Hi ngh khoa hc k nim 50 nm ngy thnh lp Vin KHCN Xy dng

1 Khoa Vt liu Xy dng, Trng i hc Xy dng, kientt@nuce.edu.vn, +84 977966357 2 Trng Cao ng Xy dng s 1 3 B Xy dng

B TNG GEOPOLYMER- NHNG THNH TU, TNH CHT V NG DNG

NCS. ThS. Tng Tn Kin*1, ThS. Phm Th Vinh Lanh2, TS. L Trung Thnh3

TM TT:

Gepolymer l sn phm ca qu trnh phn ng gia vt liu c ngun gc silic v nhm vi dung dch kim. Vt liu ny c th thay th xi mng trong b tng. Hin nay Geopolymer v ang c nghin cu rng ri v cho thy kh nng l vt liu xanh hn thay th b tng xi mng trong mt s ng dng do b tng geopolymer va c cc tnh cht k thut tt, ng thi gim kh nng gy hiu ng nh knh khi thay th xi mng pooclng. Nghin cu ny trnh by tm tt lch s pht trin, cc tnh cht ca b tng geopolymer cng nh cc ng dng cng ngh b tng geopolymer trong nhng nm gn y trn th gii v Vit nam. Trn c s , bi bo cn xut nhng nh hng nghin cu v kh nng ng dng cng ngh b tng geopolymer trong xy dng bn vng Vit nam.

T KHA: Geopolymer, b tng geopolymer, b tng khng xi mng, xy dng bn vng

1. NHNG THNH TU NGHIN CU V B TNG GEOPOLYMER

B tng Geopolymer l loi b tng khng s dng cht kt dnh xi mng pooc lng thng thng m l sn phm ca phn ng gia dung dch kim v cc loi vt liu c cha hm lng ln hp cht silic v nhm. Cht kt dnh ny cng c th gi l cht kt dnh kim hot ha. Bng 1 nu ln mt s mc thi gian quan trng trong lnh vc pht trin cht kt dnh kim hot ha.

Cht kt dnh kim hot ha ch yu do Purdon nghin cu [2] vo nhng nm 1940. Tc gi s dng x l cao c kch hot bng dung dch hydroxit natri. Theo ng qu trnh pht trin cu trc gm 2 bc: trc tin xy ra qu trnh gii phng cc hp cht nhm- silic v hydroxit canxi. Sau xy ra s hydrat ha nhm v silic ng thi ti to dung dch kim. Tuy nhin, ngi ta ni rng Gluskhovsky [12] l ngi u tin kho st loi cht kt dnh c s dng trong xy dng cng trnh thi k La m v Ai cp c i. ng cho rng cc cng trnh ny c to nn bi hp cht hydro canxi aluminat ging nh mt loi xi mng poc lng v cng c pha thy tinh analcite, mt loi t nhin. iu ny c th gii thch tnh bn vng ca nhng loi cht kt dnh ny. Trn c s kho st ny Gluskhovsky pht trin mt loi cht kt dnh mi v gi l xi mng t (Soil-cement). T t do chng ging mt loi t cn t xi mng do n c kh nng gn kt. Xi mng t c thnh phn t hn hp t cha mui Aluminosilicat v ph thi cng nghip giu kim.

Phn ln cc nghin cu kho st v cht kt dnh kim hot ha u c ngun gc t s hot ha x l cao nn gi l Xi mng x kim Alkali-slag cement hay Xi mng x kim hot ha Alkali-activated slag. X l cao l sn phm ca cng nghip sn xut thp, l loi vt liu kt dnh cht lng thp, khi s dng cht kim kch hot c th t cng nn cao. Shi v Day [16] cho rng khi s dng cht kim kch hot l Na2O.nSiO3 th cng nn c th t 160 Mpa sau 90 ngy bo dng nhit phng.

Bng 1. Mc thi gian chnh v s pht trin ca cht kt dnh hot ha kim, [15]

Tc gi Nm S kin ni bt Feret 1939 Dng s dng x cho xi mng Purdon 1940 S kt hp x v kim Glukhovsky 1959 L thuyt c bn v s pht trin ca cht kt dnh kim (alkaline cements) Glukhovsky 1965 Ln u tin gi Xi mng kim alkaline cements Davidovits 1979 Khi nim Geopolymer

Forss 1983 Xi mng F (F-cement) (Ph gia siu do x kim- slag-alkali-superplasticizer)

Langton and Roy c tnh vt liu xy dng c i Langton and Sawyer 1984 Bng sng ch v xi mng Pyrament Majundar et al. 1989 C12A7 X hot ha Talling and Brandstetr 1989 X kim hot ha (Alkali-activated slag) Wu et al. 1990 Cht hot ha ca xi mng x Roy et al. 1991 Xi mng rn nhanh kim hot ha (Rapid setting alkali-activated cements) Roy and Malek 1993 Xi mng x Krivenko 1994 Xi mng kim tnh (Alkaline cements) Wang and Scrivener 1995 Vi cu trc ca X kim hot ha Shi 1996 Cng , cu trc l rng v tnh thm nc ca X kim hot ha Fernndez-Jimnez and Puertas

1997 Nghin cu ng hc ca cht kt dnh x kim hot ha

Katz 1998 Vi cu trc ca Tro bay kim hot ha (Alkali-activated y ash) Palomo 1999 Tro bay kim hot ha- Cht kt dnh cho tng lai

Gong and Yan 2000 Cht kt dnh bn -X kim hot ha (Alkali-activated red mudslag cement)

Puertas 2000 Cht kt dnh Tro bay/X kim hot ha (Alkali-activated y ash/slag cement)

Bakharev 2001-2001

B tng x kim hot ha (Alkali-activated slag concrete)

Grutzeck 2004 S hnh thnh khong Zeolite Sun 2006 Cng ngh Sialite Duxson 2007 Cng ngh Geopolymer

Provis and Deventer 2009 Geopolymers: Cu trc, qu trnh sn xut, tnh cht v ng dng cng nghip

C nhiu nghin cu v cht kim hot ha sau kt qu nghin cu ca tc gi ngi Php Davidovits [12]. ng nghin cu pht trin v c nhn bng sng ch v cht kt dnh Mta cao lanh s dng kim kch hot, sau ny gi l Geopolymer vo nm 1978. Theo Davidovits, geopolymer l loi polymer v c s chuyn bin th hnh, polyme ha v ng rn nhit

thp. Nhng chng cng l hp cht v c, cng v n nh nhit cao ng thi khng b chy. C chn loi geopolymer khc nhau, nhng loi c kh nng ng dng nhiu nht trong xy dng l loi vt liu alumo silicat. Nhng loi geopolymer ny da vo qu trnh nhit hot ha cc vt liu t nhin (nh M ta caolanh) hoc sn phm ca cng nghip (nh tro bay, x) nhm cung cp ngun vt liu silic (Si) v nhm (Al) s c ha tan vi dung dch kim kch hot ri sau thc hin qu trnh trng hp to thnh chui phn t to cht kt dnh [7].

Vit Nam, c mt s nghin cu bc u v b tng geopolyme nh: Cng ngh sn xut gch khng nung ca cng ty Hu Quang (2009), Nghin cu ch to gch khng nung bng cng ngh geopolymer s dng tro bay v ph thi bn xy dng nh vng cao nguyn Vit Nam ca nhm nghin cu trng i hc Bch khoa TP.HCM (2010), va v b tng s dng cht kt dnh polyme v c ca nhm nghin cu trng i hc Giao thng vn ti H Ni (2011), B tng chu la v gch khng nung s dng cht kt dnh geopolyme ca cc nhm ngin cu Vin Vt liu xy dng (2012).

2. QU TRNH HNH THNH CU TRC CA B TNG GEOPOLYMER

2.1. C ch phn ng ca cht kt dnh geopolymer

Trn c s rt nhiu nghin cu v cht kt dnh kim kch hot (alkali-activated cements), ngi ta chp nhn c 2 khi nim khc nhau l x l cao nghin mn kim kch hot (alkali activated GGBFS) v geopolymer. Cht kim kch hot ca GGBFS c kiu (Si+Ca) v Geopolymer c kiu cht kt dnh (Si+Al) vi Mta cao lanh v tro bay l vt liu chnh [12].

C ch ng hc phn ng gii thch qu trnh ng kt v rn chc ca cht kt dnh kim hot ha vn cn l 1 b n, mc d ngi ta cho rng n s ph thuc vo vt liu ban u v cht kim kch hot. Theo Glukhovsky [8], c ch qu trnh kim kch hot bao gm cc phn ng phn hy nguyn liu thnh dng cu trc n nh thp v phn ng ni ti. Trc tin l qu trnh b gy cc lin kt cng ha tr Si-O-Si v Al-O-Si khi PH ca kim tng ln. V th nhng nhm nguyn t ny c chuyn sang h keo. Sau xy ra s tch t cc sn phm b ph hy vi phn ng ni ti gia chng to cu trc n nh thp, tip theo giai on th 3 l qu trnh hnh thnh cu trc ng c, hnh 1.

Granizo [12] nghin cu cht kt dnh m ta cao lanh hot ha kim v cho rng c 2 phn ng khc nhau khi cht kim kch hot ch l NaOH hoc thy tinh lng. trng hp th nht, sau khi ha tan mt thi gian, cc sn phm b ph hy bt u tch t. Trong trng hp th 2, ngay sau khi xy ra s ha tan s xy ra qu trnh a trng hp.

Hnh 1. S m phng s hot ha vt liu alumosilicat [5]

Palomo et al. [13] cng c cng quan im ny khi cho rng, c hai kiu hot tnh kim c th xy ra, kiu th nht xy ra khi cht kch hot ca x l cao (Si+Ca) l dung dch kim yu, sn phm ch yu s l CSH. Kiu th 2 i vi cht hot ha kim ca m ta cao lanh l dung dch kim t trung bnh n mnh. Sn phm cui cng c dng mch trng hp v c cng c hc cao. Vi trng hp u tng t nh qu trnh hnh thnh zeoloite. V vy, c th kt lun rng cht kch hot ca m ta cao lanh to nn nhiu mch khng c hnh dng nht nh gn ging nh zeolite. Cn vi cht cht hot ha kim ca tro bay xy ra s ta nhit trong qu trnh ha tan, phn tch cc lin kt cng ha tr Si-O v Al-O-Al. Nhn chung cc sn phm ty thuc vo s ph v cu trc ca tro bay trong khong thi gian u v cui cng l qu trnh ngng kt to cu trc chui mt cch c trt t to kh nng c cng c hc cao.

Davidovits [1] cho rng dung dch kim c th c s dng phn ng vi silic v nhm trong ngun vt liu khong hoc trong vt liu ph thi nh tro bay, tro tru ch to cht kt dnh. Bi v phn ng ha hc xy ra trong trng hp ny l qu trnh trng hp cho nn ng gi l Geopolymer [11]. Thng s chnh quyt nh n tnh cht v dng s dng ca mt loi geopolymer l t l Si/Al. Vi vt liu xy dng t l Si/Al khong xp x 2.

2.2. Cc sn phm thy ha

Cc sn phm phn ng ty thuc vo c cht kch hot v vt liu ban u. Vi vt liu c cha (Si+Ca) th sn phm ch yu l gel CSH. Cn vi vt liu c (Si+Al) th sn phm phn ng l zeolite ging nh polyme [12]. Sn phm thy ha ca GGBFS hot ha kim c khng ch bi thnh phn ca x, loi cht kch hot v PH ca mi trng [2].

Nhiu tc gi [2] nhn ra rng sn phm ca m ta cao lanh vi dung dch NaOH l gel N-A-S-H c tnh cht c hc tt. iu ny c khng nh qua kt qu FTIR v 27Al, 29Si MAS-NMR, c cu trc mng 3 chiu [Q4(Al)] gm SiO4 v AlO4 lin kt vi nhau bng cch chung nguyn t O. Cng thc chung ca sn phm phn ng l 2SiO2.Al2O3.2H2O. Khi cht kch hot l hn hp NaOH v nc thy tinh, vt liu c to ra c dng v nh hnh v c tnh kt dnh, nhng cu trc v thnh phn ca chng khc so vi sn phm c to khi s dng cht kch hot ch l NaOH. Bn cnh , cc gel N-A-S-H v nh hnh c thnh phn ha hc ging nh vt liu khong zeolite t nhin nhng khng c cu trc tinh th zeolite ln.

Theo k hiu ha hc ca geopolymer do Davidoits xut [4] th dng tn polysialates, mi sialate l mt k hiu vit tt ca oxit kp aluminosilicat. Mng li sialate bao gm cc anion t din [SiO4]4- v [AlO4]5- chung nhau nguyn t oxy v chng cn cc ion dng nh (Na+, K+, Li+, Ba2+, NH4+, H3O+) cn bng in tch ca Al3+ trong khi t din. Polysialate c th vit tt theo cng thc: Mn{-SiO2)z-AlO3}n.wH2O, trong n l mc trng hp, z l 1, 2 hoc 3 v M l ion dng kim nh Kali, Natri. Cc dng kt hp khc nhau ca poly(sialate) c nu trong hnh 2.

Hnh 2. Cu trc poly(sialates) theo Davidovits [4]

Theo Fernandez-Jimenez and Palomo [6], t kt qu XRD ca cht kt dnh tro bay hot ha kim cho thy pha tinh th gc khng thay i theo phn ng ca cht kch hot. Mt s pick cho thy xut hin khong thch anh nhiu c th do thnh phn ht ct cn li mu. Thnh phn zeolite cng xut hin kt qu XRD di dng khong hydroxysodalite (Na4Al3Si3O12OH) v herschelite (NaAlSi2O6. 3H2O). Khi phn tch nh SEM cho thy trc khi hot ha, tro bay c dng hnh cu vi kch thc khc nhau v cha tinh th mulit v st. Sau khi hot ha, c mt s ht cu cha phn ng v gel aluminosilicat (c t l mol Si/Al=1.6-1.8 v Na/Al=0.46-0.68) trong va ch cha cht kch hot l NaOH. Khi cht kch hot c cha nc thy tinh th sn phm cui c hn vi t l monl Si/Al=2.7 v Na/Al=1.5.

Xie v Xi [18] nghin cu tro bay s dng cht kim kch hot l hn hp NaOH v thy tinh nc, qua kt qu phn tch nh SEM cho thy lng ln pha thy tinh tm thy cha phn ng vi thy tinh nc v vn ang c kt tinh. Theo kt qu phn tch XRD, c rt t pick cho thy sn phm phn ng ca tro bay. Krivenko v Kovalchuk [12], cng cho rng phn ng hot ha ca NaOH v thy tinh nc vi tro bay c hnh thnh mt s loi khong zeolite ging nh analcine v hydroxysodalite t l mol cao SiO2/ Al= 4.5-5

3. C TNH CA B TNG GEOPOLYMER

B tng geopolymer l b tng s dng cht kt dnh kim hot ha (cht kt dnh geopolymer). Trong qu trnh ch to, nc ch ng vai tr to tnh cng tc, khng tham gia to cu trc Geopolymer, khng tham gia phn ng ha hc m c th b loi ra trong qu trnh bo dng v sy (khng ging nh xi mng cn nc thy ha). Nhiu nghin cu cho rng, bo dng nhit cho b tng geopolymer s dng tro bay c hm lng vi thp s to cng cao, co kh t, t bin thp, chu n mn sunphat, chu axit tt v c th s dng trong nhiu ng dng c s h tng [9, 11].

V kh nng chu lc, B tng Geopolymer s dng tro bay c th cho cng cao sau vi gi phn ng kim (60-70 Mpa sau 24h) [5].

V tnh bn, b tng Geopolymer c cho l c tnh cht chu ha hc, chu nhit tt c trong iu kin mi trng thng v khc nghit [17]. Trng i hc Curtin kho st bn cng hp c sn t b tng geopolymer chu tc ng n mn cc mnh ca mi trng kh m ca t ln nhiu mui sunphat [11]. Kt lun a ra l b tng geopolymer c kh nng chu n mn ha hc cc tt v tt nht l kh nng chu axit.

Kh nng gn kt vi ct thp ca b tng geopolymer c nghin cu v so snh l tng ng hoc cao hn b tng xi mng sunphat [11]. Tuy nhin nhn chung geopolymer ch to t M ta cao lanh cn nhiu nc (lm tng l rng) v qu mm cho nhiu ng dng xy dng thc t. Dng nh rt t nghin cu s dng b tng geopolymer vi ct si.

4. TNH BN VNG V LI CH CA VIC S DNG B TNG GEOPOLYMER

Vic s dng b tng geopolymer trn c c cht kt dnh tro bay kim hot ha c kh nng gp phn gim hin tng nng dn ca tri t. Theo Davidoits [3], b tng geopolymer c kh nng gy hiu ng nh knh gim 26-45% so vi b tng xi mng thng thng. iu ny c th gii thch do: vic sn xut 1 tn xi mng thng to ra 0.55 tn CO2 t cc phn ng phn hy khong cacbonat v cng to ra khong 0.42 tn CO2 do t cc nhin liu cc bon, nh vy xp x 1 tn CO2 sinh ra khi sn xut 1 tn xi mng. Tuy nhin vic sn xut 1 tn cht kt dnh geopolymer t tro bay ch to ra khong 0.180 tn CO2 t s t chy nhin liu cc bon. Nh vy, so vi 1 tn CO2 sinh ra khi sn xut xi mng th sn xut cht kt dnh geopolymer thp hn gn 6 ln. Hay ni cch khc, c th sn xut ra lng cht kt dnh tng ln 6 ln cho pht trin h tng v xy dng vi cng lng kh CO2 thi ra mi trng [3].

Bn cnh , cht kt dnh geopolymer cng tn dng cc ph thi ca qu trnh sn xut cng nghip nh tro bay ca nh my nhit in; x l cao ca nh my luyn gang, thp; ... Cho nn vic s dng b tng geopolymer trong cng nghip xy dng cn c th mang li nhiu li ch khc nh: gim nguy c cht thi cng nghip v din tch bi cha cht thi, ci thin cht lng tui di ngy ca b tng(co ngt kh rt thp, t bin thp, kh nng chng n mn sunphat v axit rt tt), t gim chi ph u t v bo tr cc kt cu s dng b tng geopolymer,...

V mt kinh t, gi thnh ca 1 tn tro bay/ x ch bng mt phn nh so vi gi ca 1 tn xi mng. V vy sau khi tnh c gi ca dung dch kim kch hot th gi ca b tng geopolymer tro bay s thp hn khong 10-30% so vi gi ca b tng xi mng [3].

5. CC NG DNG THC TIN

Theo Davidovits [3] thng k cc dng ng dng cht kt dnh geopolymer ni chung c th nh sau:

Tm kt cu g chng chy

Tm tng v panel cch in

Sn xut nhn to trang tr

Tm panel bt cch nhit

Vt liu xy dng th

Gch khng nung

Kt cu chu la

Kt cu chng sc nhit

ng dng lm khun c nhm

B tng v cht kt dnh geopolymer

Vt liu cn la v gia c/ sa cha

Vt liu chng chy cng ngh cao dng trong by bay hoc t

Vt liu nha cng ngh cao

M, ng dng ch yu ca cht kt dnh geopolymer l sn xut xi mng geopolymer ng rn nhanh (Pyrament Blended Cement- PBC). PBC c nghin cu sn xut v ng dng trong cc sn bay qun s t nhng nm 1985. Sau PBC c dng nhiu trong sa cha ng bng b tng, sn nh cng nghip, ng cao tc. Loi xi mng ny c th t cng 20 Mpa sau 4-6h ng rn. Mt loi xi mng geopolymer khc cng c nghin cu s dng l xi mng geopolymer bn axit. Nm 1997, cng ty Zeo tech corp thng mi ha thnh sn phm b tng geopolymer bn axit. Sn phm ny c dng nhiu trong cc nh my ha cht v thc phm.

c, b tng geopolymer v ang ng dng trong thc tin nh: cc thanh t vt c sn, ng ng cng v cc loi cu kin b tng c sn khc trong xy dng. Vi c tnh tt nht ca cc kt cu c sn l cho cng tui sm cao sau khi c bo dng hi nc hoc dng h nhit [11, 13]. Trong bo co v qu trnh sn xut cc thanh t vt b tng geopolymer trn c s geopolymer tro bay, Palomo et al. cho rng cc kt cu b tng geopolymer c th d dng c sn xut bng nhng cng ngh sn xut b tng hin ti m khng cn phi thay i ln no. Mt s nh nghin cu khc cng sn xut cc sn phm ng cng b tng geopolymer ct thp c sn c ng knh t 375-1800mm; cc cng hp b tng geopolymer ct thp c kch thc 1200x600x1200 mm [11]. Kt qu nghin cu cho thy, kh nng chu mi trng nc thi xm thc rt tt v tng ng sn phm b tng xi mng.

B tng geopolymer c hot tnh kim cng c thng mi ha c vi nhn hiu kinh doanh E-Crete(TM). E-Crete c ti ch t tro bay v x l cao cng vi cc cht hot tnh kim thch hp v hin c sn dng c sn v trn sn. Cc sn phm c sn ca E-crete ch yu nh: cc panel c sn, hnh 3, 4; cc ng, np v cng; cng hp; b x t hoi; h thu rc, gch lt va h; tm p lt trang tr hoc cch m; ... [19].

Vit nam, mi ch c 1 dng sn phm thng mi c ngun gc t b tng geopolymer l gch t khng nung. Tuy nhin cha c s dng rng ri trong cc cng trnh xy dng. c mt s nghin cu bc u v b tng geopolymer nh b tng chu la khng xi mng ca nhm nghin cu Vin Vt liu Xy dng [20]. BTCL khng xi mng da trn lin kt rho- alumina tn thng phm l alphabond 300, so vi BTCL t xi mng l cng ngh ch to n gin, thi gian s dng ca vt liu ny tng, tnh cht c nhit tt nh tng nhit bin dng di ti trng v tng bn un nhit cao. Nhm nghin cu ch to thnh cng BTCL khng xi mng ng dng th vo thc t. Mt nghin cu khc v ng dng cht kt dnh geopolymer l sn xut vt liu khng nung t ph thi tro bay v x l cao cng c thc

hin nm 2011. Kt qu nghin cu xy dng c quy trnh sn xut vt liu gch block b

tng geopolymer c cng nn t >10 Mpa, c gi thnh r hn gch block b tng xi mng

ct liu khong 15% [10].

Hnh 3. B tng E-Crete 25MPa lt nn ng cao tc Westgate,Cng Melbourne, Victoria, c.

Hnh 4. Cc tm panel b tng E-Crete 55Mpa c sn Cu Ph Salmon, Cng Melbourne, Victoria, c.

6. NHNG HN CH KHI S DNG B TNG GEOPOLYMER

Ngoi tr cc u im, b tng geopolymer vn c cho l kh c th ph bin trn th trng hin nay. L do chnh cho iu ny l phn ln cc nh my xi mng cn lo ngi v nguy c st gim li nhun khi u t [12].

Trn quan im cng nghip xy dng, xi mng xanh mi ch c cp n nh mt khi nim ch cha c chng minh bng thc tin cng ngh [5]. Vn cn c s tranh ci v kh nng gim thiu kh CO2 v tnh kinh t khi xem xt n gi thnh v s tn ti ca cht hot ha kim trong b tng geopolymer. R rng l c s nguy him nht nh khi s dng dung dch kim mnh v dung dch kim mnh cng i hi qu trnh sn xut b tng phc tp hn, iu ny dn n gia tng tiu th nng lng cng nh pht sinh hiu ng nh knh [7]. Trn thc t, cn c t nghin cu v cc tnh cht vt l ca b tng geopolymer, mc d iu ny kh phc tp v cn thit thc hn b tng thng. V d nh: qu trnh phn ng polyme ha chu nh hng rt nhiu bi nhit v thng i hi phi bo dng nhit cao cng vi s kim sot nghim ngt ch nhit [9, 11]. Kh nng pht thi cc cht kim kch hot vo mi trng nc v khng kh khi s dng sn phm b tng geopolymer.

7. KT LUN

Ngnh cng nghip xy dng v b tng v ang s dng lng ln ngun ti nguyn v nng lng. V vy, i hi phi c trch nhim gim thiu cc tc ng mi trng bng nhng hnh ng c th. Mt th k mi ca cng ngh b tng bt u vi b tng geopolymer vi lng pht thi kh CO2 thp hn b tng thng, mang li nhiu u im trong vic tng bn v kh nng chng n mn, c cng cao cho cc kt cu.

Thc t cho thy, vic s dng b tng gepolymer sn xut cc cu kin b tng c sn l rt ph hp, cn c u t nghin cu v m rng cc ng dng.

Cn tip tc nghin cu c tnh ca b tng geopolymer c th thng mi ha cc sn phm quy m ln v pht trin trn th trng.

Cha c nhiu nghin cu v vi cu trc ca cht kt dnh geopolymer, vng tip xc v kh nng gn kt gia cht kt dnh geopolymer vi b mt ht ct liu (c bit l cc ct liu ti ch t ph thi ln nhiu tp cht) trong b tng geopolymer.

TI LIU THAM KHO

Ting vit 10. Hoan Nguyn Vn (2012), Nghin cu sn xut vt liu khng nung t ph thi tro bay v x l cao

trn c s cht kt dnh geopolyme. (Vin Vt liu Xy dng).

19. Ximangvn (2011) B tng geopolymer Mt sn phm thng mi.

20. Ximangvn (2012) Ch to thnh cng B tng chu la khng xi mng.

Ting Anh 1. Boutterin C.& Davidovits J. (1988) Geopolymeric Cross-Linking (LTGS) and Building materials.

Geopolymer ' 88 Vol.1:pp. 79-88. 2. Chao Li, Sun Henghu& Li Longtu (2010) A review: The comparison between alkali-activated slag (Si

+Ca) and metakaolin (Si +Al) cements. Cement and Concrete Research Vol. 40:13411349. 3. Davidovits J. (2002) Environmentally Driven Geopolymer Cement Applications. Geopolymer

Institute, 02100 Saint-Quentin, France 4. Davidovits J. (2005) Geopolymer chemistry and sustainable development. The poly(sialate)

terminology: a very useful and simple model for the promotion and understanding of green-chemistry. in In: Proceedings of 2005 geopolymere conference, pp 9-15.

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GEOPOLYMER CONCRETE-

ACHIEVEMENTS, PROPERTIES AND RECENT APPLICATIONS NCS. ThS. Tng Tn Kin*1, TS. L Trung Thnh3 , ThS. Phm Th Vinh Lanh2 1 Department of Building materials, National University of Civil Engineering of Vietnam,

kientt@nuce.edu.vn, +84 977966357 2 The College of Construction technical No 1 3 Ministry of Construction of Vietnam

ABSTRACT:

Geopolymer results from the reaction of a source material that is rich in silica and alumina with alkaline liquid. It is essentially cement free concrete. This material is being studied extensively and shows promise as a greener substitute for ordinary Portland cement concrete in some applications. It has been found that geopolymer concrete has good engineering properties with a reduced global warming potential resulting from the replacement of ordinary Portland cement. This research presents a brief history, properties of geopolymer concrete as well as recent applications of geopolymer technology in the world and in Vietnam, it also gives recommendations researches on geopolymer concrete (GC) technology for sustainable construction in Vietnam.

KETWORDS: Geopolymer, geopolymer concrete, cementlss concrete, Sustainable construction