Umhla wokuThumela:1,Epreli,2024
Ngokuqhelekileyo kukholelwa ukuba iqondo lokushisa liphezulu, ngakumbi amaqhekeza e-samente aya kubhengeza i-agent yokunciphisa amanzi ye-polycarboxylate. Kwangaxeshanye, okukhona iqondo lobushushu liphezulu, kokukhona kucaca ngakumbi ukuba iimveliso zesamente ze-hydration ziya kusebenzisa i-agent yokunciphisa amanzi ye-polycarboxylate. Ngaphantsi kwempembelelo edibeneyo yemiphumo emibini, njengoko izinga lokushisa linyuka, umbane wekhonkrithi uba mbi. Esi sigqibo sinokuyichaza kakuhle into yokuba i-fluidity yekhonkrithi iyanda xa iqondo lokushisa lihla ngokukhawuleza, kwaye ukulahleka kwe-slump yekhonkrithi kwanda xa ubushushu buphakama. Nangona kunjalo, ngexesha lokwakhiwa, kwafunyaniswa ukuba umbane wekhonkrithi uhlwempuzekileyo kumaqondo aphantsi, kwaye xa ukushisa kwamanzi okuxutywayo kwanda, i-fluidity yekhonkrithi emva kokunyuka komatshini. Oku akunakuchazwa sesi sigqibo singasentla. Kule njongo, iimvavanyo zenziwa ukuhlalutya, ukufumana izizathu zokuchasana, kunye nokubonelela ngeqondo lokushisa elifanelekileyo lekhonkrithi.
Ukuze ufunde umphumo wokuxuba ubushushu bamanzi kwisiphumo sokusasazeka kwe-polycarboxylate yokunciphisa amanzi. Amanzi akwi-0°C, 10°C, 20°C, 30°C, kunye nama-40°C alungiswa ngokulandelelanayo kuvavanyo lokuhambelana kwesamente-superplasticizer.
Uhlalutyo lubonisa ukuba xa ixesha lokuphuma kumatshini lifutshane, ukwanda kwe-samente slurry kuqala kwanda kwaye kuyancipha njengoko ubushushu bukhula. Isizathu sale nto kukuba ukushisa kuchaphazela zombini isantya se-sement hydration kunye nesantya se-adsorption ye-superplasticizer. Xa iqondo lobushushu linyuka, ukukhawuleza kwesantya sokubhengezwa kweemolekyuli ze-superplasticizer, kokukhona kuya kuba ngcono ukusasazeka kwangaphambili. Ngelo xesha, izinga le-hydration ye-samente likhawuleza, kwaye ukusetyenziswa kwe-agent yokunciphisa amanzi ngeemveliso ze-hydration kwandisa, okunciphisa umbane. Ukwandiswa kokuqala kwe-cement paste kuchaphazeleka yimpembelelo edibeneyo yale miba mibini.
Xa ukushisa kwamanzi okuxutywayo ku-≤10 ° C, izinga le-adsorption ye-superplasticizer kunye ne-cement hydration rate zombini zincinci. Phakathi kwabo, i-adsorption ye-agent yokunciphisa amanzi kwiinqununu ze-samente yinto yokulawula. Ekubeni i-adsorption ye-agent yokunciphisa amanzi kwiincinci ze-samente iyancipha xa iqondo lokushisa liphantsi, izinga lokuqala lokunciphisa amanzi liphantsi, elibonakaliswa kwi-fluidity yokuqala ephantsi ye-cement slurry.
Xa ukushisa kwamanzi okuxutywa phakathi kwe-20 kunye ne-30 ° C, izinga le-adsorption ye-agent yokunciphisa amanzi kunye nesantya se-hydration yokwanda kwe-samente ngexesha elifanayo, kunye nesantya sokubhengezwa kwe-agent ye-agent yokunciphisa amanzi kwandisa ngakumbi. ngokucacileyo, nto leyo ebonakaliswa ukwanda ulwelo lokuqala ludaka lwesamente. Xa ukushisa kwamanzi okuxutywa ku-≥40 ° C, isantya se-sement hydration sanda kakhulu kwaye ngokuthe ngcembe siba yinto yokulawula. Ngenxa yoko, i-net adsorption rate ye-agent agent yokunciphisa amanzi (izinga le-adsorption minus rate rate) liyancipha, kwaye i-cement slurry ibonisa ukuncitshiswa kwamanzi okwaneleyo. Ngoko ke, kukholelwa ukuba umphumo wokuqala wokusabalalisa we-arhente yokunciphisa amanzi ungcono xa amanzi okuxuba phakathi kwe-20 kunye ne-30 ° C kunye nobushushu be-samente buphakathi kwe-18 kunye ne-22 ° C.
Xa ixesha lokuphuma komatshini lide, ukwandiswa kwe-samente slurry kuhambelana nesigqibo esamkelwe ngokubanzi. Xa ixesha lanele, i-agent ye-polycarboxylate yokunciphisa amanzi ingabhengezwa kwiinqununu ze-samente kwiqondo lokushisa ngalinye lize lihluthe. Nangona kunjalo, kwiqondo lokushisa eliphantsi, i-agent encinci yokunciphisa amanzi isetyenziselwa i-cement hydration. Ngoko ke, njengoko ixesha lihamba, ukwandiswa kwe-sement slurry kuya kwanda ngobushushu. Yandisa kwaye unciphise.
Olu vavanyo aluqwalaseli kuphela umphumo weqondo lokushisa, kodwa lunika ingqalelo kwisiphumo sexesha kwisiphumo sokusasazeka kwe-agent ye-polycarboxylate yokunciphisa amanzi, okwenza isiphelo sicace ngakumbi kwaye sisondele kwinyani yobunjineli. Izigqibo ezifikelelweyo zezi zilandelayo:
(1) Kwiqondo lokushisa eliphantsi, umphumo wokusasazwa kwe-arhente yokunciphisa amanzi ye-polycarboxylate inexesha elicacileyo. Njengoko ixesha lokuxuba landa, i-fluidity ye-sement slurry iyanda. Njengoko ukushisa kwamanzi okuxutywa kwanda, ukwandiswa kwe-sement slurry kuqala kwanda kwaye emva koko kuyancipha. Kunokubakho umahluko omkhulu phakathi kwemeko yekhonkrithi njengoko iphuma kumatshini kunye nemeko yekhonkrithi njengoko igalelwa kwisiza.
(2) Ngexesha lokwakhiwa kobushushu obuphantsi, ukufudumeza amanzi okuxuba kunokunceda ukuphucula i-fluidity lag yekhonkrithi. Ngethuba lokwakha, ingqalelo kufuneka ihlawulwe ekulawuleni ukushisa kwamanzi. Ubushushu boludaka lwesamente luphakathi kwe-18 kunye ne-22 ° C, kwaye ulwelo lungcono xa luphuma kumatshini. Thintela isenzeko sokuncitshiswa kwe-fluidity yekhonkrithi ebangelwa bubushushu bamanzi obugqithisileyo.
(3) Xa ixesha lokuphuma komatshini lilide, ukwandiswa kodaka lwesamente kuncipha njengoko ubushushu bunyuka.
Ixesha lokuposa: Apr-01-2024
