1. Imfuneko yokugcinwa kwamanzi
Zonke iintlobo zeziseko ezifuna udaka ekwakhiweni zinenqanaba elithile lokufunxa kwamanzi.Emva kokuba umaleko wesiseko ufunxa amanzi eludaka, ukwakhiwa kodaka kuya kuba mbi, kwaye kwiimeko ezinzima, izinto zesamente eludaka aziyi kugcwala ngokupheleleyo, okukhokelela kumandla aphantsi, ngakumbi amandla onxibelelwano phakathi kodaka oluqinileyo. kunye nomgangatho wesiseko, obangela ukuba udaka luqhekeke kwaye liwe.Ukuba udaka lokutyabeka lunomsebenzi ofanelekileyo wokugcinwa kwamanzi, alukwazi nje ukuphucula ngokufanelekileyo ukusebenza kokwakhiwa kodaka, kodwa lwenza ukuba amanzi omdaka afunxwe ngumaleko wesiseko kwaye aqinisekise ukuhanjiswa okwaneleyo kwesamente.
2. Iingxaki ngeendlela zemveli zokugcina amanzi
Isisombululo sendabuko kukunkcenkceshela isiseko, kodwa akunakwenzeka ukuqinisekisa ukuba isiseko sinomanzi ngokulinganayo.Ithagethi efanelekileyo ye-hydration ye-cement mortar kwisiseko kukuba imveliso ye-cement hydration ithatha amanzi kunye nesiseko, ingena kwisiseko, kwaye yenza "uqhagamshelwano oluphambili" olusebenzayo kunye nesiseko, ukuze kufezekiswe amandla afunekayo ebhondi.Ukunkcenkceshela ngokuthe ngqo kumphezulu wesiseko kuya kubangela ukusasazwa okunzulu ekufunxeni kwamanzi kwisiseko ngenxa yokungafani kobushushu, ixesha lokunkcenkceshela, kunye nokufana kwamanzi.Isiseko sinokufunxa okuncinci kwamanzi kwaye siya kuqhubeka nokufunxa amanzi kumdaka.Ngaphambi kokuba i-cement hydration iqhube, amanzi axutywe, achaphazela i-cement hydration kunye nokungena kweemveliso ze-hydration kwi-matrix;isiseko sinokufunxa okukhulu kwamanzi, kwaye amanzi kumdaka ageleza ukuya kwisiseko.Isantya semfuduko esiphakathi siyacotha, kwaye kwakhiwe umaleko otyebileyo wamanzi phakathi kodaka kunye ne-matrix, ekwachaphazela amandla ebhondi.Ngoko ke, ukusebenzisa indlela yokunkcenkceshela isiseko esiqhelekileyo akuyi kuphumelela kuphela ukusombulula ngokufanelekileyo ingxaki yokutshatyalaliswa kwamanzi aphezulu kwisiseko sodonga, kodwa kuya kuchaphazela amandla okubambisana phakathi kodaka kunye nesiseko, okubangela ukugoba kunye nokuqhekeka.
3. Iimfuno zodaka ezahlukeneyo zokugcina amanzi
Izinga logcino lwamanzi ekujoliswe kulo kwimveliso yodaka olutyatyekwayo olusetyenziswa kwindawo ethile nakwiindawo ezinobushushu obufanayo kunye neemeko zokufuma zicetywa ngezantsi.
①Udaka lwamanzi olufunxayo olusezantsi
I-substrates yokufunxa amanzi aphakamileyo emele ikhonkrithi efakwe emoyeni, kubandakanywa iibhodi ezahlukeneyo zokwahlula, iibhloko, njl., zineempawu zokufunxa amanzi amakhulu kunye nobude obude.Udaka lokutyabeka olusetyenziselwa olu hlobo lomaleko wesiseko kufuneka lube nomyinge wokugcinwa kwamanzi ongekho ngaphantsi kwama-88%.
②Udaka lwamanzi olufunxayo olusezantsi
I-substrates yokufunxa amanzi aphantsi amelwe yi-concrete-in-place-place, kubandakanywa iibhodi ze-polystyrene zokugquma udonga lwangaphandle, njl., zinento encinci yokufunxa amanzi.Udaka lokutyabeka olusetyenziselwa ezo substrates kufuneka lube nesantya sokugcina amanzi esingekho ngaphantsi kwama-88%.
③ Umaleko obhityileyo wokutyabeka udaka
Utyatyeko oluluqilima lubhekiselele kulwakhiwo lokutyabeka olunobukhulu obuphakathi kwe-3 ne-8 mm.Olu hlobo lokwakhiwa kokutyabeka kulula ukulahlekelwa ngumswakama ngenxa yomgangatho onqabileyo wokutyabeka, ochaphazela ukusebenza kunye namandla.Ngodaka olusetyenziselwa olu hlobo lokutyabeka, izinga lokugcinwa kwamanzi alikho ngaphantsi kwe-99%.
④Umaleko otyebileyo wokutyabeka udaka
Ukutyatyekwa okungqindilili kubhekiselele kulwakhiwo lokutyabeka apho ubukhulu bomaleko wokutyabeka omnye buphakathi kwe-8mm kunye ne-20mm.Olu hlobo lolwakhiwo lokutyabeka alulula ukuphulukana namanzi ngenxa yomgangatho ongqindilili wokutyabeka, ngoko ke izinga lokugcinwa kwamanzi odaka lokutyabeka akufanele libe ngaphantsi kwama-88%.
⑤Iputty enganyangekiyo ngamanzi
Iputty enganyangekiyo emanzini isetyenziswa njengesixhobo sokutyabeka esibhityileyo kakhulu, kwaye ubukhulu bokwakha ngokubanzi buphakathi kwe-1 kunye ne-2mm.Izinto ezinjalo zifuna iipropathi eziphezulu kakhulu zokugcina amanzi ukuqinisekisa ukusebenza kwazo kunye namandla ebhondi.Kwizinto ze-putty, izinga lokugcinwa kwamanzi akufanele libe ngaphantsi kwe-99%, kwaye izinga lokugcinwa kwamanzi kwi-putty kwiindonga zangaphandle kufuneka libe likhulu kunelo putty kwiindonga zangaphakathi.
4. Iindidi zezinto zokugcina amanzi
Iselulosi ether
1) Methyl cellulose ether (MC)
2) Hydroxypropyl Methyl Cellulose Ether (HPMC)
3) I-Hydroxyethyl cellulose ether (HEC)
4) Carboxymethyl cellulose ether (CMC)
5) Hydroxyethyl Methyl Cellulose Ether (HEMC)
Isitatshi ether
1) I-ether yesitatshi elungisiweyo
2) Gcoba iether
I-thickener yokugcina amanzi eminerali elungisiweyo (i-montmorillonite, i-bentonite, njl.)
Eyesihlanu, oku kulandelayo kugxininisa ekusebenzeni kwezinto ezahlukeneyo
1. Iselulosi ether
1.1 Isishwankathelo se-Cellulose Ether
I-ether ye-cellulose ligama eliqhelekileyo loluhlu lweemveliso ezenziwe ngokusabela kwe-alkali cellulose kunye ne-etherification agent phantsi kweemeko ezithile.Ii-ether ze-cellulose ezahlukeneyo zifunyenwe ngenxa yokuba i-alkali fiber ithathelwa indawo yi-etherification agents ezahlukeneyo.Ngokweempawu ze-ionization zamalungu ayo, i-cellulose ethers inokwahlulwa ibe ngamacandelo amabini: ionic, njenge-carboxymethyl cellulose (CMC), kunye ne-nonionic, njenge-methyl cellulose (MC).
Ngokweentlobo zezinto ezibambeleyo, i-cellulose ethers inokohlulwa ibe yi-monoethers, njenge-methyl cellulose ether (MC), kunye ne-ether exutyiweyo, njenge-hydroxyethyl carboxymethyl cellulose ether (HECMC).Ngokwezinyibilikisi ezahlukeneyo ezinyibilikayo, zinokwahlulwa zibe ziindidi ezimbini: i-soluble yamanzi kunye ne-organic solvent-soluble.
1.2 Iindidi eziphambili zeselulosi
I-Carboxymethylcellulose (CMC), isidanga esisebenzayo sokutshintshwa: 0.4-1.4;i-etherification agent, i-monooxyacetic acid;ukunyibilikisa isinyibilikisi, amanzi;
I-Carboxymethyl hydroxyethyl cellulose (CMHEC), iqondo elisebenzayo lokutshintshwa: 0.7-1.0;i-etherification agent, i-monooxyacetic acid, i-ethylene oxide;ukunyibilikisa isinyibilikisi, amanzi;
I-Methylcellulose (MC), isidanga esisebenzayo sokutshintshwa: 1.5-2.4;i-etherification agent, i-methyl chloride;ukunyibilikisa isinyibilikisi, amanzi;
I-Hydroxyethyl cellulose (HEC), iqondo elisebenzayo lokutshintshwa: 1.3-3.0;i-etherification agent, i-ethylene oxide;ukunyibilikisa isinyibilikisi, amanzi;
I-Hydroxyethyl methylcellulose (HEMC), isidanga esisebenzayo sokutshintshwa: 1.5-2.0;i-etherification agent, i-ethylene oxide, i-methyl chloride;ukunyibilikisa isinyibilikisi, amanzi;
I-Hydroxypropyl cellulose (HPC), iqondo elisebenzayo lokutshintshwa: 2.5-3.5;i-etherification agent, ipropylene oxide;ukunyibilikisa isinyibilikisi, amanzi;
I-Hydroxypropyl methylcellulose (HPMC), isidanga esisebenzayo sokutshintshwa: 1.5-2.0;i-etherification agent, ipropylene oxide, i-methyl chloride;ukunyibilikisa isinyibilikisi, amanzi;
I-Ethyl cellulose (EC), iqondo elisebenzayo lokutshintshwa: 2.3-2.6;i-etherification agent, i-monochloroethane;ukunyibilikisa isinyibilikisi, isinyibilikisi se-organic;
I-Ethyl hydroxyethyl cellulose (EHEC), isidanga esisebenzayo sokutshintshwa: 2.4-2.8;i-etherification agent, i-monochloroethane, i-ethylene oxide;ukunyibilikisa isinyibilikisi, isinyibilikisi se-organic;
1.3 Iimpawu zeselulosi
1.3.1 I-Methyl cellulose ether (MC)
①Methylcellulose iyanyibilika emanzini abandayo, kwaye kuya kuba nzima ukuyinyibilika emanzini ashushu.Isisombululo saso samanzi sizinzile kakhulu kuluhlu lwe-PH = 3-12.Inokuhambelana kakuhle nestatshi, i-guar gum, njl. kunye nee-surfactants ezininzi.Xa iqondo lokushisa lifikelela kwiqondo lokushisa, i-gelation iyenzeka.
② Ukugcinwa kwamanzi kwe-methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, i-particle fineness kunye nesantya sokuchithwa.Ngokuqhelekileyo, ukuba isixa songezelelo sikhulu, i-fineness incinci, kwaye i-viscosity inkulu, ukugcinwa kwamanzi kuphezulu.Phakathi kwabo, inani lokongezwa linempembelelo enkulu ekugcinweni kwamanzi, kwaye i-viscosity ephantsi kakhulu ayihambelani ngokuthe ngqo kwinqanaba lokugcinwa kwamanzi.Izinga lokuchithwa ikakhulu lixhomekeke kwiqondo lokuguqulwa komphezulu wamasuntswana e-cellulose kunye ne-particle fineness.Phakathi kwe-cellulose ethers, i-methyl cellulose inezinga eliphezulu lokugcinwa kwamanzi.
③Ukutshintsha kweqondo lobushushu kuyakuchaphazela ngokumandla izinga logcino lwamanzi lwe-methyl cellulose.Ngokuqhelekileyo, okukhona ubushushu buphezulu, kokukhona ukugcinwa kwamanzi kubi.Ukuba ubushushu bomdaka budlula i-40 ° C, ukugcinwa kwamanzi kwe-methyl cellulose kuya kuba nzima kakhulu, okuya kuchaphazela kakhulu ukwakhiwa kodaka.
④ I-Methyl cellulose inempembelelo ebalulekileyo kulwakhiwo kunye nokunamathela kodaka.“Ukuncamathisela” apha kubhekisa kumandla okuncamathelisa okuvakala phakathi kwesixhobo sokufaka isicelo somsebenzi kunye nenxalenye yodonga, oko kukuthi, ukuxhathisa kokucheba kodaka.I-adhesiveness iphezulu, ukuxhathisa ukucheba kodaka kukhulu, kwaye abasebenzi bafuna amandla amaninzi ngexesha lokusetyenziswa, kwaye ukusebenza kokwakhiwa kodaka kuba nzima.I-Methyl cellulose adhesion ikwinqanaba eliphakathi kwiimveliso ze-cellulose ether.
1.3.2 Hydroxypropyl Methyl Cellulose Ether (HPMC)
IHydroxypropyl methylcellulose yimveliso yefiber ephuma kunye nokusetyenziswa kwayo kusanda ngokukhawuleza kwiminyaka yakutshanje.
I-ether engeyiyo i-ionic cellulose exutywe ne-ether eyenziwe kwi-cotton ecocekileyo emva kwe-alkalization, isebenzisa i-propylene oxide kunye ne-methyl chloride njengee-etherification agents, kunye noluhlu lweempendulo.Umgangatho wokutshintshwa ngokubanzi ngu-1.5-2.0.Iimpawu zayo zihluke ngenxa yemilinganiselo eyahlukeneyo yomxholo we-methoxyl kunye nomxholo we-hydroxypropyl.Umxholo ophezulu we-methoxyl kunye nomxholo ophantsi we-hydroxypropyl, ukusebenza kusondele kwi-methyl cellulose;umxholo we-methoxyl ophantsi kunye nomxholo ophezulu we-hydroxypropyl, ukusebenza kusondele kwi-cellulose ye-hydroxypropyl.
①I-Hydroxypropyl methylcellulose inyibilika ngokulula emanzini abandayo, kwaye kuya kuba nzima ukuyinyibilika emanzini ashushu.Kodwa ubushushu bayo be-gelation emanzini ashushu buphezulu kakhulu kune-methyl cellulose.Ukunyibilika kumanzi abandayo kuphuculwe kakhulu xa kuthelekiswa ne-methyl cellulose.
② I-viscosity ye-hydroxypropyl methylcellulose ihambelana nesisindo sayo se-molecular, kwaye ukuphakama kwe-molecular weight, kuphezulu kwe-viscosity.Ubushushu buchaphazela i-viscosity yayo, njengoko izinga lokushisa linyuka, i-viscosity iyancipha.Kodwa i-viscosity yayo ayichatshazelwa kangako bubushushu kune-methyl cellulose.Isisombululo sayo sizinzile xa sigcinwe kwiqondo lokushisa.
③ Ukugcinwa kwamanzi e-hydroxypropyl methylcellulose kuxhomekeke kwisixa-mali sayo esongeziweyo, i-viscosity, njl.
④I-Hydroxypropyl methylcellulose izinzile kwi-asidi kunye ne-alkali, kwaye isisombululo sayo samanzi sizinzile kakhulu kuluhlu lwe-PH = 2-12.I-Caustic soda kunye namanzi ekalika anempembelelo encinci ekusebenzeni kwayo, kodwa i-alkali inokukhawulezisa ukuchithwa kwayo kwaye yandise i-viscosity yayo.I-Hydroxypropyl methylcellulose izinzile kwiityuwa eziqhelekileyo, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity ye-hydroxypropyl methylcellulose isisombululo ivame ukunyuka.
⑤I-Hydroxypropyl methylcellulose inokuxutywa kunye neepolymers ezinyibilikayo zamanzi ukwenza isisombululo esifanayo kunye neselubala kunye ne-viscosity ephezulu.Okufana ne-polyvinyl alcohol, i-starch ether, i-gum yemifuno, njl.
⑥ I-Hydroxypropyl methylcellulose inokumelana ne-enzyme engcono kune-methylcellulose, kwaye isisombululo sayo sincinci ukuba sithotywe yi-enzymes kune-methylcellulose.
⑦ Ukunamathela kwe-hydroxypropyl methylcellulose kulwakhiwo lodaka kuphezulu kune-methylcellulose.
1.3.3 I-Hydroxyethyl cellulose ether (HEC)
Yenziwe kwikotoni esulungekileyo ephathwe nge-alkali, kwaye iphendule nge-ethylene oxide njenge-etherification agent phambi kwe-acetone.Umgangatho wokutshintshwa ngokubanzi ngu-1.5-2.0.Ine-hydrophilicity eyomeleleyo kwaye kulula ukufunxa ukufuma.
①Iselulosi yeHydroxyethyl iyanyibilika emanzini abandayo, kodwa kunzima ukuyinyibilikisa emanzini ashushu.Isisombululo saso sizinzile kwiqondo lokushisa eliphezulu ngaphandle kwe-gelling.Ingasetyenziselwa ixesha elide phantsi kobushushu obuphezulu kwidaka, kodwa ukugcinwa kwamanzi kwayo kuphantsi kune-methyl cellulose.
②I-Hydroxyethyl cellulose izinzile kwi-asidi jikelele kunye ne-alkali.I-alkali inokukhawulezisa ukuchithwa kwayo kwaye inyuse kancinci i-viscosity yayo.I-dispersibility yayo emanzini imbi kancinane kune-methyl cellulose kunye ne-hydroxypropyl methyl cellulose.
③Iselulosi yeHydroxyethyl inomsebenzi olungileyo wokuchasana nodaka, kodwa inexesha elide lokubuyiswa kwesamente.
④Ukusebenza kwe-hydroxyethyl cellulose eveliswa ngamanye amashishini asekhaya ngokucacileyo isezantsi kune-methyl cellulose ngenxa yomthamo wayo ophezulu wamanzi kunye nomxholo ophezulu wothuthu.
1.3.4 I-Carboxymethyl cellulose ether (i-CMC) yenziwe ngemicu yendalo (ikotoni, i-hemp, njl.) emva kokunyangwa kwe-alkali, isebenzisa i-sodium monochloroacetate njenge-etherification agent, kwaye ihamba ngeendlela zonyango zokuphendula ukwenza i-ionic cellulose ether.Iqondo lokutshintshwa ngokubanzi li-0.4-1.4, kwaye ukusebenza kwayo kuchaphazeleka kakhulu yinqanaba lokutshintshwa.
①I-Carboxymethyl cellulose ine-hygroscopic ephezulu, kwaye iya kuba nesixa esikhulu samanzi xa igcinwe phantsi kweemeko eziqhelekileyo.
②I-Hydroxymethyl cellulose isisombululo samanzi asiyi kuvelisa i-gel, kwaye i-viscosity iya kuncipha ngokunyuka kweqondo lokushisa.Xa ubushushu bungaphezu kwama-50 ℃, i-viscosity ayinakuguqulwa.
③ Uzinzo lwayo luchatshazelwa kakhulu yi-pH.Ngokuqhelekileyo, inokusetyenziswa kwi-gypsum-based mortar, kodwa kungekhona kwi-samente-based mortar.Xa i-alkaline iphezulu, ilahlekelwa yi-viscosity.
④ Ukugcinwa kwawo kwamanzi kuphantsi kakhulu kune-methyl cellulose.Unempembelelo ephazamisayo kwi-gypsum-based mortar kwaye inciphisa amandla ayo.Nangona kunjalo, ixabiso le-carboxymethyl cellulose liphantsi kakhulu kunelo le-methyl cellulose.
2. I-ether yesitatshi elungisiweyo
Ii-ethers zesitatshi ezisetyenziswa ngokubanzi kudaka zilungiswa ukusuka kwiipolima zendalo zezinye iipolysaccharides.Njengeetapile, umbona, icassava, iimbotyi zeguar, njl.njl. zitshintshwa zibe yi-ethers yesitatshi elungisiweyo.Isitashi se-ethers esiqhele ukusetyenziswa kudaka yi-hydroxypropyl starch ether, i-hydroxymethyl starch ether, njl.
Ngokuqhelekileyo, ii-ethers zesitatshi eziguqulwe kwiitapile, umbona, kunye necassava zinokugcina amanzi okusezantsi kakhulu kuneethers ze-cellulose.Ngenxa yomgangatho wayo ohlukeneyo wokuguqulwa, ibonisa ukuzinza okwahlukileyo kwi-asidi kunye ne-alkali.Ezinye iimveliso zifanelekile ukuba zisetyenziswe kwi-gypsum-based mortars, ngelixa ezinye azikwazi ukusetyenziswa kwi-samente-based mortars.Ukusetyenziswa kwe-starch ether kwi-mortar kusetyenziswa kakhulu njenge-thickener yokuphucula ipropathi echasene ne-sagging yodaka, ukunciphisa ukunamathela kodaka olumanzi, kunye nokwandisa ixesha lokuvula.
Isitatshi ethers zihlala zisetyenziswa kunye neselulosi, okukhokelela kwiipropati ezihambelanayo kunye noncedo lweemveliso ezimbini.Njengoko iimveliso ze-ether zestatshi zitshiphu kakhulu kune-ether ye-cellulose, ukusetyenziswa kwe-ether yesitatshi kudaka kuya kuzisa ukuncipha okubonakalayo kwindleko yokwenziwa kodaka.
3. Igum gum ether
I-Guar gum ether luhlobo lwe-polysaccharide etherified eneempawu ezikhethekileyo, eziguqulwa ukusuka kwiimbotyi ze-guar zendalo.Ikakhulu ngokusabela kwe-etherification phakathi kwe-guar gum kunye namaqela asebenzayo e-acrylic, isakhiwo esine-2-hydroxypropyl amaqela asebenzayo akhiwa, okuyisakhiwo se-polygalactomannose.
① Xa kuthelekiswa ne-cellulose ether, iguar gum ether kulula ukuyinyibilika emanzini.I-PH ngokusisiseko ayinayo impembelelo ekusebenzeni kwe-guar gum ether.
②Ngaphantsi kweemeko ze-viscosity ephantsi kunye ne-dosage ephantsi, i-guar gum ingathatha indawo ye-cellulose ether ngenani elilinganayo, kwaye inokugcinwa kwamanzi okufanayo.Kodwa ukuhambelana, i-anti-sag, i-thixotropy kunye nokunye ngokucacileyo kuphuculwe.
③Ngaphantsi kweemeko ze-viscosity ephezulu kunye nedosi enkulu, i-guar gum ayinakuthatha indawo ye-cellulose ether, kunye nokusetyenziswa okuxubileyo kokubini kuya kuvelisa ukusebenza okungcono.
④Ukusetyenziswa kwe-guar gum kwi-gypsum-based mortar kunokunciphisa kakhulu ukunamathela ngexesha lokwakha kwaye wenze ulwakhiwo lube lula.Ayinayo impembelelo embi kwixesha lokumisela kunye namandla omdaka we-gypsum.
⑤ Xa igum guar igalelwa kwisamente esekwe kwimasonry kunye nodaka lokutyatyekwa, inokutshintsha i-ether yeselulosi ngenani elilinganayo, kwaye inike udaka ngokuxhathisa okuhexayo, ithixotropy kunye nokuguda kolwakhiwo.
⑥Kudaka olunokubonakala okuphezulu kunye nesiqulatho esiphezulu searhente yokugcina amanzi, iguar gum kunye ne-cellulose ether ziyakusebenza kunye ukuzuza iziphumo ezigqwesileyo.
⑦ I-Guar gum ingasetyenziselwa kwiimveliso ezifana nokunamathiswa kweethayile, ii-agent zokuzilinganisa emhlabeni, i-putty engangeni manzi, kunye ne-polymer mortar yokugquma eludongeni.
4. I-thickener yokugcina amanzi eminerali elungisiweyo
I-thickener yokugcina amanzi eyenziwe ngeeminerali zendalo ngokuguqulwa kunye nokudibanisa isetyenziswe e-China.Iiminerali eziphambili ezisetyenziselwa ukulungisa i-thickeners yokugcina amanzi zezi: i-sepiolite, i-bentonite, i-montmorillonite, i-kaolin, njl.Olu hlobo lwe-thickener yokugcina amanzi efakwe kwidaka inezi mpawu zilandelayo.
① Inokuphucula kakhulu ukusebenza kodaka oluqhelekileyo, kunye nokusombulula iingxaki zokungasebenzi kakuhle kodaka lwesamente, amandla aphantsi odaka oluxutyiweyo, kunye nokunganyangeki kwamanzi.
② Iimveliso zodaka ezinamanqanaba ahlukeneyo omelela kwimizi-mveliso jikelele kunye nezakhiwo zasekuhlaleni zinokuqulunqwa.
③Ixabiso lemathiriyeli liphantsi.
④ Ukugcinwa kwamanzi kuphantsi kune-organic water retention agents, kwaye ixabiso elomileyo le-shrinkage yodaka olulungisiweyo lukhulu kakhulu, kwaye ukubambisana kuyancipha.
Ixesha lokuposa: Mar-03-2023