Zindikirani za zomwe zili ndi chitetezo: Awa ndi zolemba zamaphunziro zakale, osati zaukadaulo, projekiti kapena malangizo antchito. Ziwerengero ndi ziwerengerozi zatengedwa kuchokera m’nkhani yoyambirira ndipo siziyenera kutanthauziridwa ngati kutsimikiziridwa ndi miyezo yamasiku ano. Kusankhidwa, kuyesa, kusungirako ndi kugwiritsa ntchito simenti kuyenera kukhala motsatira malangizo a wopanga, malamulo ogwira ntchito komanso mapangidwe a injiniya woyenerera. Zithunzizi ndi zowonetsera ndipo sizikuyimira mapulojekiti otsimikizika a Savo Kusić.
Simenti si gawo lazogulitsa zatsopano zamakampani. Zomwe zidapangidwa pakadali pano ndi mazenera amatabwa, mazenera a matabwa a aluminiyamu ndi zitseko. Pantchito inayake, mutha kutumiza pempho la mawu.
Zambiri
Simenti ndi zomangira za hydraulic: zikasakanizidwa ndi madzi, zimauma kukhala miyala yamtengo wapatali pakapita nthawi, pansi pa madzi komanso mumlengalenga. Kachiwiri, kuchiritsa kwathunthu kumatheka kokha ngati matope asungidwa monyowa panthawi yochiritsa, makamaka m’masiku oyamba.
Kuumitsa komveka bwino komanso koyezera kuyenera, ngakhale mkatikati mwa chirimwe, kungoyambira pambuyo pa kusakaniza koyenera kwa simenti. Malingana ndi miyezo yomwe yatchulidwa m’malemba oyambirira, chiyambi cha kuumitsa chiyenera kuonekera pasanathe ola limodzi mutapanga simenti slurry. Kutha kwa mgwirizano pa kutentha kuchokera ku 18 mpaka 21 °C kumachitika, monga lamulo, osapitirira zinayi komanso pasanathe maola 12.
Pogwira ntchito potentha kwambiri, kuumitsa kuyenera kuchepera pang’ono poyerekeza ndi kuuma kwa kutentha kwanthawi zonse, pomwe pakutentha kwakukulu kuyenera kukhala kochepa.
Kulemera kwa simenti yolimba kuyenera kukhala kokhazikika pakuchuluka. Mphamvu sayenera kuchepa pakapita nthawi chifukwa zikuchokera simenti kapena chikoka cha chisanu, zakumwa ndi zinthu zina. Ming’alu yobwera chifukwa cha kuchepa kwa matope ndi konkire imatha kupewedwa ndi ntchito yoyenera ndi chisamaliro, ndipo momwe zinthuzi zingakwaniritsidwire zimatengera luso laukadaulo la simenti.
Pantchito zolimba za konkriti ndikumanga milatho, molingana ndi nkhani yoyambirira, simenti yokhayo yokhazikika ndi simenti yamtengo wapamwamba ingagwiritsidwe ntchito. Zanenedwanso kuti munthu ayenera kugwiritsa ntchito simenti zomwe kupanga kwake kumayang’aniridwa ndi mabungwe kuti asunge miyezo yomwe ili ndi chizindikiro chawo. Pazifukwa zapadera, monga misewu ya konkire yodzaza kwambiri, simenti zovomerezeka zovomerezeka ndizovomerezeka.
Pamene kuli kofunikira kwambiri kupeza konkire yapamwamba kwambiri panthawi yochepa kwambiri, mwachitsanzo popanga milu, simenti ya alumina imaganiziridwa. Kapangidwe kake ndi kosiyana kwambiri ndi simenti ya Portland, ndipo aluminium oxide (Al₂O₃) imayang’anira kapangidwe kake.
*Fanizo - simenti yaufa ya alumina.
Mankhwala a simenti
Tebulo lowunikiridwa la simenti zamalonda likuwonetsa zambiri zamitundu yamitundu iliyonse. Zikuwonetsa kuti laimu mu simenti yonyezimira ya Portland nthawi zambiri imakhala yocheperapo kuposa simenti yakale ya Portland, pomwe simenti yosungunula imakhala ndi laimu wocheperako. Simenti zoyera za portland zimapezeka ndi chitsulo chochepa kwambiri.
Tebulo losunga zakale — kusanthula simenti zamalonda kuchokera m’nkhani yoyambirira.
Maganizo okhudza kapangidwe ka simenti yoyenera kwambiri, yogwiritsidwa ntchito wamba kapena ntchito zina zomanga, nthawi zambiri amasintha ndikusiyana. Kusanthula kwamankhwala kokha sikumapereka chidziwitso chonse. Imawonetsa ogula, ngati palibe mapangano apadera, kaya miyeso kapena mikhalidwe yowonjezera idalemekezedwa panthawi yopanga komanso ngati mapangidwe a simenti ali m’malire anthawi zonse kapena amapatuka kwa iwo.
Kuyamba ndi kutha kwa kumanga
Ngati kuyika kwa simenti kumayambira konkire isanayambe, ikhoza kusokoneza chitukuko cha mphamvu ya simenti ndi konkire yokha. Pofuna kupewa zinthu ngati zotere, nkhani yoyambirira imalimbikitsa kuyesedwa pafupipafupi kuchokera kuzinthu zomwe zikubwera komanso kuyezetsa bwino zomwe zimatchedwa “ma cookie”, m’njira yofotokozedwa.
Molingana ndi miyezo yomwe yatchulidwa m’mawu oyambirira, kuyesa kwa mgwirizano kuyenera kuchitidwa pa kutentha kwa simenti, madzi ndi mpweya kuyambira 18 mpaka 21 °C. Mkhalidwewu ndi wofunikira poyesa zotsatira zake, chifukwa pamene kutentha kumachepa, nthawi yomangirira imawonjezeka, ndipo pamene kutentha kumawonjezeka, kumafupikitsa. Muzochitika zapadera, mwachitsanzo pakumanga misewu ya konkire, kuyesa kowonjezereka kumachitika m’chilimwe pa kutentha kuchokera 30 mpaka 35 °C.
Fanizo — kuyika ndi kusanja kosakaniza simenti.
Kuchepa ndi kutupa kwa simenti
Simenti slurry, wothira madzi ochulukirapo ofunikira pa konkriti ya nyumba zomangika, amawuma pokhazikitsa popanda kupanga mphamvu yayikulu pakulimbitsa komwe kumakwiriridwa. Kuchuluka kwa kuyanika kumadalira mtundu wa simenti, kuchuluka kwa madzi osakaniza, kutentha kwa konkire ndi zina.
Pogwiritsa ntchito simenti yatsopano pazinthu zosiyanasiyana zomangira, ming’alu ndi ming’alu zimawonedwa chifukwa chakuuma nyengo yotentha, yowuma komanso yamphepo. Mukayika, simenti imachepa ngati iuma, pamene simenti yomwe imasungidwa ndi chinyezi imafufuma.
Fanizo - ming’alu pamtunda wa simenti.
Mkhalidwe wa simenti panthawi yosungirako
Simenti zofunda
Amafunsidwa ngati simenti wotentha, mwachitsanzo kutentha kuchokera pa 30 kufika 80 °C, ndi koipa kuposa simenti kuchokera ku kutentha kuchokera 10 kufika 30 °C. Malinga ndi zomwe zidalembedwa poyambirira, kutentha kwa simentiyo sikukhala kofunikira kwenikweni ngati kugwiridwa mwaukadaulo, mwachitsanzo, ngati konkriti yatsopano imakhala ndi kutentha kwabwinobwino 25 °C.
Ndikofunikira kwambiri ngati simenti yotenthayo imachokera ku ma clinker atsopano omwe sanaziziritsidwe komanso osakalamba, kapena kutentha kwake kunapangidwa panthawi yopera. Panyumba zofunika, ndi bwino kugwiritsa ntchito simenti yomwe yatha kwa sabata imodzi.
Kufanana
Chinthu chofunikira kwambiri pamtundu wa simenti ndi kufanana kwa zinthu zomwe zidapangidwa kwa nthawi yayitali, ndikuwongolera pafupipafupi komanso pang’onopang’ono.
Kukhazikika kosungira
Kuyesa ndi simenti ya Portland, simenti yonyezimira ya Portland, kusungunula ndi simenti ya aluminate yawonetsa, pankhani ya simenti yamakono, kuti kusungirako kowuma mu silo ya simenti kapena m’matumba m’zipinda zowuma, komanso miyezi ingapo yosungira m’matumba apadera ndi zipinda zouma zouma, sizimakhudza kwambiri mphamvu ya simenti.
Ngati matumba asungidwa kwa nthawi yayitali ndipo simenti yaunjikana, zingakhale bwino kuyesa simentiyo pambuyo pake. Mukasunga m’mashedi, chitetezo ku mvula ndi mphepo ndikofunikira. Ngati kusungirako kotereku kumakhala kwa miyezi ingapo, matumbawo ayenera kutetezedwa kumbali zonse ndi mapepala okhala ndi denga kapena zinthu zofanana. Zikwama zamapepala za bituminous kapena matanki okhazikika amatchulidwa ngati njira zothetsera bwino.
Fanizo — nkhokwe zosungira simenti.