Umhla wokuPoswa:14,Mar,2022

I-admixture ichazwa njengenye into ngaphandle kwamanzi, i-aggregates, i-hydraulic cementitious material okanye i-fiber reinforcement esetyenziswa njengesithako somxube we-cementitious ukuguqula iipropati zayo ezixubileyo, ukusetwa okanye ukuqina kwaye yongezwa kwibhetshi ngaphambi okanye ngexesha lokuxuba. .Njengoko kuphawuliwe kwiSigaba 1, i-chemical admixture idla ngokuchazwa ngakumbi njenge-nonpozzolanic (ayifuni i-calcium hydroxide ukuba isebenze) i-admixture ngendlela yolwelo, ukumiswa okanye ukuqiniswa kwamanzi.

Imixube yokunciphisa amanzi iphucula iplastiki yekhonkrithi (emanzi) kunye neempawu eziqinileyo, ngelixa imixube yokulawula iseti isetyenziswa kwikhonkrithi ibekwe kwaye igqityezelwe ngaphandle kwamaqondo obushushu afanelekileyo.Zombini, xa zisetyenziswe ngokufanelekileyo, zifak’ isandla kuqheliselo oluhle lokufundisa.Kwakhona, zombini i-admixtures kufuneka ihlangabezane neemfuno ze-ASTM C 494 (jonga iThebhile 1).

Imixube yokunciphisa amanzi

Izinciphisi zamanzi zenza oku: ukunciphisa umthamo wamanzi okuxuba afunekayo ukufumana ukuthotywa okunikiweyo.Oku kunokubangela ukunciphisa umlinganiselo we-cementitious wamanzi (w / c ratio), okhokelela ekunyukeni kwamandla kunye nekhonkrithi ehlala ixesha elide.

Ukunciphisa umlinganiselo we-w/c wekhonkrithi ichongiwe njengeyona nto ibalulekileyo ekwenzeni ikhonkrithi ehlala ixesha elide, ekumgangatho ophezulu.Ngakolunye uhlangothi, ngamanye amaxesha umxholo wesamente unokuthotywa ngelixa ugcina umlinganiselo wokuqala we-w / c ukunciphisa iindleko okanye ukushisa kwe-hydration yokuthululelwa kwekhonkrithi eninzi.

I-admixtures yokunciphisa amanzi nayo iyanciphisa ukuhlukana kunye nokuphucula ukuhamba kwekhonkrithi.Ke ngoko, ziqhele ukusetyenziswa kwizicelo zokumpompa ikhonkrithi ngokunjalo.

I-admixtures yokunciphisa amanzi ngokuqhelekileyo iwela kumaqela amathathu: i-low-, medium-and high-range.La maqela asekelwe kuluhlu lokunciphisa amanzi kwi-admixture.Ipesenti yokunciphisa amanzi inxulumene nomxube wokuqala wamanzi ofunekayo ukufumana ukuthotywa okunikiweyo (jonga kwiThebhile 2).

Ngelixa zonke izinciphisi zamanzi zinento efanayo, nganye inesicelo esifanelekileyo esisifanelekele kakhulu.Itheyibhile ye-3 ibonisa isishwankathelo seentlobo ezintathu zokunciphisa amanzi axutywayo, iindidi zabo zokunciphisa amanzi kunye nokusetyenziswa kwazo okuphambili.Impembelelo yabo kwi-air intrainment iya kuhluka ngokuxhomekeke kwi-chemistry.

Indlela abasebenza ngayo

Xa isamente idibana namanzi, iintlawuliso zombane ezingafaniyo kumphezulu wamasuntswana esamente zitsala enye kwenye, nto leyo ekhokelela ekungqubekeni okanye kumaqela amasuntswana.Inxalenye enhle yamanzi ifakwe kule nkqubo, ngaloo ndlela ikhokelela kumxube odibeneyo kunye nokunciphisa ukuhla.

Imixube yokunciphisa amanzi ngokuyimfuneko yenza ukuba imirhumo yomphezulu ingabi mandla kumasuntswana aqinileyo kwaye ibangela ukuba yonke imiphezulu ithwale njengentlawulo.Kuba amasuntswana aneentlawulo ezifanayo agxotha omnye komnye, anciphisa ukushukuma kwamasuntswana esamente kwaye avumele ukusasazwa ngcono.Bakwanciphisa i-viscosity ye-paste, okubangela ukuhla okukhulu.

Uluhlu lwesi-4 lubonisa ezinye zezinto eziqhelekileyo ezisetyenziselwa uluhlu ngalunye lwesinciphisi samanzi.Amanye amacandelo nawo adityaniswe ngokuxhomekeke kwimveliso kunye nomvelisi.Ezinye ii-admixtures zokunciphisa amanzi zineempembelelo zesibini okanye zidibaniswe ne-retarders okanye i-accelerators.