Ukubalwa Kwezidingo Zezinto Ezibalulekile Zezakhiwo Zekhonkrithi Eziqinisiwe
Ukubala izidingo zezinto zokwakha zekhonkrithi eqinisiwe kuyisinyathelo esibalulekile ekuhleleni nasekusetshenzisweni kwamaphrojekthi okwakha. Ukubala okunembile kuzothinta ukusebenza kahle kwezindleko, ukuthengwa ngesikhathi, kanye nekhwalithi yomsebenzi ensimini. Ukuntuleka kwezinto zokwakha kungabambezela umsebenzi, kuyilapho izinto ezengeziwe zibeka engcupheni yokwandisa izindleko, ukudala imfucuza, kanye nokwandisa isitoreji. Lesi sihloko sixoxa ngemiqondo eyisisekelo, izinyathelo zokubala, kanye nezibonelo zezindlela ezivamile zokubala izidingo zezinto zokwakha zekhonkrithi eqinisiwe.
1. Izingxenye zezinto ezisetshenziswa kukhonkolo eqinisiwe
Ngokuvamile, izakhiwo zekhonkrithi eziqinisiwe zakhiwa amaqembu amabili amakhulu ezinto zokwakha:
1. Ukhonkolo: ingxube yesamente, i-aggregate encane (isihlabathi), i-aggregate eqinile (itshe elicwebezelisiwe/elichotshoziwe), amanzi, kanye, uma kudingeka, nezingxube. Izidingo zekhonkolo zivame ukubalwa ngamayunithi evolumu (m³).
2. Insimbi eqinisayo: iqukethe ukuqinisa okuyinhloko, ukuqinisa okushefayo (izitibili/izindilinga), kanye nokuqinisa kokusabalalisa noma ukuqinisa ukuncishiswa. Izidingo zensimbi zibalwa ngamayunithi esisindo (kg noma amathani) kanye nobude (m).
Ngaphezu kwalokho, kunezinto ezisekelayo ezifana nomsebenzi wokwakha (ukhuni, ipulangwe, izinhlobo zensimbi), ucingo olugobayo, ama-spacer, kanye ne-curing compound. Kodwa-ke, ukugxila okuyinhloko kokubala izinto zokwakha zekhonkrithi eqinisiwe ngokuvamile kuvame ukubalwa komthamo wekhonkrithi kanye nesisindo sensimbi eqinisayo.
2. Izimiso eziyisisekelo zokubala ivolumu yokhonkolo
Ukubalwa kwevolumu ekhonkolo ngokuyisisekelo kulandela ifomula yevolumu yejometri yezinto zesakhiwo. Ezinye izinto ezivamile ezibalwe yilezi:
– Islabhu: Umthamo = ubude × ububanzi × ubukhulu
– Umshayo: Umthamo = ubude × ububanzi × ukuphakama (noma ubukhulu be-beam obuhlanganisa izingxenye)
– Ikholomu: Umthamo = indawo enqamulayo × ukuphakama
– Isisekelo sesisekelo: Umthamo = ubude × ububanzi × ubukhulu (noma ukuma kwe-trapezoidal/izitebhisi ngokwedizayini)
Uma umthamo wekhonkrithi usunqunyiwe, abahleli bavame ukwengeza isici sokuchitha noma ukubekezelela insimu. Inani lincike ebunzimeni bomsebenzi kanye nendlela yokubumba, kodwa ngokuvamile licishe libe ngu-2–5% womsebenzi ohlelekile nolawulwayo futhi lingaba phezulu uma izimo zensimu zingaphansi kokufanele.
Isibonelo esifushane
Isibonelo, i-floor slab enobukhulu obungu-10 m × 8 m enobukhulu obungu-0,12 m:
– Umthamo = 10 × 8 × 0,12 = 9,6 m³
Uma imfucuza ingu-3%:
– Umthamo womklamo = 9,6 × 1,03 = 9,888 m³ ≈ 9,89 m³
3. Guqula ivolumu yekhonkrithi ibe yizidingo zezinto (usimende, isihlabathi, amatshe ayigugu, amanzi)
Ensimini, ukhonkolo ungatholakala ngezindlela ezimbili eziyinhloko:
1. Ikhonkrithi exutshwe ngomumo: izidingo zichazwe kalula ku-m³ ngokwekhwalithi (isb. K-250, fc' 20 MPa, njalo njalo).
2. Ukhonkolo oxutshwe endaweni (oxutshwe endaweni): umthamo wekhonkolo udinga ukuhlukanisa phakathi kwezidingo zezinto zokwakha.
Ngokuxutshwa kwendawo, izidingo zezinto zincike ekwakhiweni kwengxube. Indlela elula ivame ukusebenzisa ithebula lokwakheka nge-1 m³ yekhonkrithi. Njengesiqondiso esijwayelekile (amanani angahluka kuye ngezindinganiso, izinto zokwakha, kanye nezinhloso zekhwalithi), izidingo nge-1 m³ yekhonkrithi yezinga eliphakathi zingase zibe kuhlu olulandelayo:
– Usimende: 300–400 kg
– Isihlabathi: 0,45–0,55 m³
– Ugwadule: 0,70–0,85 m³
– Amanzi: 160–210 amalitha
Ngenxa yokwehluka okuphawulekayo, kungcono ukusebenzisa ifomula yokuxuba imisebenzi noma umklamo wokuxuba elebhu. Kodwa-ke, ezilinganisweni zesabelomali sokuqala (i-RAB), indlela yethebula ivame ukusetshenziswa.
Umfanekiso wendlela yokwenza lokhu
Uma kusetshenziswa u-350 kg wesamente, u-0,5 m³ wesihlabathi, u-0,8 m³ wetshe eliyigugu, amalitha angu-180 amanzi ku-1 m³ yekhonkrithi, khona-ke ku-9,89 m³:
– Usimende = 9,89 × 350 = 3.461,5 kg ≈ 3,46 amathani (≈ 69 zak @50 kg)
– Isihlabathi = 9,89 × 0,5 = 4,945 m³
– Itshe eliyitshe = 9,89 × 0,8 = 7,912 m³
– Amanzi = 9,89 × 180 = 1.780,2 amalitha
Engeza izinto ezilahliwe uma kudingeka, ikakhulukazi isihlabathi kanye nohlaza (isib. 5–10%) ngenxa yokuphathwa kanye nokulahlekelwa ensimini.
4. Ukubalwa kwezidingo zensimbi yokuqinisa
Ngokungafani nokhonkolo osekelwe kumthamo, insimbi yokuqinisa ibalwa kusukela ku:
– inani leziqu,
– ubude ngenduku ngayinye,
- ububanzi bokuqinisa,
– isisindo ngemitha (kg/m).
4.1 Isisindo sokuqinisa ngemitha ngayinye
Isisindo esiqondile sensimbi ngokuvamile sicatshangwa ukuthi singama-7.850 kg/m³. Empeleni, isisindo esilinganiselwe sokuqinisa ngemitha singabalwa kusetshenziswa ifomula elandelayo:
Isisindo (kg/m) = 0,006165 × d²
d ku-mm.
Isibonelo:
– D10: 0,006165 × 10² = 0,6165 kg/m
– D13: 0,006165 × 13² = 1,042 kg/m
– D16: 0,006165 × 16² = 1,579 kg/m
– D19: 0,006165 × 19² = 2,224 kg/m
Leli nani liseduze nethebula elijwayelekile elivame ukusetshenziswa ngabalinganisi.
4.2 Izinyathelo zokubala izidingo zokuqinisa
1. Thola isithombe sesakhiwo: ububanzi, inombolo, isikhala, kanye nobude be-anchorage noma i-lap splice.
2. Bala ubude bokuqinisa obuphelele ngokusekelwe kubukhulu bezinto bese ufaka:
– ubude be-hook (i-hook) uma bukhona,
– ubude bokusatshalaliswa,
– ubude bokuhlangana kwamalunga,
– okungeziwe kokugoba.
3. Bala ubude obuphelele = inani lezinduku × ubude ngenduku ngayinye.
4. Ukuguqulwa kube yisisindo = ubude obuphelele × isisindo ngemitha.
5. Faka imfucuza (ngokuvamile 3–7%) yezingcezu nezingcezu.
Umqondo wesibonelo sebhulokhi
Isibonelo, ugongolo oluyimitha eyi-6 ubude lunokuqina okuyisisekelo okuqhubekayo kwe-4D16. Ake sithi ibha ngayinye idinga ukuthuthukiswa okwengeziwe okungu-0,4 m ekugcineni ngakunye (lokhu kwenzelwa izinjongo zokubonisa kuphela; amanani angempela angaphansi kwezidingo zomklamo).
– Ubude ngenduku = 6 + 0,4 + 0,4 = 6,8 m
– Ubude obuphelele = 4 × 6,8 = 27,2 m
– Isisindo D16 = 1,579 kg/m
– Isisindo esiphelele = 27,2 × 1,579 = 42,95 kg
Kuma-stirrup, ukubalwa kuvame ukuba:
– thola inani lama-stirrup = (ubude/isikhala esisebenzayo) + 1,
– bala ubude be-stirrup eyodwa = i-net circumference + ama-hook engeziwe,
– phindaphinda, bese uguqula ngesisindo ngemitha.
5. Izinto ezivame ukulibaleka ekulinganisweni
Ukuze kubalwe izidingo zezinto ezibonakalayo ngokunemba kakhudlwana, izici ezilandelayo zidinga ukucatshangelwa:
1. Ubukhulu besembozo sekhonkrithi buthinta ubukhulu obucacile be-stirrups kanye nobude obusebenzayo bokuqinisa.
2. Ubude bokusatshalaliswa kanye namajoyinti ethangeni kungandisa ukusetshenziswa kwensimbi kakhulu, ikakhulukazi ezintweni ezinde.
3. Umehluko ngobude bebha yefektri ejwayelekile (ngokuvamile amamitha ayi-12). Ukusika kusuka kubha eyi-12 m kuphumela ezingcoleni ezingasetshenziswa ngaso sonke isikhathi.
4. Izinguquko ekwakhiweni kwensimu (umdwebo wesitolo) njengokushintsha izikhala, izinguquko emininingwaneni yokuxhumana, noma isidingo sokuqinisa okwengeziwe.
5. Ikhwalithi yendlela yokwenza ifomu kanye nokukhipha imfucuza ithinta imfucuza yekhonkrithi (ukuchitheka, ukuvuza, njll.).
6. Uhlobo lokuqinisa (olungenalutho/olunentambo) kanye nezimo zokugoba ezithinta imininingwane yobude be-hook.
6. Izindlela ezisebenzayo: ukuphinda usebenzise kanye nesheduli yokugoba imigoqo (BBS)
Kumaphrojekthi ahlelwe kahle, izidingo zokuqinisa zibalwa kusetshenziswa i-Bar Bending Schedule (BBS), okuluhlu lwezinto zokuqinisa eziqukethe:
- ibhakhodi,
- isimo,
– ububanzi,
– ubude bokusika,
- inani,
– ubude obuphelele,
– isisindo esiphelele.
Nge-BBS, ukuthengwa kwensimbi kuba nembile kakhudlwana, okwenza kube lula ukwenziwa nokunciphisa imfucuza. Ngokhonkolo, ukufinyezwa komthamo ngesakhi ngasinye (amakholomu, imishayo, ama-slab, izitebhisi) kuvame ukuhlanganiswa ngesitezi ngasinye noma ngendawo ngayinye yokukhipha ukuze kuhambisane nochungechunge lokukhipha.
7. Isiphetho
Ukubala izidingo zezinto zokwakha zekhonkrithi eziqinisiwe kusekelwe ezintweni ezimbili: ivolumu yekhonkrithi kanye nesisindo sensimbi esiqinisiwe. Ivolumu yekhonkrithi ibalwa kusukela ezintweni zejometri futhi kunezelwa isici sokuchitha esifanele. Okwamanje, izidingo zokuqinisa zibalwa kusukela kumidwebo yesakhiwo enemininingwane (inombolo, ububanzi, isikhala, kanye nemininingwane yokuxhumanisa) bese iguqulwa ibe yisisindo kusetshenziswa isisindo ngemitha. Ukuze kwandiswe ukunemba nokunciphisa imfucuza, ukusetshenziswa kwe-BBS kokuqinisa kanye nokuphindaphinda kwevolumu ngendawo ngayinye yokuphonsa kunconywa kakhulu. Ezigabeni zokuqala, izilinganiso ezingahleliwe zingasebenzisa indlela yethebula, kodwa njengezindlela zokuqalisa, izibalo kumele zibhekisele kumidwebo yokugcina yokusebenza kanye nemininingwane yokuhlela ukuqinisekisa ukuthengwa kwezinto ezinembile kakhudlwana, iphrojekthi esebenza kahle kakhudlwana, kanye nokugcina ikhwalithi yesakhiwo.
