_^^ KHOA HOC VA CONG NGHE MO 1I€T LAP M O HINH TINH TORN MU^C D O THUV HOn XI MANG VA CAC CHAT PHU GIA KHOANG HOAT TJNH TS N G U Y £ N TRQNG D O N G Trwdfig D%i hgc Mo-Dja chat y hlnh thdnh va phdt tridn cde tinh ch^t co hpe eQa bd tdng td bit dau tr$n den I ktii dat cu'dng dp sd dgng phg thuOc rit Idn vdo qud trinh thuy h6a cde chdt kit dinh lh phin clinker xi mdng cQng nhu' edc : phg gia khodng hoat tinh (tro bay, mupi silic, xi JO ) dup'c thdm vao Tuy nhiSn, ddnh gid mdc huy hda eua edc chit ket dinh ndy qud I ninh ket eua bS tong Id cdng vi0c het sdc khd edc CO" chl phan dng hda ly phdc tap d : dp phdn td cua cde thdnh phan tham gia ig tido edo ndy, tde gia gidi thi^u mpt phu'ong p s6 thdng qua vipc phdn tieh ca chl phan dng fo nhi^t lu'p'ng tda qud trinh thuy hda phdp tinh todn tie dd thuy hda cua cdc chat Jinh thdnh phin h i xi mdng San phdm cOa qud trinh thuy hda clinker xi mdng ngodi cde ehdt kit dinh tip C-S-H cdn cd CH (canxi hydroxit), ddy la hp'p chdt khdng I n djnh dd pH be tdng nhd hon 12,5 vd cd t h i bj hda tan nudc Idm giam dO on dinh va dp ben cua be tdng D l khdc phue nhu-pc diem ndy vd hudng tdi vide cai thidn cudng dp bd tdng, vi^c trOn thdm cde phy gia khodng hoat tinh dd dupe dp dgng rpng rdi Cdc phg gia khodng tidu bilu nhu tro bay, mupi silic, xi Id cao, hay cdn gpi Id cdc chit pozzolan ndi ehung (tinh chit pozzolan Id tinh chit cua cde hp'p chdt chda exit silie ed t h i phan dng vdi canxi hydroxit) se phan dng vdi CH d l tao cdc chit kit dinh I n djnh, qua eai thipn cudng dO vd dd bin cua bd tdng Cdc phan dng ndy dup'c Thuy hoa xi mang va cac phan irng thuy gpi Chung Id cde phan dng pozzolanic vdi ty Id phan dng dupe nghidn cdu vd trinh bay rat >a pozzolanic ddi vdi phg gia khoang Hi^n nay, tren th^ gidi cQng nhu- tai Vipt Nam, xi nhieu bdo edo [6], [7], [8], [9] Trong Bang 1, tde gia gidi thidu dudi dang tong 5ng du'pc sd dgng ph6 biln xdy dyng chu u Id xi mdng Portland (pode lang) cd thdnh phan hpp cdc phuang trinh phan dng thuy hda xi mang inh Id clinker Portland, tdc nhdn tgo nen tinh ket vd phan dng pozzolanic Luu y rdng cdc lh cua xi mdng Xdt ve hdm lu'p'ng cdc hp'p ehdt phuong trinh phan dng cua C3A vd C4AF cd sy (nh, thdng qua phu'ong phap phdn tich eua xuat hidn cua hpp chat CSH^ hay cdn gpi Id thaeh igue [1], it nhit 2/3 khii lu'p'ng cua clinker phai cao Day Id hp'p chat thudng dupc them vdo •