Kudzivirira simbi yekusimbisa kubva pakuora
Maererano neEurocodes yanhasi, ukobvu hushoma hweprotective concrete cover (cnom) hwakarongwa. Ukobvu hwakadaro hwekongiri ndicho chinhambwe chidiki kubva pamusoro wekunze wechinhu chekongiri yakasimbiswa kusvika kusimbi yekutanga. Pazvinhu zvemitsara izvozvo ndicho stirrup, uye pazvinhu zvepamusoro ndicho kusimbiswa kwepasi kwenguva refu. Nominal protective cover inotsanangurwa se: cnom = cmin + Δcdev
cmin ndiyo inokosha shoma inodiwa yedziviriro layer, kukosha kwayo kunoenderana nemamiriro ekunamatira kwekongiri nesimbi yekusimbisa, mamiriro enzvimbo, kupfekedzwa kwesimbi yekusimbisa, nezvimwe. Δcdev kukosha kunomirira kutsauka mukuitwa. Zvichienderana nekirasi yekusangana kwenhengo ye reinforced concrete pane kukosha kwakasiyana kwe nominal protective layer; kazhinji inowira kubva pa2,5 cm kusvika pa3,5 cm. Panzvimbo dzenheyo zvinotorwa kuti iri 5cm.
Maitiro e simende mortar nekongiri pakudziya nekutonhora kazhinji
Simba rebeton nyowani rinogona kuwedzerwa nekukurumidza nokudziyiswa zvishoma nezvishoma nemweya unopisa kana nekuiisa mumvura inodziyiswa zvishoma nezvishoma, vozotevera kutonhodza zvinyoronyoro. Nenzira iyi, mushure mezuva rimwe chete rekuita, masimba anowanikwa ayo muhurongwa hwakajairwa anowanikwa mushure memavhiki akati wandei. Chiyero chemhedzisiro chinoenderana nesimende uye mhando yeaggregate, asi nebhetani risina mafuta panowanikwa mhedzisiro iri nani zvikuru kupfuura nebhetani rine mafuta.
Kana kupisa nekutonhodza zvikaitwa mukati memiganhu yakakura, muchinhu chekongiri pachava nekushushikana kukuru kana kupisa nekutonhodza zvikaitwa nekukurumidza. Mumamiriro akadaro, uye zvikuru kana zvichidzokororwa kazhinji, zvinofanira kufungidzirwa kutsemuka kunobva kunze kuchipinda mukati zvichikanganisa hunhu hwemakanika hwekongiri. Pano simenti dzakasiyana dzinozvibata nenzira dzakasiyana, ndosaka pakushandiswa kwepraktiki kuchikurudzirwa kusarudza simenti nokungwarira.
Kupfuura kwekupisa mukongiri
Chiyero chekufambisa kupisa kwekongiri chinoenderana nehunhu hweaggregates necement, nehuwandu hwecement, huwandu hwemvura yekusanganisa, hunyoro hwekongiri, pamwe nekukwirira kwetembiricha. Pakuyedzwa nemaplate ane ukobvu hwe10 cm uye nekongiri yakaomeswa zvikuru, chiyero chekufambisa kupisa λ chakawanikwa kuva 1,163 W/mK pa10 oC, uye nemaplate ekongiri yakagara mumvura chinosvika 2,326 W/mK. Maplate akakora aipa ma coefficient ekufambisa kupisa akakwirira; kukosha kwepamusoro kwakanga kuri 2,38 W/mK.
Kuwedzera kwekongiri pakupisa
Kuwedzera zvikuru kunoenderana neagregati, vozoti nehunyorova hwebetoni, uyezve necimenti pachayo. Miganhu inozivikanwa kusvika zvino pa 0 kusvika 40 oC inenge 6 kusvika 13*10-6 m/m pa degree rega rega.
Kusimba pakuremerwa kunodzokororwa kazhinji
1. Simba rekudzvanya pakuneta. Pfungwa yesimba pakuneta yashandiswa pano muchirevo chakajairika; pakushandiswa kwehunyanzvi zvinofanira kugara zvichitaurwa masimba pakuneta (kudzvanya, kudhonza, kudzvanya nekudhonza zvichichinjana, kukotama, kucheka, kucheka kwakachena, kukotama kwebuckling) pamwe nenzira yekutakura mutoro (kungofamba zvinyoronyoro, kungogara kuchiitika, chikamu chiri chinyoronyoro uye chikamu chakamira).
Simba rekumanikidza pakuneta nekuda kwemutoro wakadzikama: zvinotarisirwa kuti kusimba kumutoro wenguva refu kuve kungangoita ¾ yesimba rinoonekwa pakuongorora kwakajairwa nekumanikidza.
Simba rekudzvanya pakuneta nekuda kwemitoro inodzokororwa (simba rekutanga re dynamic): simba rekutanga rekudzvanya re dynamic remapfumo ekongiri emarudzi akasiyana, uye kunyanya ane huwandu hwakasiyana hwesimende uye magranulation akasiyana, zvakaratidza kuti rinova kana kuti haripfuuriri 0,5 yesimba reprism pakuremerwa kwakajairika kusvika pakutyoka. Panguva iyi kwakaitwa 260 dzekutakura muminiti; huwandu hwese hwematenderedzwa hwakayerwa simba iri re dynamic hwaiva mamiriyoni maviri. Nekuwedzera kwenhamba yematenderedzwa paminiti (zvakaedzwa ne 10 kusvika 450 matenderedzwa paminiti), nhamba yekudzokororwa yaikonzera kutyoka yakawedzerawo.
Kusimba pakudzvanywa pakuneta kunokonzerwa nekushanda pamwe chete kwemitoro yakanyarara neino dzokororwa: Kana mitoro yakanyarara yawedzerwa kumitoro inodzokororwa, ipapo pakuwedzera kwemitoro yakanyarara kukosha kweamplitude yemitoro inodzokororwa, iyo yaizodzorwa kaviri miriyoni, kwakaderera. Semuenzaniso, fig. 1 rinoratidza kuti amplitudes yemitoro inodzokororwa S yaiva:
- pakuremerwa kwakadzikama nokuda kwe σu = 6 kg/cm2 S = 109 kg/cm2
- pakuremedzwa kwakadzikama pa σu = 118 kg/cm2 S = 39 kg/cm2
- pamutoro wakanyarara nokuda kwe σu = 157 kg/cm2 S = 8 kg/cm2
Muf. 1
Fig. 2
2. Kusimba kwekupeta kwekongiri pakuneta. Ongororo dzakaratidzwa pamuf. 2 pamatanda aichengetwa nguva dzose ari mumamiriro emvura, dzakaratidza, pamutoro wekutanga wedhinha, kuti kusimba kwekupeta pakuneta kuri 28 kg/cm2, nepo kusimba kwekupeta kwakajairika kwaive 53 kg/cm2, izvo zvinoenderana nechiyero 0,53.
Betoni yakareruka
Concrete yakareruka (kongiri ine uremu huri pasi pe 18 kN/m3) inowanikwa nekushandisa maaggregate akareruka, ane mapore akaita se: pumice, slag kubva mumafurnesi makuru, boiler slag, uyezve nekushandisa morta inobva mujecha rechisikigo kana rekugadzira nefurawa ine zvinowedzerwa zvinoburitsa gasi panguva yekugadzira morta (gas concrete) kana zvinokonzera furo mumorta (foam concrete).
Kongiri yakareruka, pakati pezvimwe zvinhu, inoshandiswa zvikuru mukugadzira mabhuroko ekuvaka nemaplate epumice emadziro nedenga; kana yakaoma haifambisi kupisa zvakanaka; kusimba kwayo kuri pakati, asi inogadzirika nyore, zvekuti mabhuroko akareruka emadziro anotakura mutoro wezvivako zvevanhu anogona kugadzirwa nechivimbo.
Semushonga wokukonzera magasi mukongiri ine gasi inoshandiswa upfu hwearuminiyamu. Zvichienderana nehuwandu hwezvimwe zvinongedzo pamwe nemamwe mamiriro, inowanikwa zvinhu zvine maporosi akawanda kana mashoma, huremu hwayo iri pakaoma huri paanenge 3 kN/m3 zvichikwira.
1. Uremu hwevhoriyamu hwekonkireti yakareruka. Nepumice yemusikirwo zvinogona kuvimbiswa uremu hwevhoriyamu – zvichireva muchimiro chakaomeswa pa105 oC – kutangira pa7 kN/m3 zvichikwira, pamwe nesimba rekumanikidza re2 MPa. Uremu hwevhoriyamu hunotarisirwa hunenge huchingova huwandu hweaggregate nesimende zviri muchimiro chakadururwa. Konkreti yegasi ine uremu hwevhoriyamu hunodarika 8 kN/m3 kazhinji haina kukodzera nehunyanzvi.
2. Kusimba kwekudzvanywa kwekongiri yakareruka. Nokongiri inozadzwa inogona kuwanikwa, pasina matanho akakosha, masimba e8 MPa, uye nejecha rematombo kunyange kusvika ku12 MPa. Ongororo dzenguva dzose dzekukodzera dzinodiwa. Kongiri ine mapores (gas concrete uye foam concrete) inokodzera madziro anotakura chete mushure mekuoma pasi pekumanikidzwa kwemhepo. Nezvinhu zvakasvibirira zvakakodzera, zvinogona kuvimbiswa uremu hwevhoriyamu hwe6 kN/m3 uye simba rekudzvanywa re5 MPa.
3. Simba rekukotama rebetoni yakareruka. Hukama pakati pesimba rekukotama nesimba rekumanikidza hwakaratidza mukati mezvinodiwa zvinoshanda kuva hwakakura zvichienzaniswa, uye sezvo masimba achiwedzera hukama uhu hunoderera.
4. Chiyero chekudzikira kwekongiri yakareruka. Chiyero chekudzikira chinonyanya kutsamira pakusimba kweaggregate, pamwe nehuwandu hwechisanganiswa checement yakasimba; kudzikira kwekongiri yakareruka kukuru kupfuura kudzikira kwekongiri yematombo madiki. Kongiri yakagadzirwa kubva pamadongo ezvidhinha yakaratidza mukati megore rimwe chiyero chese chekudzikira chinosvika 0,65 mm/m. Zvikamu zvichangobva kuunzwa zvepumice yepanyama, mukati memwedzi 14 m, zvakadzikira nezve 0,8 mm/m. Miedzo yekongiri yegasi nekongiri ine furo yaikwasha mumhepo yakaratidza kudzikira kukuru zvikuru, kunyange kupfuura 2 mm/m. Hatifaniri kukanganwa kuti kongiri yose kana yanyoroveswa nemvura yemvura uye chando chanyunguduka inozvimba, uye pakuzooma inodzikira zvakare.
Fig. 3
5. Coefficient of thermal conductivity. Coef. yekupfuurisa kupisa inoderera pamwe nekurema kwevhoriyamu, uye kana mamiriro ose ari mamwe chete inova diki zvikuru sezvo maburi ayo emhepo ari madiki uye akagoverwa zvakaenzana. Pakongiri yakazara nemhepo yakaoma, kukosha kwaiva (λ = 0,4625 pa 9 kN/m3; λ = 0,58 – 0,7 pa 12 kN/m3; λ = 0,81 – 1,05 pa 16 kN/m3). Kune gas concrete yakaoma nemhepo, data rinopiwa nefig. 3.
CHERECHEDZO:
- 0,1 kcal/mhoC = 0,1163 W/mK
- 0,1 kg/dm3 = 100 kg/m3 = 1 kN/m3