Ukusebenzisa Imineral Powders Ukuvutha Umsebenzi Wokwakha Kwemifula?

Kungani Umsebenzi Wokwakha Kwemifula Uyisisekelo — Ngaphezu Kwezifundo Zokuphela

Kwizinkulu zokwakha ngokwesibonelo, umsebenzi wokusebenza uyisisho esingaphezu kwezimilingo zokubhala isibonelo. Uyahlawula ukuthi inkambo entsha iyakwenzani ukufolowa, ukugcina i-formwork, nokubhala amasiko okukhanya ngaphandle kokuphakanyiswa noma kokuvula. Nangona isibonelo sokubhala isibonelo sivumela ukuthola isibonelo sokuhlelwa ngokusheshayo, akakwazi ukuthola isibonelo sokurhewolo yonke—ukusinda kwesibonelo, ukuchitha kwesibonelo sokuhlelwa, nokuthixotropi—okuyihlawulela ukusebenza kwesibonelo kwezindawo zokusebenza. Kumaqondiso okukhanya kwezindawo ezide, ukuthumela kwezindawo eziphakade, nokukhanya kwezindawo eziphakade kwezamasiko, ukubhekana nesibonelo sokubhala kuphela kungabonakala njengokuthi kuyisibonelo esingavumelekile: inkambo enesibonelo esivumekile singaphakanyiswa futhi ngezimilo noma sithola ukukhanya ngaphandle kokuthumela kwezilayini zokuthumela. Abaqondiso abasekelwe manje bafaka isibonelo sokubhala nesibonelo sokufolowa kwezitayela noma isibonelo se-V-funnel kwezinkambo ezingakwazi ukuzincongca noma ezingakwazi ukusebenza kahle. Ngaphezu kwekufolowa kwesibonelo, ukubeka isibonelo sokusebenza kuyisibonelo esibalulekile—ukuphela kwebhala kusuka kwezindawo zokuthumela kungazama ukuthi kubhekane nezinkinga zokubhala noma izihlangothi ezingavumelekile, okuyihlawulela ngqo ubunzima bezinkambo. Amaphowdha wezinkambo ayisiza ekubeni kubhekane nalokhu ngokuthintela ukuphakanyiswa kwamashilongo, ukunciphisa ukuthanda kwezibhamu, nokuhlalisa inkambo, okwenza kubo bayingcono kakhulu ukufika emsebenzini wokwakha inkambo eyodwa, eyodwa, nokubaluleka kakhulu kwezinkambo ezifana nezibonelo esingaphezu kwezibonelo esinye sokubhala.

Amaphutha Amashumi Okuphakathi Kwemvelo Yokubeka Emasisweni Sokubeka Kwemvelo

Umba Wokubeka: Isifundo Se-Clas F Noma Se-Clas C Kusukela Ku-Flow Retention Nase-Cohesion Kwemvelo Yokubeka

Ukukhetha isifundo se-umbha wokubeka kuyabangela ukuguqula kwe-rheological phakathi kwe-flow retention nase-mixture cohesion. Umba wokubeka we-Clas F—okungu-cao kakhulu futhi unamaphutha amashumi amagcwele okuphakathi kwemvelo—kusebenza njengomphakathi wokuphakathi okunciphisa ukugxilana kwezinto zokuphakathi, kuvumela ukuthi isumpu liyadlala ngaphezu kweziminyaka eziyisithupha ngaphandle kokuthi libe lichitha ngokushesha, futhi libe lichitha ngokushesha ngaphandle kokuthi libe lichitha ngokushesha. Ngaphakathi kwezinye izindaba, umba wokubeka we-Clas C unamandla we-CaO angaphezulu, okungaba yindlela yokubegina ukubegina kwezinsuku ezincane. Nakuba kungaba yindlela yokubegina kwezinsuku ezincane, kungaba yindlela yokubegina kwezinsuku ezincane, kungaba yindlela yokubegina kwezinsuku ezincane, kungaba yindlela yokubegina kwezinsuku ezincane. Ngokwempikiswano, umba wokubeka we-Clas F uyasebenzisa kakhulu kuma-pumping angaphezulu kuma-distant noma kuma-hot-weather placements lapho ukudlala kwe-flow kuyisisekelo esikhulu; umba wokubeka we-Clas C ungasebenzisa kuphela lapho ukubegina kwezinsuku ezincane kuyatholakala—futhi kuphela lapho ukudlala kwe-sumpu kuyamaniswa ngokushesha nge-superplasticizers.

Ukuthakazelwa kwe-Silica Fume ne-Limestone Powder: Ukuphakamisa Kwemithambo vs. Ukuthakazelwa Kwemithambo Kwe-Concrete Building

I-Silica fume ne-limestone powder zihlela ukusebenza ngokufanayo ngemikhombobo eyodwa: ukuphakamisa kwemithambo kanye nokuthakazelwa kwemithambo kwe-hydration. I-Silica fume—yindlela yokuqhubeka kahle yomthambo wokugcina okuphakeme kakhulu, ene-isiqinisekiso sesiphondo se-15–30 m²/g—iyathakazela imikhumbi emincane kakhulu phakathi kwezinkulungwane zocement, iyaphakamisa ukuphakamisa kwezinkulungwane futhi iyanciphisa ukuthakazelwa. Kodwa, isiphondo esiphezulu sakho sibiza amanzi angaphezu kwezinkinga, okubizwa ngokuthi kuyadingeka ukusebenzisa amanzi amaningi okukhupha amanzi ukuze ubuyise ukusebenza. I-Limestone powder, engaqhubeki kahle kakhulu kodwa iphakeme kakhulu kanti, inika izindawo zokuthakazelwa ezihambisana nokuthakazelwa kwe-silicate kusuku lokuqala—kubuyisa ukusebenza kwe-paste futhi ukubuyisa ukuthintana kwayo, ngokunciphisa ukuthakazelwa kwezinhlobo. Isibonelo sokuhlanganiswa—okusho kakhulu kukuba kune-5–8% ya-silica fume nesibonelo se-10–15% ya-limestone powder—sivumela umkhumbi ophakeme, obulungile, ne-okuphakamisa kwezinkulungwane, okunconywa kakhulu kuma-concrete building akhulu.

GGBS: Ukulandela Ukugcina Kwemithambo Ne-Setting Time Kuma-Thresholds Okuphambili

I-Ground granulated blast-furnace slag (GGBS) isebenza ngokuthuthukisa ukugcina kwemithambo futhi isondeza isikhathi sokusebenza—kepha kuphela kumathreshhold okuncane wokufaka. Ngama-30–50% yokufakwa ngomkhawulo wamandla, i-GGBS isebenza ngokunika umthwalo osheshayo nokubheka phansi okungafani noma yikuphi, okunciphisa ukugqibela kwezinto ezihlukene futhi isenhleza ukuzimela. Ngaphezu kwe-50%, ukusebenza kwakho okungaphansi kokuhlanganiswa kwenziwa ngamandla kungasondela isikhathi sokugqibela kusasa ngama-2–4 amahora, ikakhulu emizimini emibi—lokhu kusondela ukuthuthukisa ukuthuthukisa kwezindawo eziphakeme kodwa kungabangela ukuthi izinkampani zisobala uma akusondelwanga. Isikhathi esihle sokufaka siphakathi kwe-35% ne-45% kubantu abasebenzisa i-concrete ebukhaya, lapho ukuthuthukisa kwemithambo nokusondela isikhathi sokusebenza kubalwa ngokulingana nesikhathi sokugqibela esihle—uma isikhathi semandla sibephezulu kwe-10 °C.

Izindlela Zokusebenzisa Amaphutha Amanzi Emadwaleni Ekubeni I-Concrete Ebukhaya

Iziratio Zokufaka Ezihle Futhi Ukubhalwa Kwamabili Ukuze Ukwakhiwa Kwesikhathi Esinye Noma Ukuphakama Kwesikhathi Sokusebenza

Ukuhlanganisa okufanayo kufuna ukuthi isilika seminyaka sikhululekile ngokupheleleyo nokuthi izinhlobo zokuhlanganisa zihlanganiswe ngokuvamile. Ukubuyisela ama-20–30% amacimento ngeminyaka yaseNingizimu Afrika (Class F fly ash) kubiza umkhawulo wokudlula ngaphandle kokuthi kwenziwe ngokushesha; ukugcina isilika seminyaka yesilica (silica fume) ngezinsukwane ezingu-8% kungavikela ukuthi kubhekwe ngokushesha ngokuphakeme kwesilika. Ukulangana ngokulandela umphumela: funa isilika seminyaka yelimestone emva amandla amahlanu aqala ukuhlakazeka kakhulu, emva kwalokho funda isilika seminyaka yaseNingizimu Afrika ngokulandela ukuze usuke ukuthi kuzwa ngokushesha. Lokhu kulandela kusiza ukuthi isilika sikhululekile ngokupheleleyo ngokuthi izinye zezinye zisobala phakathi kweminyaka yamacimento, kubeka ubuncinane bokuhlakazeka phakathi kweminyaka. Amathuba asebhaleni abonisa ukuthi isilika seminyaka yaseNingizimu Afrika nezinsukwane ezingu-15% nezinsukwane ezingu-5% zelimestone zibiza umkhawulo wokudlula ngokupheleleyo ngamaminithi amashumi eli-40 [1]. Sicela uvumeleke ngokupheleleyo izilika zokuhlanganisa ngeminyaka yasekhaya—ukuthi kunezinkambo zokuthi kubhekwe ngokushesha kungabonisa ukuthi kubhekwe ngokushesha—futhi uvumelise ukuthi izilika zokuhlanganisa zihlanganiswe ngokupheleleyo ngokusebenzisa i-Marsh funnel ukuze ubone ukuthi kubhekwe ngokushesha.

Ukuboniswa Kwempilo Yomlando: Isifundo Sase-Tanjong Pagar Tower — Isilika Seminyaka YaseNingizimu Afrika Ngamashumi Amabili Namashumi Amashumi Ayisibili + Isilika Seminyaka Yelimestone Ngamashumi Ayisibili Sobiza Umkhawulo Wokudlula Ngamashumi Amashumi Ayisigqama

Umbhokhwe we-Tanjong Pagar Tower e-Singapore yavakalisa ukuthi indlela yokusebenzisa amathambo amabili iyakhubeka njani ekupheleni kwemisebenzi yasezinsukwini. Ngokusebenzisa i-fly ash ngemiphumela yezinkampani eziyisigaba se-22% ne-powder yelimestone ngemiphumela yezinkampani eziyisigaba se-8% njengokugcina kwe-cement—futhi ukugcina isigaba se-water-binder esiyi-0.32—umthombo waphumelela ngokuthuthukiswa kwe-19% kwe-pumpability, okuchazwa njengokuphelelwa kwe-pressure ngomitha wokuphakama [2]. Izinto zokubhokhwa zidlula ngemiphumela yezinkampani eziyisigaba se-30%, isikhathi sokufaka sifela ngemiphumela yezinkampani eziyisigaba se-12%, futhi i-compressive strength yase-28-day yafika emisipilweni yayo ngemiphumela yezinkampani eziyisigaba se-55 MPa. Kusukela kuleli qembu, indlela yokubhala ngokulandela kuyasinda isikhathi esinye sokuphela ngokuhle futhi iyathuthukisa ukubambisana nokudlula. Le ndlela yayisetyenziswa kusukela kuma-projekthi amathathu e-high-rise emizini eyodwa—kuvumeka ukuthi kuyasebenza kanye noma kuyasebenza kuma-projekthi amaningi ukuze kuthuthukiswe umsindo wokwakha futhi ukuthuthukiswa kwe-quality yomphakathi wokuphakama.

Imibuzo Evame Ukubuzwa

Kungani ubuchwepheshe be-slump kuphela akakwazi ukubhekisa ukuthi umsebenzi uyasebenza njani?

Ukuqondisa ukuthi kubhekwe indawo yokugcina kuyisibonelo sokufana kuphela futhi akasikhi zizindawo zokuziphatha ngendlela yezinkulungwane njengezindawo zokuphuma, izinkulungwane zokugcina, nokuthi kuyisibonelo sokufana, okuzidingekile kakhulu kumsebenzi wokusebenza kwempilo, ikakhulu emaphakathini amaningi.

Izimali zokusebenzisa i-Class F fly ash kubhukisi lezinkulungwane zokwakha?

I-Class F fly ash iyabuyisa ukuthi isibonelo sokufana siyagcina ngokucindezela ukuthi izinkulungwane zihlukaniswe, iyadlula isibonelo sokufana, futhi iyahlela ukuthi izinkulungwane zihlanganise ngaphandle kokuthi zihlala kakhulu, okwenza ukuthi kuyisibonelo esihle kusukela kumaphakathi amaningi noma kumaphakathi aphakathi kwezinsuku ezinomkhovu.

I-silica fume ne-limestone powder zihlanganisa njani?

I-silica fume iyabuyisa ukuthi izinkulungwane zihlukaniswe futhi iyacindezela ukuthi amanzi ayadlula, kodwa iyabuyisa ukuthi amanzi ayadingeka, ngakho-ke i-limestone powder iyabuyisa ukuthi izinkulungwane zihlukaniswe futhi iyagcina ukuthi amanzi ayagcina. Ukuchazwa kwezimbili kwenza ukuthi kubhekwe indawo yezinkulungwane ephakeme futhi iyahlela ukuthi amanzi ayagcina.

I-dosage esihle kwe-GGBS yini?

Isiphakathi sesilinganiso sokusebenzisa i-GGBS sikhulu kakhulu phakathi kwe-35% ne-45% yemisa yamandla, esikhethekile isikhathi sokusebenza ngokupheleleyo futhi isikhathi sokubeka kusenziwa ngokupheleleyo, ikakhulukazi lapha isikhathi semoto yesilika sikhulu kune-10 °C.

Kungani amapowdha emithili angasebenza njengokuvimbela ukubeka kahle kanye nokuphazimula kokugcina?

Ukusebenzisa izindlela zokuhlanganisa ngokujwayelekile futhi izibalo zokufaka (isibonelo, ukufaka ipowdha yelimestone emva kokufaka amanzi kwanoma ukufaka i-fly ash ngokuphakeme) kusiza ekugcineni isikhathi sokusebenza ngokupheleleyo futhi ukuvimbela ukuguqula kahle kokugcina.

[1] ASTM C1877-23, Umsebenzi wokusebenzisa ipowdha yelimestone esilika .
[2] I-Singapore Building and Construction Authority (BCA), Isirhwebu sokusebenzisa isilika esiphakeme ngokwempilo , 2023.