Post Date:26,Dec,2022
1. Mvura-Kuderedza Concrete Admixtures
Misanganiswa inoderedza mvura zvinhu zvemakemikari izvo kana zvawedzerwa pakongiri zvinogona kugadzira kudonhera kunodiwa pachiyero chemvura-simende yakaderera pane yaanowanzo kugadzirwa.Mvura inoderedza misanganiswa inoshandiswa kuwana chaiyo kongiri simba uchishandisa yakaderera simende zvirimo.Zvepasi simende zvirimo zvinokonzeresa kuburitsa kwakadzika CO2 uye kushandiswa kwesimba pavhoriyamu yekongiri inogadzirwa.Nemhando iyi yekusanganiswa, zvivakwa zvekongiri zvinovandudzwa uye zvinobatsira kuisa kongiri pasi pemamiriro ezvinhu akaoma.Zvidzikisira zvemvura zvakashandiswa zvakanyanya mumadhizaini emabhiriji, pasi-inodonhera kongiri yakafukidzirwa, uye kupeta kongiri.Kufambira mberi munguva pfupi yapfuura mune admixture tekinoroji kwakatungamira mukugadzirwa kwepakati-renji yekuderedza mvura.
2. Concrete Admixtures: Superplasticizers
Chinangwa chikuru chekushandisa superplasticizers ndechekugadzira kongiri inoyerera ine kudonha kwakakwira muhupamhi hwemasendimita manomwe kusvika mapfumbamwe kuti ishandiswe mune zvakasimbiswa zvakanyanya zvivakwa uye mukuisa uko kubatanidzwa kwakakwana nekuzunguza hakugone kuwanikwa nyore.Imwe huru yekushandisa ndeyekugadzirwa kwekongiri yakasimba-yakasimba paw/c kubva pa0.3 kusvika 0.4.Zvakaonekwa kuti kune akawanda marudzi esimende, superplasticizer inovandudza kushanda kwekongiri.Rimwe dambudziko rakabatana nekushandisa yakakwira renji mvura inoderedza mukongiri kurasikirwa kwekudonha.Yepamusoro yekushanda kongiri ine superplasticizer inogona kugadzirwa neakanyanya kutonhora-thaw kuramba, asi zvemukati zvemhepo zvinofanirwa kuwedzerwa zvine chekuita nekongiri isina superplasticizer.
3. Concrete Admixtures: Set-Retarding
Set retarding kongiri admixtures anoshandiswa kunonoka kuita kwemakemikari kunoitika kana kongiri yatanga kugadzirisa.Aya marudzi ekongiri admixtures anowanzo shandiswa kuderedza mhedzisiro yekupisa kwakanyanya kunogona kuburitsa nekukurumidza kwekutanga kuseta kongiri.Set retarding admixtures inoshandiswa mukuvaka kongiri pavement, ichibvumira nguva yakawanda yekupedzisa kongiri pavement, kuderedza mari yekuwedzera yekuisa mutsva wekongiri batch chirimwa panzvimbo yebasa uye inobatsira kubvisa majoini anotonhora mukongiri.Retarders inogona kushandiswawo kuramba kutsemuka nekuda kweforoma deflection inogona kuitika kana horizontal slabs akaiswa muzvikamu.Mazhinji anodzoreredza anoshandawo seanoderedza mvura uye anogona kupinza mweya mukongiri
4. Concrete Admixtures: Air-Entraining Agent
Air intraining kongiri inogona kuwedzera kuomesa-kunyunguduka kwekongiri.Rudzi urwu rwemusanganiswa unoburitsa kongiri inoshanda kupfuura isina kudzidziswa kongiri uku ichideredza kubuda ropa uye kupatsanurwa kwekongiri nyowani.Kunatsiridza kupikisa kwekongiri kune yakanyanya chando chiito kana kuomesa / kunyungudika kutenderera.Zvimwe zvinobatsira kubva musanganiswa uyu ndezvi:
a.Kunyanya kupikisa kutenderera kwekunyorova uye kuomesa
b.High degree of workability
c.High degree of durability
Mafuro emhepo akapinzwa anoita sechivharo chemuviri kurwisa kutsemuka kunokonzerwa nekushushikana nekuda kwekuwedzera kwehuwandu hwemvura mukupisa kwechando.Mhepo inovaraidza admixtures inoenderana neanenge ese kongiri admixtures.Kazhinji pachikamu chimwe chete kubva muzana chemweya wakapinzwa, simba rekumanikidza richaderedzwa neanenge mashanu muzana.
5. Concrete Admixtures: Kuwedzera
Shrinkage-kuderedza kongiri admixtures inowedzerwa kune kongiri panguva yekutanga kusanganiswa.Rudzi urwu rwemusanganiswa runogona kuderedza kutanga uye kwenguva refu kuomesa shrinkage.Shrinkage kuderedza admixtures inogona kushandiswa mumamiriro ezvinhu apo shrinkage cracking inogona kutungamirira kumatambudziko ekugara kwenguva refu kana apo nhamba huru yezvibatanidza shrinkage zvisingadikanwi nokuda kwezvikonzero zvehupfumi kana zveunyanzvi.Shrinkage inoderedza misanganiswa inogona, mune dzimwe nguva, kuderedza kukura kwesimba pazera rekutanga uye gare gare.
6.Concrete Admixtures: Shrinkage Kuderedza
Shrinkage-inoderedza kongiri admixtures inowedzerwa kune kongiri panguva yekutanga kusanganiswa.Rudzi urwu rwemusanganiswa runogona kuderedza kutanga uye kwenguva refu kuomesa shrinkage.Shrinkage kuderedza admixtures inogona kushandiswa mumamiriro ezvinhu apo shrinkage cracking inogona kutungamirira kumatambudziko ekugara kwenguva refu kana apo nhamba huru yezvibatanidza shrinkage zvisingadikanwi nokuda kwezvikonzero zvehupfumi kana zveunyanzvi.Shrinkage inoderedza misanganiswa inogona, mune dzimwe nguva, kuderedza kukura kwesimba pazera rekutanga uye gare gare.
7. Concrete Admixtures: Corrosion-Inhibiting
Corrosion-inhibiting admixtures inowira mu specialty admixture category uye inoshandiswa kunonotsa kuora kwesimbi inosimbisa mukongiri.Corrosion inhibitors inogona kuderedza zvakanyanya mari yekuchengetedza yeakasimbiswa kongiri zvimiro mukati menguva yese yehupenyu hwesevhisi ye30 - 40 makore.Zvimwe zvakakosha zvinosanganiswa zvinosanganisira shrinkage-reducing admixtures uye alkali-silica reactivity inhibitors.Corrosion-inhibiting admixtures ine simba shoma pakusimba pazera rinotevera asi inogona kukurumidza kukura kwesimba rekutanga.Calcium nitrite based corrosion inhibitors inomhanyisa nguva yekumisikidza kwekongiri pamusoro pemhando yetembiricha yekurapa kunze kwekunge yagadzirwa ine set retarder yekumisa kukurumidza mhedzisiro.
Nguva yekutumira: Zvita-27-2022