ngesikhathi sokushisa okuzinzile ezindaweni ezibandayo. Ukuqapha izibikezelo zesimo sezulu kusiza ukugwema ingozi yemvula enkulu.
b. Ukulawulwa kokushisa kwezinto ezibonakalayo
Uma kushisa, i-aggregate inganiselwa, amanzi okuxuba angapholiswa, noma iqhwa eliqhekekile lingasetshenziswa ukwehlisa izinga lokushisa kwekhonkrithi entsha. Uma kubanda, amanzi okuxuba angafudunyezwa futhi i-aggregate ingagcinwa ukuze igweme ukubanda kakhulu.
c. Sebenzisa ingxube efanele
Ama-retarder angasiza ekwandiseni isikhathi sokusetha ezimweni ezishisayo, kuyilapho ama-accelerator angasiza ekusheshiseni amandla ezimweni ezibandayo (ngokucabangela ukuhambisana okufanele kanye nezingozi zokugqwala uma kukhona ama-chloride). Ama-Superplasticizer avumela ukusebenza kahle kakhulu ngaphandle kokwengeza amanzi.
d. Ukuvikelwa ngesikhathi semvula
Nikeza isembozo sesikhashana sendawo yokubumba. Uma lina imvula ngokuzumayo, yeka umsebenzi wokuqeda bese uvikela indawo kuze kube yilapho izimo ziphephile.
e. Ukwelashwa okuqondisiwe
Ukuhlanza "ukuqinisekisa ikhwalithi" yekhonkrithi. Izindlela zokuhlanza zingafaka ukuchelela okuqhubekayo, ukumboza nge-burlap emanzi, ukuhlanza okuhlanganisiwe, noma upulasitiki. Esimweni sezulu esishisayo nesinomoya, ukuhlanza kufanele kuqale kusenesikhathi ukuze kuvinjelwe ukulahleka kwamanzi. Esimweni sezulu esibandayo, sebenzisa ingubo yokuvikela noma i-heater yesikhashana ukuze ugcine izinga lokushisa lekhonkrithi.
f. Ukulawulwa kwamalunga kanye nokuqiniswa kwawo
Isimo sezulu esishisayo sandisa ingozi yokubanda kwamalunga ngoba ukhonkolo uqina ngokushesha. Qinisekisa ukuthi ukhonkolo utholakala njalo, ukuqina kahle kwe-vibrator, kanye namalunga okwakha ahlelwe kahle.
8. Isiphetho
Isimo sezulu siyinto eguquguqukayo evame ukubhekwa “njengengalawuleki,” kodwa umthelela waso ekhwalithini yokwakhiwa kwekhonkrithi ungokoqobo kakhulu futhi ungaphathwa ngendlela efanele yobuchwepheshe. Amazinga okushisa aphezulu angasheshisa ukuhwamuka futhi abangele ukuqhekeka ngaphambi kwesikhathi, amazinga okushisa aphansi avimbela umswakama futhi andise ingozi yokubanda, imvula ingashintsha isilinganiso samanzi nosimende futhi yonakalise indawo, kuyilapho umoya nomswakama kuthinta izinga lokomisa. Ngokuhlela ngokucophelela ukuthunga, ukulawula izinto, ukusetshenziswa kokuxuba okufanele, ukuvikelwa kwendawo, kanye nokulungiswa okuhlelekile, ikhwalithi nokuqina kwekhonkrithi kungagcinwa ngisho nangaphansi kwezimo zezulu ezinzima.
Uma ufisa, ngingaguqula lesi sihloko sibe yinguqulo yezemfundo egcwele izingcaphuno (isib. izinkomba ze-ACI/ASTM/SNI), noma ngisenze sibe usizo kakhulu njengomhlahlandlela we-SOP yasensimini.
