I-cellulose ethers, ngakumbi i-hydroxypropylmethylcellulose (HPMC) kunye ne-methylhydroxyethylcellulose (MHEC), isetyenziswe ngokubanzi njengezongezo ze-cementitious kwizicelo zokwakha. Eyaziwayo ngeempawu zabo zokugcina amanzi, ezi zixhobo zinokuphucula ukusebenza, i-rheology kunye namandla ebhondi yezinto ze-cementitious. Nangona kunjalo, impembelelo yabo kwi-cement hydration ayisoloko icacile.
I-Cement hydration ibhekisela kwindlela yokusabela kweekhemikhali phakathi kwamanzi kunye nezixhobo ze-cementitious ukuvelisa iimveliso ze-hydration ezifana ne-calcium silicate hydrate (CSH) kunye ne-calcium hydroxide (Ca (OH) 2). Le nkqubo ibalulekile kuphuhliso lwamandla oomatshini bekhonkrithi kunye nokuqina.
Ukongezwa kwe-cellulose ethers kwizinto ze-cementitious zinokuba nemiphumo emihle kunye nembi kwinkqubo yokufakwa kwamanzi. Kwelinye icala, ukugcinwa kwamanzi kwi-ether ye-cellulose kunokukhuthaza isamente ukuba iqhubeke ifumana amanzi okusabela, ngokwenjenjalo yandisa isantya kunye neqondo lokugalela amanzi. Oku kunciphisa ixesha lokumisela, ukukhawuleza ukuphuhliswa kwamandla kunye nokuphucula iimpawu ezipheleleyo zekhonkrithi.
I-ether ye-cellulose inokusebenza njenge-colloid yokukhusela ukukhusela ukuhlanganiswa kunye nokuhlaliswa kweengqungquthela zesamente. Oku kubangela i-microstructure efanayo kunye nezinzile, eqhubela phambili ukunyusa umatshini kunye neempawu ezizinzileyo zekhonkrithi.
Kwelinye icala, ukusetyenziswa ngokugqithisileyo kwe-cellulose ethers kunokuchaphazela kakubi ukuhanjiswa kwesamente. Ngenxa yokuba i-cellulose ether iyingxenye ye-hydrophobic, ivimbela ukungena kwamanzi kwi-gelling material, okubangelwa ukulibaziseka okanye ukungagqibeki kwe-hydration. Oku kubangela ukunciphisa amandla kunye nokuqina kwekhonkrithi.
Ukuba i-concentration ye-cellulose ether iphezulu kakhulu, iya kuthatha indawo kwi-sement slurry ekufuneka izaliswe ngamaqhekeza e-samente. Ngenxa yoko, umxholo opheleleyo we-slurry uya kuncipha, okukhokelela ekunciphiseni iimpawu zomatshini. I-ethers ye-cellulose eyongezelelweyo inokuthi isebenze njengomqobo, ukuthintela ukusebenzisana phakathi kweengqungquthela zesamente kunye namanzi, ukuqhubela phambili ukucotha inkqubo ye-hydration.
Kubalulekile ukumisela ubungakanani be-ether yeselulosi ekufuneka isetyenziswe ukuphucula iipropathi zemathiriyeli yejeli ngelixa unqanda nayiphi na impembelelo engalunganga kwi-hydration. Isixa sixhomekeke kwizinto ezininzi, ezifana nohlobo lwe-cellulose ether, ukubunjwa kwesamente, umlinganiselo wamanzi-samente kunye neemeko zokuphilisa.
I-cellulose ethers, ngakumbi i-HPMC kunye ne-MHEC, ingaba nefuthe elihle kwi-cement hydration, kuxhomekeke ekugxininiseni kwabo kunye nokubunjwa okuthe ngqo kwezinto ze-cementitious. Isixa se-cellulose ether esetyenzisiweyo kufuneka siqwalaselwe ngokucophelela ukufezekisa iipropati ezifunwayo ngaphandle kokunciphisa iimpawu zekhonkrithi. Ngokusetyenziswa ngokufanelekileyo kunye nokulungiswa, i-cellulose ethers inokufaka isandla ekuphuhliseni izinto zokwakha ezihlala ixesha elide, ezihlala ixesha elide kunye nezizinzileyo.
Ixesha lokuposa: Aug-23-2023