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Nghien CLFU nang cao chat lipgng be tong khi khong chu'ng ap SLP dung cho xa- dipng 6> Viet Nam
Ngay nhan bai: 20/9/2014 Ngay sCra bai: 5/10/2014 Ngay chap nhan dang: 10/10/2014
Nguyen Trpng Lam, Hoang Van Tien, Nguyin Van Tuan
T O M TAT:
Be tong khi khong chting ap (NAAC) la loai vat lieu khong nung nhe co nhieu tiem nang phat trien nhc( co khoi liidng the tich nho, kha nang each am, each nhiet t6t, cong nghe san xuat don gian, vdn dau tit ban dau thap va tiet kiem nguyen heu. Tuy nhi^n, cho den nay trong san xuSt v i sti dung loai vat lieu nay cf Viet Nam van con mot so han che nhil- cddng do thap, d6 co ngot I6n, dp hiit niicfc cao va chat Itiong kem on dinh, v.v... Viec nghien cdu khac phuc nhiing han che tren gulp nang cao hieu qua sii dung NAAC nham dila loai vat lieu nay vao sii dung rang rai trong xay diing d Viet Nam la rat can thiet.
Bai bao nay trinh bay mpt s6 kft qua nghiSn cilu nham cai thien mot so tinh chat cua NAAC, Ket qua nghien cilu cho thay, khi s\i dung ket hpp phu gia sieu deo va phu gia polime tai phan tan, mpt so tinh chat cila NAAC co the dilOc cai thien so vdi mau doi chiing khong sil dung phu gia, nhd cildng dp nen tang 52%, ciftJng dp uon tang 360%, dp hut nilcic bao hoa giam 46,6% va he so hiit nil6c mao dan giam 58%,
Ttf khoa: B^ t6ngkhi kh6ng chtfng dp; d6 hiit nildc bao h6a; he so hut niloic mao dan.
ABSTRACT
Non-Autoclaved Aerated Concrete (NAAC) is a great potential unburned lightweight material with a low density, good acoustic insulation, good thermal insulation, simple production technology, low initial capital investment and saving in materials However, some disadvantages of NAAC, i.e. low strength, high shinkage, high water absorption and unstable quality, still cause the limitations for the use of this material in Vietnam.
This paper presents some aspects for improving on the properties of NAAC in order to compensate the its limitations and put this material into widespread use in construction in Vietnam, The experimental results show that, compared to control samples without admixtures, the addition of a combination of superplasticizer and redispersible polymer powders increased the compresive strength of NAAC by up to 52%, the flexural strength by up to 360%, and reduced the water absorption by down to 37%, the capillary water absorption coefficient by down to 58%.
Keywords: Non-autoclaved aerated concrete; water absorption at saturation;
capillary water absorption coefficient.
Th-S Nguyen Trong Lam,
Khoa Vat lieu Xay dilng, Tnl6ng Dai hpc Xay diing NCS Hoang Van Tien,
Cong ty CP Dau til Xay dilng va Be tong Vinh Tuy - UDIC TS Nguyen Van TuSn
Khoa Vat li^u Xay dilng, Trilcfng Dai hoc Xay dilng
1 . G i d i thieu
Be t o n g khi khong chUng ap (NAAC) la loai vat li^u khong nung nhe c6 nhieu t i e m nang phat tnen nh6 co khoi lUOng the tich nho, kha nang each am, each nhiet tot, cong n g h | sSn xuat d a n gian, von dau tiT ban 3hu t h a p va tiet ki§m nguyen lieu,Tuynhi#n, cho den nay trong san xuat va sii dung loai vat lieu nay 6 Vi§t Nam v§n con mpt so t o n tai nhClng nhupc diem nhif hien tUpng khoi xay NAAC bj tham va bi nilt, Hien t u o n g nay xay ra do NAAC co kha nang hut nudc I6n, cUdng do t h a p va bien doi the tich khi do am thay doi. NhQng t o n tai nay lam giam hieu qua sil dung cua NAAC trong xay dung d V i e t Nam, Oe giai quyet nhtlng van de neu tren cua NAAC can nghien cilu nang cao cu'dng dp va giam do hut nUdc ciia NAAC.
Thuc te cho thay rang cac ti'nh chat cila be t o n g khi phu thuoc chinh vao cau true cua no, Cau t n i c cua be t o n g khi t h o n g thu'dng g6m hai phan la 16 rong va phan vach ngan giu'a eac 16 rong dang t o ong. Lo rong cila be tong khi g o m hai he t h o n g cau true rong do la eac 16 rong dang t o ong hinh thanh do chat tao khi sinh ra trong qua trlnh p h o n g n d va cae 16 rong nho dUpc tao nen tir cac 16 rong gel va h | t h 6 n g m a o q u e i n n a m t r o n g vach ngan gifia cac 16 rong I6n [1-3].Tinh chat cila be t 6 n g khi phu thuoe ehu yeu vao eUdng do vach ngan giiJa cac 16 rong dang t o ong cung n h i l cau true vach ngan va cau true rong cOa bk t 6 n g [2-3]. Trong khi citdng do eua be t o n g khf phu thupe chCi yeu vao cu'dng d p vach ngan giUa cac 16 rong, hinh dang va kich thu'dc t r u n g binh eua 16 rong cung n h u sU phan bo eCia 16 r6ng trong be t o n g thl d6 hut nUdc c phu thupe vao cau true ronq v.
16 r6ng.
Ooi vdi b e l o n g khi, d.i , , trinh p h o n g nd dien ra thuar, d u n g t;^ le nUdc so v6i t o n g han ran (N/R) ldn. Bdi v | y , trong qu
ja be t o n g khi t i n h chat cua 1 bao cho qua
"^ti, t h u d n g sir i^cfngvatiieu trinh r^n chkc luong nudc dU thCia bay hoi tao nen r i . i > •
, ' I r • ICM <^dc lo rono mao quan t r o n g vach ngan, lam g i ^ m d n rt"
I c h 3 c e O a v a c h n g a n , g i a m c u 6 n g a a v & t ? " i?-
goaieiKllQ^i 11-2014
Bkng 1. Tfnh chat k^ thuSt cOa xi mang sCf d u n g trong nghien cCfu
Ti'nh ch^t Lirang sdt sdng 0,09mm Li/ong nu'dc ti&u chuan Thdi gian bSt dau dong ket Thdi gian ket thuc dong ket Cu'dng 36 n^n 3 ngay Cudng d o n^n 28 nghy Khoi luong rieng
D t f n v i
% %
Phut PhCit MPa MPa g/cm^
Ketqu&
4,2 27,0 150 240 25 45 3,05
PhUtfng phap thuT TCVN 4030-2003 TCVN 6017-1995 TCVN 6017-1995 TCVN 6017-1995 TCVN 6016-1995 TCVN 6016-1995 TCVN 4030-2003
BSng 2. Tinh chat ky thuat cu Tinh chat Lu'ong CaO hoat tinh T6C do t o i Nhiet do toi, °C Lydng sdt sang 0,09mm Kh6i luong ri^ng
bpt voi song sir d y n g trong nghien cilu D m t v i
phut
%
=C g/cm^
%
Ket qud 83,5
9,5 68 7,9 2,79
Phyong phap thiT TCVN 2231-1989 T C V N 2 2 3 M 9 8 9 TCVN 2231-1989 TCVN 4030-2003 TCVN 4030-2003
Bdng 3.Thdnh phan hdaeua tro bay s i l d y n g trong nghien eClu Thdnh phan
Hhrr\ lu'png, % SiO,
58,38 A I J O J
25,12 feiOi
7,01 CaO
0,84 MgO
0,7 NajO
0.3 K2O
3,28 MKN
5,29
Bing 4.Tinh chat ky thuat cua tro bay Tinh chat
Lu'ong sot sang 0,09mm Kh6i luong ri§ng Kh6i lu'ong t h e tich xop
Ddn vj
g/cm*
%
kg/m^
K e t q u i
0,5 2,15 968
Phu'ong phap thtT
TCVN 4030-2003 TCVN 4030-2003 TCVN 340-1986
hiit nude cua be tdng khf, Vi the, viec giam ty le N/R trong khi van d a m bdo dp nhdt cua hon hap Vila hop ly de qua trinh phong n d dien ra thuan loi se han che hinh thanh cac 16 rong mao qudn va cac mang lUdi 16 r6ng t h o n g nhau, cdi thien d o dac chdc cua vdeh ngan, tang cudng dp va giam do hut nUdc cua be tdng khi',
Vdi muc dieh gidm ty le N/R, nhdm nghien cilu lUa chpn sir d u n g phu gia sieu deo (PGSD) de gi3m lu'png d u n g nUdc md van ddm bao d p nhdt cua hon hpp be t o n g , Ben canh do, de g i d m d d h u t n u d c d e t d i sil d u n g t h e m p h u gia polime tai phan tan (PGPL) de nang cao chat lupng cua NAAC.
2. V|it lieu SIJT dung va phUdng phap nghiin cihi
2 . 1 . V a t i i f u sijrdung
Vdt lieu sil d u n g trong nghien cdu g o m : Xi mang PC40 Bilt Son, bdt vdi song, tro tuyen Phd Lai, chat tao rong bot n h d m , PGSD va PGPL.
Tinh chat ky thuat va t h d n h phan hda cua vat lieu sil d u n g duoc trlnh b i y trong BSng 1 den B i n g 4
- Bpt n h 6 m
D l tai s i l d y n g bpt nh6m vPi ham lupng n h d m kim loai dat 86% vd h i so sdn lupng 1050
lit khf hidrP/l kg bpt nhdm - Phy gia sieu deo
PGSD sir d u n g cho be tong khi ngoai kha nang giam nUdc cao edn phdi dam bdo khdng pha v d bot khi, theo [4] PGSD phu hop cho be t d n g khi la PGSD the he 3 goc polycarboxylate.
Oe tai chpn PGSD Sika Viscocrete 3000-20, day la loai PGSD the he mdi nhat cua Sika co kha nang giam nUdecao.
- Phy gia polime tai phan tan PGPL sir d u n g la bot polime tai phan tan Vinnapas ciia hang Wacker, Do dUpc tao thanh bdi qua trlnh say phun hon hop cac chat phan tan polime 6 t h e nhu t u o n g nen khi tron vao trong be tong cac hat bpt polime tan ra va gidi phdng cac hat phan tan neng le va t r d lai trang thai ban dau, Chfnh mang polime tao thanh tU cac hat tai phan tan cd vai trd n h u m d t chat ket dfnh b o sung va cdi thien t i n h chat 16 rong cua be t d n g khL
2.2. PhUdng phap va vat lieu nghien cihi 2.2.7. Phuang phdp nghien cdu Be tdi sir d y n g cdc phuong phap tieu chuan de xac dinh eac tfnh chat cua vat lieu si£ d u n g va xac dinh khoi lUpng t h e tfch, cudng dd nen, cudng d o uon cua NAAC (TCVN 9030:2011),
d Viet Nam hien nay chUa cd du cdc tieu chuan neng de xac d m h dp hut nudc bao hda va he so hut nUdc mao dan ciia NAAC. Do dd, tac gid sCl dung tieu ehuan TCVN 3113:1993 (tJeu chuan xac dinh dp hut nUdc ciia be tong ndng) de xdc djnh dp h i i t nude ciia NAAC vd tieu chuan TCVN 9028 2011 (tieu chuan xac dinh he sd hut nudc mao dan cua vda sil dung cho be tong khi) de xac djnh he so hiit nUdc mao dSn ciia NAAC.
De tinh toan cSp phoi, tdc gia sit d y n g phuong phap tfnh toan ket hdp vdi thUc nghiem xdc dinh theo khoi lUpng the tich kho cua A.P,Baranov[1].
2 2.2. Phuang phdp chudn bi mdu Sil dung mau cd kich thudc 100x100x100 m m de xac djnh khdi lupng the tich, cUdng d p nen va d o hut nUdc, mau 100x100x400 de xac dinh cUdng d o uon va mau cd kich thUdc 40x40x160 m m d l xac djnh he so hut nUdc mao dan. So lupng mau k i l m tra cac chi tieu khong it hOn 3 mau tren 1 cap phoi,
3. Clip phoi be tong kht khong ch Ung ^p Phuang phap tinh cap phoi eiia A,P.Baranov [1] dUa tren nguyen tSc ddm bdo khoi luong t h l tfch kho cho trudc va dp chay ciia hon hpp vda phai p h ^ hpp de qua trinh ph6ng nd di&n ra thudn lot nhat. Bdi vay, khi sil d y n g PGSD phdi dieu chinh lupng dung nudc sao cho d p chay ciia hon hap vda khong ddi, khi d o luang dCing chat tao rong cung phdi tfnh toan lai. Do dd, khi sil d u n g p h u gia phdi tinh toan lai cap phoi.
Trong be t o n g khi, chat k i t dinh, thanh phan silic va chat tao rong la eac thanh phan chi'nh. Trong de tai, thanh phan silic sil d y n g la tro tuyen Pha Lai, chat k i t dinh sir d u n g Id xi mdng PC40 va bot vol sdng, trong dd lUOng dung vol lay bang 10% lUpng diing xi mang.
Vdi muc tieu hudng tdi san pham NAAC dat cUdng dd nen ldn hon hoac bdng 5MPa, d l tai ehpn ioai NAAC cd khoi lupng t h l tich khd 700 kg/m3 de n g h i i n cdu.
3.1. Tinh toan c£p phoi khi chua co phu gia Odi vdi NAAC chUa sir dung phu gia cd khoi luong the tieh khd 700 kg/m=, gia tri N/R chon sao cho dp chay ciia hon hop vUd t h i nghiem bang nhdt ke Suttard dat 22 cm [1],
Theo k i t qua tren Hinh 1, de d d chdy dat 22 cm thi N/R = 0,474 Td do tinh dupc cdp ph6i cho I m ' NAAC cd khoi luong the tich kho 700 k g / m ' khi chUa sd dung phu gia n h u Bdng 5,
Bang 5, Cap phdi cho I m ' NAAC cd khdi lUOng t h l tich khd 700 k g / m ' khi chda sir d y n g phu gia
XM, kq 277
Vdi, kq 28
Tro bay, kg
304 Nudc,
lit 289
Bdt n h d m , kq 0,67 3.2. Tinh toan cap phoi khi co sil dung phu gia sidu ddo v^ phu gia polime t^i phSn tan
Khac vdi be t d n g t h u d n g , vdi be t d n g khi, khi sif dung PGSD se phai tinh todn lai hoan
11.2014 smtifKiioi 9 3
toan cap phoi, do khi sif dung PGSD Idm thay doi dang ke t^ le N/R dan d i n phdi tinh todn lai d d rdng vd luang dung chat tao r6ng.
- Xdc dinh lUOng dting PGSD:
l u o n g dung PGSD dUoc xac dinh diia vao diem bao hda ciia loai PGSD sif dung, Oiem bao hda PGSD dUoc xac dinh dua tren quan he giCia dp chay ciia hon hap vda vd ham luang PGSD sir dung k i t hpp vdi quan sat hien tuang tach nudc cua hdn hop vCfa. TU k i t qud tren Hinh 2 cho thdy, khi t y le PGSD sd dung ldn hon 0,6%
thi hieu qud tang dp chdy ciia vda kem vd cd hien tupng tach nUdc. Bdi vay, diem bao hda ciia PGSD sd dung tUOng img vdi t^ I I la 0,6%.
TJIiPCPL,%
Ifinh 4 Tinmg quan giOs lirimg iiing phu gia polime tai phan tan va do chay cila vifa
cao cua nha san xuat, 3i ddnh gia dnh hudng eiia PGPL d i n tfnh chat eiia I>JAAC, lUpng dung PGPL dUdc khdo sdt t d 0,5-2,0% luang chat ket dinh. Khi sir dung PGPL, dp chay cua hdn hpp vQa gidm nhutig khdng nhieu (Hlnh 4). 8di vdy khi chi sCr dung PGPL khdng can d\eu chinh lai cap phoi.
Sau khi khdo sat vd xdc dmh luang dimg ciia cdc loai phu gia, cap phoi t h i nghiSm duac t i n h todn va t6ng hap trong Bdng 6.
4. Ket q u i nghiin cUu vk ban luan T i n h c h a t ciia NAAC dUOe n g h i e n cUu b a o
Hlnh 2 Anh hifftng ci}a lining dUng phu gia Sika Viscooete 3000-20(!en do chiy ciia v ^
MAT tfim Burii. % Kinh 3. Kha nang gilm nUdc ciia phu gia sieu deo Sika Viscooete 3000-20
- Xac djnh khd nang gidm nddc cua PGSD Vdi lucmg dCing 0,6%, kha nang gidm nudc cua PGSD dupc xac dinh sao cho d p chdy cua h6n hop vda van dat 22 cm, TCr ket qud t r i n Hinh 3, khd ndng gidm nudc ciia phu gia Sika Viscocrete 3000-20 36\ vdi cap phoi sir dung Id 39,6%.
- Phu gia polime tdi phdn tdn:
LUcmg diing PGPL duac chon theo khuyen
g o m khdi lupng t h l tich kho, cddng d p n i n , cudng d p udn, d d hiit nddc bao hoa vd h i s6 hiit nddc mao dan. K i t qud t h i nghiem dUpc trinh b^y trong Bdng 7.
4 . 1 . Anh h u ^ g cOa phu gia 3§n cUifng dfi nen cua NAAC
Anh hudng cOa PGSD vd PGPL d i n cUimg dp nen eua NAAC dUpc t h l hien tren Htnh 5 vd Hinh 6, tif ket qud tren cho thdy:
Khi tang ham lUpng PGPL, cUdng dp nen cOa NAAC tang, tuy nhien mile tang Idn nhdt chi khodng 9%. Khi sir d u n g PGSD cudng dd n i n ciia NAAC tang ddng ke, khi ket hop PGSD vd PGPL cudng d p nen ciia NAAC cd the tdng d i n 54%. N h u vay, v l kh6i lUdng t h l tieh sdn pham NAAC ciia de tdi thupe nhom D700.
nhung cUdng d d nen dat c3p B5, tUong dUdng cap cUdng d p cua n h d m D l 100 theo tieu chuan V i l t Nam [5].
Kel qud tren dat dupe d o khi sCr dung PGSD cd the gidm den 39,6% lUpng nUde sif dung, d i l u nay cd the se lam gidm lUang nddc duthtfd, 1dm tdng d d ddc cdu triie ciia vach ngan giti:a cdc lo rong t o ong, bdi v|iy lam tang cudng dd nen ciia NAAC. Ben canh dd, PGPL ft dnh hudng d i n cUdng d p n i n do khdng cd kha nang gidm Bd
CP
1 2 3 4 5 6 7 8 9 10
ng 6 Cap phdi NAAC sif dung trong n g h i i n cUu T^ I f phu gia,
%
PGPL 0,0 0,5 1,0 1,5 2,0 0,0 0,5 1,0 1,5 2,0
PGSD 0,0 0,0 0,0 0,0 0,0 0,6 0,6 0,6 0,6 0,6
Xi mang,
kg 277 277 277 277 277 277 277 277 277 277
Voi, kg 28 28 28 28 28 28 28 28 28 28
Tro bay, kg 304 304 304 304 304 304 304 304 304 304
N i l d c lit 289 289 289 289 289 175 175 175 175 175
Bot nhdm,
kg 0,508 0,508 0,508 0,508 0.508 0,622 0,622 0,622 0,622 0,622
Phu gia, kg PGKN
0,00 1,52 3,05 4,58 6,10 0,00 1,52 3,05 4,58 6,10
PGSD 0,00 0,00 0,00 0,00 0,00 1,83 1,83 1,83 1,83 1,83 Bang 7 Tinh chat ciia NAAC nghien cdu
CP 1 2 3 4 5 6 7 8 9 10
KLTT, k g / m ' 711 718 728 733 740 722 730 740 744 748
CUimg do n i n , MPa 4,63 4,73 4,81 4,85 4,98 6,35 6,50 6,88 6,91 7,05
Cudng d d uon, MPa 0,20 0,36 0,44 0,45 0,46 0,79 0,86 0,89 0,91 0,92
D o hOt nudc,
%
41,64 34,12 32,61 31,15 30,13 24,39 23,50 23,10 22,85 22,23
H£ sfi hut nudc mao dSn, k g / m ^ p h u f - '
1,85 1,45 1,28 1.20 1,10 1,00 0,90 0,83 0,80 0,78
g4iBllillEIISl 11.2014
lupng nudc duthCfa trong NAAC.
6,» e,s ^
—
1.63 * 4,73 see ' 4 , 8 1G 9 I 7,05 4,ee
Hinh 5. Anh huflng cila PGPL den cu5ng do nen cja NAAC
CPOC J'.POPl ?OSD KiSD-:'J'OPL Hinh 6 Ci/Ong do n^n cua NAAC sildung PGPL vd PGSD
2 '
4"
'•8 o.e
3 w
f 050.7B
0 2 , . ^ oae
" 0 ^ o,se
0 4 4 0,91 •
'o,4S
dp uon cua NAAC co t h e tang d i n 4,6 lan so vdi CPDC. Ket qud nay ed dUdc n h d kha nang gidm lupng nude dU thifa cua PGSD vd khd nang tang lien k i t giCia eac phdn tir trong NAAC ciia PGPL.
4 . 3 . A n h h i ^ g cOa p h u g i a d e n d o h i i t nUdc b a o h o a cija NAAC
Anh hudng cua PGPL va PGSD d i n d d hut nude bao hoa ciia NAAC dupe the hien t r i n Hinh 9. Ket qud tren cho thay, khi sir d u n g 2%
PGPL cd t h l gidm dUOc 28% d d h i i t nUde bdo hoa cua NAAC vd khi sd d u n g 0,6% PGSD d o hut nUdc bao hda ciia NAAC gidm d i n 4 1 % . Ode b i l t khi sd d u n g k i t hap cd hai loai phu gia tren.
dd hdt nudc bdo hda ciia NAAC cd the gidm den 46,6% so vdi mau khdng sd d u n g phu gia, NhU vay, khi s d d u n g ket hop PGSD va PGPL se phdt huy duac h i l u qud t d n g hop (tdc d u n g tUong h6) eda hai loai phu gia nay vd mang lai hieu qud cao trong viec gidm d p hut nudc bao hoa ciia NAAC.
K i t qud tren ed dUoe do khi sir dung PGSD lam gidm ddng k l l U p n g n U d c sir dung dan d i n lam giam lUpng nudc dU thda trong be tdng khi. Chinh viee gidm dupe lUpng nUdc dU thifa se gidm 16 rong mao quan do nUdc dU thira bay hoi, Idm tdng dp dac eda vach ngdn giUa cac 16 rong khi vd tang ty le 16 rdng kin trong be tong khi. Bdi vay, khi sd d u n g PGSD lam gidm dp hilt nude ciia NAAC. Ben canh do, khi sir d u n g PGPL trong NAAC chdng se tdi phan tan tao ra cdc mang polime lam gidn doan cac 16 rong mao qudn va giam luong Id rong t h d n g nhau trong NAAC, dan den Idm gidm dd hut nudc ciia NAAC.
- • - P G P L - ^ P G S D - P L Hinh 7. Anh hirdng cds PGPL d^n cifcing do uon cua NAAC
/• '
oa
O.TS0 J „ . ^ 0,80
- l o i M - -nm
0,4J 0 , . ;
0,45
Hinh 8, CifSng do uon ciia NAAC sir dung PGPL va PGSD 4 . 2 . A n h h u d n g ciJa p h u g i a d i n c u d n g d d u o n ciia NAAC
Kel q u d cUdng d o uon cOa NAAC khi sif d u n g PGSD vd PGPL dUdc the hien tr§n Hinh 7 vd Hinh 8, t i f k i t qua tren eho thay PGPL dnh h u d n g dang ke d i n cudng dd u o n ciia NAAC, dac biet vdi trUdng h d p khdng sCr d u n g PGSD, ktii sif d u n g PGPL cUdng d p uon eiia NAAC cd t h l t a n g d i n 130% so vdi cap ph6i doi chdng (CPOC). Khi sir d u n g PGSD, cUdng dp udn ciia NAAC c6 t h e t a n g gan 4 lan so vdi CPDC. Bdc b ' - khi s d d u n g ket hop PGSD vdi PGPL, cddng
Hinh 9. Anh huifng cua PGPL va PGSD den do hilt nuac bao hoa cua NAAC
4.4. A n h h u d n g cua p h u gia d ^ n he so h u t nUdc m a o d a n cOa NAAC
Sir d u n g PGSD va PGPL Idm gidm ddng k l h& so b i l t nude mao dan cua NAAC, k i t qua tren Hinh 10 cho thdy, khi s d d u n g 2% PGPL eo the giam d i n 40.5% vd khi sd dung 0,6% PGSD cd the gidm d i n 46% he so hiit nUdc mao dan ciia NAAC, Khi sd d u n g PGPL ket hop vdi PGSD, h i sd hut nudc mao dan cua NAAC gidm den 58%.
Tuy n h i l n , t i f ket qud cudng d o uon va he so hut nudc mao dan cue NAAC cho thay, khi hdm luong PGPL Idn hem 1 %, t i n h chat cua NAAC van dUde cdi thien nhung mUc d o khdng n h i l u , bdi vay n i n dung PGPL vdi ham luong 1 % Id h i l u qud cd ve mat kinh t l vd ky thudt.
Cung t u o n g t u n h u d d i vdi d p hut nUdc bdo hda, h f so hdt nudc mao d i n eda NAAC gidm
H a n lu^ng PGPL, tt
Hinh 10, Anh hifdng cOa PGPL va PGSD den he so hiit nifdc mao dan ciia NAAC
manh khi sir d u n g PGSD vd PGPL d o d p dac cCia vdeh ngdn gida cac 16 rdng khi tang, lUdng 16 rong mao qudn gidm vd ty le 16 rong kin ciia NAAC tang.
5. Ket l u a n
Tren cd sd n g u y i n vat lieu sCr dung va dieu k i l n t h i nghiem da thUc h i | n , nghien cdu dua ra m d t so k i t luan sau:
1, Khi sd dung PGSD Sika Viscocrete 3000-20 ed the lam gidm den 39,6% lUpng d u n g nUdc, tdng cudng dp n i n (37%) vd cUdng dp udn (295%), gidm dp hut nUdc bdo hda (41%) vd gidm he so hut nUde mao dan (46%) eua NAAC.
Ham luong PGSD k h u y i n d i i n g Id 0,6% so vd^
chat ket dinh;
2. Khi sirdung PGPL cd the Idm gidm dp hut nUdc bdo hda (28%) vd he sd hut nude mao dan (40,5%), tdng cUdng d p uon (130%) nhUng tang khdng dang ke eUdng dd nen ciia NAAC. Hdm luang PGPL khuyen d u n g Id 1 % so vdi chat k i t dinh;
3, Khi sd dung k i t hop PGSD vd PGPL tao ra h i l u dng t u a n g h6 ciia hai loai p h u gia ndy, cd t h e tang eudng dd nen den 52%, cUdng d p udn tang den 360%, giam d p hut nUdc bdo hda (46,6%) vd gidm he so hut nude mao dan (58%) cua NAAC;
4. Sdn pham NAAC cua d l tdi dat n h d m D700, nhdng cUdng d o dat cap B5, tUcflig duong vdi cudng d o ciia nhom D l 100 theo t i ^ u chuan Viet Nam.
TAI LIEU THAM KHAO
1, Nguyen lan Quy, Nguyen Thien Ru§ (2000), "Cong nghe Belong Xi mang 1", NXB Xay di/ng
2. N, Narayanan, K Ramamurthy (2000), "Structure and properties of Aerated Concrete: A review". Cement & Concrete Composites, Vo[ 22, pp, 321-329.
3. N, Narayanan, K Ramamurthy (2000), 'Microstnidural investigations on Aerated Concrete", Cement and Concrete Research,Vol, 30, pp, 457-464,
4, Ewa Dziekan, et al (2001), "Infiuence of polymer superpfasticizers on the properties of Autodaved Aerated Concrete" Proceedings of the SIh Intematkmal Conference MI Autodaved Aerated Concrete'! 14-17 September 2001, Poland, pp. 207-214,
5, ICVN 9029:2011, "Be tong nhe - Gadi be long bot, be long khi ithong chung ap - Yeu cau ky Ihudf.
6. TCVN 9030:2011, "Be tong nhe - Gadi he tong bot, be long khi khong diUng i p - PhUOng phap ttiu".
