VAT
Ligu -
M6I TRU-ONG- KY
THUAT HA TANGNGHIEN Cl/U CHl TIEU O A N H G I A DO B^N CUA VU'A D A N
GACH 6 P LAT TRONG DI^U KIEN VIET NAM
TS. H O A N G M I N H O L T C , ThS. LE PHU-ONG LY
Vi$n KHCN Xay d y n g
Tbm tat: DO bin khi h$u cda vCra din la mdt ch!
tiiu ky thuit quan trong quyit djnh chit luong cda hi 6p lit, nhit Ii hi 6p lit mit ngoai. 0 cic nude chiu Au, dd bin khi hiu (thi hidn bing cudng dd bim dinh trong diiu ki$n tan bing) da duoc nghien cCru va quy djnh trong cic tiiu chuin ky thuit doi vdi vwa din.
Tuy nhiin, d niedc ta, dd bin cua vda dan trong diiu kiin khi hiu chwa duoc quan tim nghiin cCru mdt cich thiu dio. Bii bio niy trinh biy cic kit qui nghiin ciru phuong phip thi nghi$m vi thiit lip ch!
tiiu dinh gii dd bin cda vO/a din trong diiu kiin khi hiu Viit Nam. Cic nghiin cCru da tiin hinh cOng cho phip iua chpn cic dp phii vOa din thda man ydu ciu dd bin di di ra.
1 . 0 $ t v l n d l
Cbng tbc i p lat co vai tro quan trpng trong hoan thibn cbc ePng trinh xby dyng. Cae b l mbt i p , lat khbng nhdng d n d i m bao cac tinh nbng sd dyng, thim my ma cbn phai b i n vdng lau dai. Trong nhdng nam trude day, cbng tbc i p Ibt dypc thyc hipn theo phyong an mgeh day sd dyng h i va vda xi mbng.
cac b l mat i p lat theo phyong an nay, nhit la be mbt i p ben ngoai, thydng cb tuii thp khbng cao. Bong, bbp, ndt, tilt vbi,... la mbt s i bilu hibn suy giam chit lypng thydng thly. Trong vbng mydi nam trd Igi day, mpt s i logi vda dan dbc chung da b i t dau dupe sd dyng d nyde ta. Cbng tbc i p lat sd dyng logi vda nay dypc thyc hibn theo phyong phap mgeh mong. D i i vdi vda dan thi cbng theo phyong phbp mach mong chi tibu ky thubt quan trpng nhit lb cudng dp bam dinh.
Theo tieu chuin TCVN 336:2005, cudng dp bam dinh cua vda dan dupe dbnh gia thbng qua thi nghiem k6o giat t i hpp gach i p eb dp hut nude khbng Idn hon 0,2% dbn trbn nIn chuin kich thudc 300x250x10 mm, dype bao dydng trong cac dilu kien nhu: dilu kien tieu chuan nhiet dp (27± 2)°C, dp I m (50 ± 5)%; ngam nude d nhibt db (25 ± 2)°C vb lao hba nhiet d nhiet dp (70 t 2)''C. Cudng dp bam dinh sau 25 chu ky tan bSng c J.ng dype d l d p d i n
nhyng chi sd dyng de dbnh gia khi cb yeu c l u cua khach hang.
Co the thay ring cac dilu kibn ngam nude hay lao hba nhibt mdi chi mb phong tbc dpng cua tdng yeu to dpc Ibp tdi cydng dp bam dinh cua vda dbn va khbng dai dibn cho tbc dpng eiia thdi t i l t Chi tieu cudng dp bam dinh sau 25 chu ky tan bbng la chi tieu dbnh gib dp ben cua vda dan trong vung khi hau cP bang gia. Chi tibu nby ehua phu hop de dbnh gia cho vda dan trong dieu kien khi hbu Viet Nam.
Cac nghien edu ve bb tbng trong dilu kibn Vibt Nam [1, 6, 7, 8] da cho thay khi hbu nude ta vdi sy biln thibn v l nhibt dp, dp I m vb tbc dpng cua bdc xa mat trdi cb anh hudng to Idn d i n sy hinh thbnh vb phbt triln cbc tinh chit cua be tong va vda. Khbng tinh den cbc anh hudng nay cb the din d i n suy giam chit lupng, giam dp ben cua vbt libu va kit c l u cbng trinh. Ve co ban, cbc nghien edu [4, 5] cung cho thly vda dan ggeh i p lat su dyng chit kit dinh xi mbng tubn theo cac quy luat cua hb xi mang. Dieu do eb nghTa la chung cung chju anh hudng nhit dinh eiia eae y l u t i khi hau. Do do, vipe nghien edu db xuat va ap dyng chi tibu dbnh gib db b i n eiia vda dan gach i p lat, nhat la i p lat ngoai thIt trong dieu kien khi hbu Viet Nam la v l n de eb tinh thyc tibn cao.
Trong dieu kipn Vibt Nam, cac y l u t i khi hbu chinh anh hudng den dp ben cOa he bao g i m nhiet dp, dp am vb sy thay d i i co tinh chu ky cua nhibt dp va dp am. Cbc yeu t i tren khong chi anh hudng dbng ke dbn sy thuy hba, hinh thanh c l u true cua da xl mang va tinh chit, dp b i n eua polyme ma eon anh hydng den dp b i n cua he vda.
Dp am tbng Ibm tang ham lupng cac phbn td nyde trong c l u true hb xi mbng va polyme. Dudi tbc dyng eua nhibt db, d u true ehupi eua polyme va d u true da xi mbng cb the bj pha huy. Mpt s i nghibn edu [4] cho thay, tuy theo c l p phii va loai phy gia polyme, cydng dp bbm dinh cua vda dan trong dieu kibn ngbm nude dao dbng trong phgm vi 3-50%, trong dieu kibn ISo hoa nhiet suy giam 28-83%.
Tap chl KHCN Xay dung - so 4/2012
39
V A T LIEU - MOI T R U - O N G • KY THUAT HA T A N G
T i n suit va bien dO dao dpng nhiet dp eb anh hudng dbng k l d i n chit lypng bb tbng vb vda. Sy thay doi nhibt db trong thbng (gida cac mua) cb t h i cao hon so vdi trong ngby. Tuy nhien, sy thay d i i nby dibn ra vdi t i c db tuong d i i chbm, khbng mang tinh eye bp nbn npi dng suit phbt sinh do thay d i i nhibt dp khbng nguy hilm so vdi sy thay d i i trong ngby. Dilu kibn d n chu y la sy thay d i i dpt ngpt nhibt dp kit hpp vdi db I m trong ngby (ning, mua,...). Theo [7] cac thay d i i nay eb t h i d i n d i n hinh thbnh dng suit dang k l lam suy giam tinh chit cua be tPng mai nhu k i t d u chju tac dpng trye tilp eua khi hbu.
He i p lat bao g i m nhilu Idp vbt lieu vdi hb s i biln dang nhiet va bien dgng I m khac nhau. Dudi tac dpng cua khi hbu, nhiet dp, dp I m , gia trj bien dang khbc nhau eiia cac Idp vbt lieu se gay ra dng suit tgi vung tilp xue. Cac dng suit nby eP kha nbng thOe d l y sy hinh thanh cac vi nirt trong c l u true. Dudi tac dpng lau dai cua dng suit, cbc vi ndt eb the phbt triln ca v l s i lupng l l n kich thyde tgo eae v i t ndt. Tuy nhibn, dudi tbc dyng cua nhibt dp vb dp I m , qua trinh thuy hba eua xi mang tilp tyc diln ra. San phIm thuy hba hinh thbnh cb khS nbng l i p d l y cac lb ring vb vi ndt. Hai qua trinh nay dibn ra ding thdi vb quylt djnh tinh chit eua hb.
Nhy vby, khbng chi tac dyng eua y l u t i dpc lap lb yeu t i nhiet dp, yeu t i dp I m cb bnh hudng d i n he vda dan ma tac dPng ding thdi eua sy dao dPng nhibt dp - dp I m cung cb anh hydng ribng d i n hb.
Vby, d n cb mpt mP hinh thi nghibm phu hpp mb phong tbc dpng eiia sy dao dpng nhibt dp - dp I m cua thdi tilt d i n he vda dan.
Vibe sd dyng vda dbn trong i p lat eae cbng trinh xdy dyng db gbp phan dbng k l nang cao chit lypng be mat i p lat nbi ribng vb cbng tbc hoan thibn nbi chung. Tuy nhien nhu da phan tich d trbn, d l tuong thich vdi dilu kI6n Viet Nam, d n nghien edu dbnh gib dp b i n eua vda dan ggeh i p lat trong dilu kien khi hau Viet Nam. Bai bdo nay trinh bay cac kit qui nghien edu v l chi tieu danh gia dp bin cua vda dbn gach i p lat trong dieu kien Viet Nam, dupe thyc hien trong khuon k h i d l tai 01C-04/01-2006-02.
2. Vgt li^u va phirong phbp 2.1 V$t li^u su' dyng
Trong eae nghien edu v l vda dan da sd dyng xi mang But Son PCB 40 vdi eae tinh chit dupe trinh bay trong bang 1, eat vang Sbng LP vdi eae tinh chit dypc trinh bay trong bang 2 va cac phy gia polyme.
Bang 1. Tinh chit ky thuit cua xi mang But San PCB 40 STT
1
2
3 4
Chi tieu ky thu|t Cudng dp chju n6n a tuoi
- 3 ngby - 28 ngby Thdi gian ddng ket
- bat dlu - k i t thuc
Op nghien mjn, phin con Igi tren sang 0,08 mm
SO I n djnh the tich (xbc djnh theo phuong phap Le Chatelie)
Den vj
N/mm^
phut
%
mm
Gia tri 21 48
100 210 3,6 1 Biing 2. Cic ch! tiiu chit iu^ng cda cit
STT 1 2 3 4 5 6 7 8 9
Ten cac chi tieu Khli luyng ribng
Khoi lyyng t h i tich bao hoa nypc Khli luo'ng t h i tieh
Khli lupng thi tich xdp
Sbt, a sbt, cbc tap chit d dgng eye Hbm lupng byi, bun, sbt t>ln
Hbm luyng tgp chit hdu co (thd theo phyong phbp so mbu), mbu cua dung djeh trbn ebt khbng Idn hon
Opim
Kich thudc hgt Idn nhit, khbng Idn hon
Dvn vj g/cm' g/cm' g/cm^
kg/m'
-
%
% -
Gid trj 2,67 2,65 2,64 1470 Khbng
4,5 Mlu hai
0,3 0,315
Cbc phy gia polyme s d dyng trong nghien edu bao g i m polyme ding tnjng ngyng cua polyvinyl 40
acetate va ethylen copolyme dgng b$t tbi phan tbn (phy gia P11). polyme acrylic dgng nhO tuong nyde
Tap cW KHCN XSy dung - s6 4/2012
VAT LIgU - M 6 | TRU-dTNG - KY T H U A T HA T A N G
(phy gia P12), ethylen vinyl acetate biln tinh dgng bpt (phy gia PI 3) vb hydroxyethyl cellulose dgng bpt eb dP nhdt 35.000m.Pas d 20°C (phy gia P2).
Nin chuin dupe gia ePng tubn thu ybu d u eiia tieu chuin TCVN 7239:2003, cb kich thyde 300x250x10 mm. Ggeh m i u eb kich thudc (50x50) mm, cP dp hut nude nhd hon 0,2% theo khii lypng, mat dan vda khbng trbng men.
2.2 Phuvmg phip thi nghibm
Cydng dp bbm dinh dypc xbc djnh theo tieu chuin TCVN 336:2005 trong dilu kien tieu chuin, dilu kien ngam nude va dilu kien lao hba nhibt D i l u kibn thi nghiem nhiet I m dypc thilt Ibp tren co sd tham khbo cac dilu kien thi nghiem mP phdng thdi tilt Viet Nam [6, 7, 8] va cbc dilu kien eua he I p , lat
Mbt s i khbo sat cho thly nhiet db khbng khi vbo mua hb d nude ta khobng 35°C, dydi bnh hydng ciJa bdc xg mat trdi thi nhiet db mat ngobi cac k i t c l u cbng trinh cb t h i Ibn tdi 70°C. Db I m tuong d i i cua khbng khi cQng dao dPng mgnh, t d dudi 50% tdi bbo hba. M$t khac, cOng d n k l d i n tac dpng cua nude mua va nyde ngyng ty trbn b l mbt trong nhdng ngby nim. Do dd, d l mP phdng dilu kibn thdi tilt cb t h i lya chpn nhiet dd t i i da tdi 70°C vb dp I m trong dieu kien ngam nude. Chu ky thi nghiem nhiet I m bao
g i m s l y khb, nang nhibt dp vb ngam nude, giam nhiet dp vdi trinh ty nhu sau:
Sau khi tgo m i u tren t i m nIn theo TCVN 336:2005, m i u dupe lyu trong dilu kien tieu chuan trong 7 ngay;
- Sau 7 ngay, m i u dypc dya vao thi nghiem chu ky nhiet I m . Tiln hanh s l y m i u trong vbng 8 gid d nhiet dp 70°C;
- Lly m i u ra khoi tu sly, d l ngupi trong nhiet dp phPng thi nghiem trong vPng 1 gid;
Ngbm m i u trong nude 14 gid d nhiet dp 25±2°C;
- Vdt m i u ra va d l khP ty nhibn trong vbng 1 gid trong dilu kibn phbng thi nghiem trude khi Ibp Igi bydc s l y miu.
Ting thdi gian thi nghiem cho mpt chu ky nhiet I m la 24 gid.
3. K i t qua vb binh lugn
cac nghibn edu v l dp bin cua vda dbn dupe thyc hibn tgi Vien Chuyen nganh Be tbng bao g i m nghien edu anh hudng cua chu ky nhiet I m tdi cudng dp bam dinh cua vda dan, anh hudng ciJa lypng dOng xi mang, logi phy gia va hbm lupng phy gia d i n cudng d i bam dinh eua vda dan trong cbc dilu kien khac nhau. Cac thanh phin vda sd dyng trong nghien edu dupe trinh bay tgi bang 3.
Bing 3. C^c thanh phin vOa din sir dung trong thi nghiim Kyhieu
dp phli VI V2 V3 V4 V5 V6 V7 V8 V9 V10 V I I
Liryng dung v|t li$u, % (theo khli luvng) Xi mSng
30 40 40 40 40 40 40 40 40 40 50
c6t lieu 67,2 57,2 57,2 57,2 55,2 53,2 51,2 49,2 57,6 56,8 47,2
P11 2 2
- -
4 6 8 10
2 2 2
P12
- -
2
- - - - - - - -
P13
- - -
2
- - - - - - -
P21 0,8 0,8 0,8 0,8 0,8 0.8 0,8 0,8 0,4 1,2 0,8 3.1 Anh hudng cua dieu ki^n nhi^t am din cuimg
d^ bim dinh cua vOra
K h i nbng phat triln hay suy giim d e tinh c h i t ciJa vda dan phg thube nhilu vbo dilu kien bao dydng. Cbc nghien edu tap trung vao viec thilt Ibp cac thbng s i thi nghilm theo chu ky nhiet I m vb so sanh i n h hydng cua dilu kien chu ky nhiet I m tdi
cydng dp bam dinh eua vda so vdi d e dilu kien khbc.
Cudng dO bam dinh cua vda dan trong thi nghiem nhiet I m dype xbc djnh sau 5, 10, 15, 20 va 25 chu ky. K i t q u i thi nghiem vdi mpt s i d p phii dupe trinh bay tgi bing 4.
T9P chi KHCN XSy dung - s6 4/2012 41
VAT LIgU - MOI TRtfOrNG - KY T H U A T HA T A N G
Bang 4. Cwdng dp bSm dinh tieu chuin va sau dc chu ky nhiit am
d p phdi V I V2 V3 V4 V8
Cuvng dp bam dinh, N/mm' (phin tram suy giam cuimg dp bdm dinh, %) sau s6 chu ky nhi$t I m
0 1,12(0) 1,33(0) 1,59(0) 1,72(0) 2,49 (0)
5 0,52 (54) 0,64 (54) 0,86 (46) 0,67(61) 1,65(34)
10 0,47 (58) 0,53 (60) 0,86 (46) 0,64 (65) 0,80 (67)
15 0,47 (58) 0,50 (62) 0,85 (47) 0,62 (64)
0,60 (76)
20 0,46 (59) 0,50 (62) 0,85 (47) 0,62 (64) 0,60 (76)
25 0,46 (59) 0,50 (62) 0,85 (47) 0,62 (64) 0,60 (76)
K i t qua thi nghipm cho thly dudi tac dpng cua cac chu ky nhiet I m , cudng dp bbm dinh eua vda suy giam dbng k l nhit lb trong cac chu ky d l u (td 34%
d i n 61%). Tang ham lupng phy gia P11 td 2% Ibn 10% cho phbp hgn c h l mde suy giam cudng dp bbm dinh d eae chu ky d l u , nhung Ibm tbng t i e db suy giam d eae chu ky sau... Cbc thi nghipm cho thly mde dp anh hudng eiia chu ky nhiet I m din cudng dp bam dinh phy thupc vdo ban chit va lypng dung eua phy gia polyme. Ban chit hba eua phy gia quylt djnh mde dp bin vdng eua lien k i t dudi tbc dpng tuong h i eua nhibt dp va dp I m theo chu ky. CP t h i thly ring, vdi eting lupng dung, mac du vda dan vdi phy gia P12 eb cudng dp tieu chuin nhb hon vda dan vdi phy gia PI 3 nhung cydng dp sau chu ky nhiet I m lai cao hon. Do dP, chi tieu cudng dp vda dan sau chu ky nhiet I m cho phbp dbnh gia chuin xac hon tac ding tuong ho eua nhibt dp va d i I m tdi hb i p lat. Nhin chung, mde dp suy giam cudng dp bam dinh i n djnh sau 15 - 20 chu ky (vdi phy gia PI 2 va PI 3, mde giam cudng dp bam dinh tiln d i n i n djnh sdm hon - sau 10 chu ky). Do dP, cb t h i sd dyng cudng dp bam dinh sau 20 chu ky lam chi tibu dbnh gia. Trong cac nghibn edu tilp theo, cudng db bbm dinh trong dilu kibn nhiet I m dupe xac djnh sau 20 chu ky thi nghiem.
Tieu chuin Viet Nam TCVN 336:2005 eOng nhy tieu chuin chau Au EN 12004 quy djnh cudng dO bam dinh trong cac dieu kien thi nghibm khbng nhi hon 0,5N/mm^. Gia trj nby da dupe phan tich va lya chpn dam bao cho hp vat lieu i p lat lam viec on dinh, b i n vdng trong dieu ki6n thyc t l . Quy chuin gia trj cudng db bam dinh eua vda dbn sau 20 chu k^ nhiet I m , mP phong tbc dpng cua khi hbu d i n he vda dbn, cb t h i dya tren cac gia tri nby.
Qua cac phdn tieh tren, cP t h i d l xult chi tibu dam bao db b i n Ibu eiia vda dan cho hb i p tyPng ngoai la gia trj cydng dp bam dinh sau 20 chu kjf nhibt I m khbng nho hon 0,5N/mm^. Mde chi tibu nby dupe sd dyng de lya chon thbnh phin phu hpp cua vda dbn.
3.2 Anh hirdng cua v$t li^u sir dung tdi cudng dp bim dinh cua vira dan trong cic dieu ki?n khic nhau
Anh hudng eiia vat libu sd dyng bao gom logi vb lypng dung phy gia polime, lupng dOng xi mang tdi cudng dp bam dinh dupe danh gib trong tdng dieu kien bao dudng eu t h i nhlm xac djnh mde dp dpc Ibp eua cbc dilu kipn thi nghiem va xac djnh phuong an sd dyng hpp ly.
K i t qua thi nghibm cudng db bam dinh cua vda sd dyng cbc loai phy gia khac nhau vdi cung ty le 2%
dypc trinh bay trong bang 5.
Bang 5. /inh hudng cua lo^i phu gia ting dinh den cwdng dp bim dinh cua vCra din d p phdi
V I V2 V3 V4
Cydng dp bam dinh, N/mm^(suy giam cuvng dp bam dinh, %) trong cac diiu kipn
Tieu chuin 1,12(0) 1,33(0) 1,59(0) 1.72(0)
Ngam nyde 0,46 (59) 1,08(19) 1,08(32) 1,44(16)
Lao hoa nhift 0.92(18) 0,51 (62) 0,88 (45) 1,42(17)
Nhift im 0.46 (59) 0.50 (62) 0.85 (47) 0,62 (64)
K i t q u i thi nghiem cho thly i n h hudng eua logi nhiet, vdi cung ty le sd dyng PI3 cb hieu q u i tbng phy gig tang dinh d i n k h i nang bam dinh eua vda dinh cao n h i t Polimer P13 la s i n phIm eiia qua trinh trong d c dilu kiln thi nghiem la r I t khac nhau. Trong tmng hpp nhO tuong vdi ham lypng vinyl acetate cao eie dilu kibn tieu chuin. bao hba nude vb lao hoa (60 - 90%) nen b i n nhiet, bin nude. Nhyng sau cbc
42 T9P Chi KHCN XSy dung - so 4/2012
V A T U f U - MOI TRU-ONG - KY T H U A T HA T A N G
chu ky nhiet I m mde dp t i n thIt cudng dp bam dinh len d i n tren 60%. Phy gia P11 cb khoang nhiet dp lam viec khbng Idn hon 60''C, nbn b i n trong dilu kibn ngbm nyde nhung khbng b i n trong dilu kibn lao hba nhibt. Trong dilu kien nhiet I m mde dp suy giam cudng dp bbm dinh len den tren 60%. Phu gia PI2 gie acrylic mbc du cP mde dp suy giam cudng dp bbm dinh trong dilu kien ngam nude va lao hba nhiet cao hon so vdi P11 va P13 nhung trong dilu kien nhiet I m , mde dp suy giam cudng dp bam dinh chi d mde 47%, t i t hon so vdi P11 va PI3. Qua day, cb t h i thly ring cydng dp bbm dinh cao d cac dieu kibn tieu chuin, ngbm nude hay lao hba nhlpt chya t h i d i m bio cydng dp bbm dinh trong dieu kibn nhiet I m . Muc dp suy giim cudng dp bbm dinh trong cac dilu kien khac nhau phy thuPc rIt nhilu vdo ban chit eiia
phy gia. Do db, vibe lya chpn logi phy gia phu hpp se dem lai hibu qua cao cho cac s i n pham vda dbn.
Anh hudng cua hbm lupng phy gia tang dinh d i n cudng dp bbm dinh trong cae dieu kien thi nghiem dype khao s i t tren cac c l p phii V2, V5, V6, V7, V8.
K i t q u i (bang 6) cho thly khi tang hbm lupng phu gia P11, cudng dp bbm dinh d dilu kibn tieu chuan cua vda dbn tang dang ke trong khoang td 2% len 4%, cbn khi tang t d 4% d i n 10% phy gia P11 cydng dp bbm dinh eb tbng nhyng khbng dbng k l so vdi ty lb tang phy gia. Trong cac dilu kibn ngbm nyde, lao hba nhiet, nhiet I m , cydng dp bam dinh giam khi ham lypng P11 tang trbn 4%. Cbc thi nghibm trong dilu kien nhiet I m v i n cho thly day la dieu kien thi nghiem khlc nghiet hon.
Bing 6. Anh hwdng cua him Iwqmg phu gia din cwdng dd bim dinh cua vu'a dSn d p phli
V I V2 V5 V6 V7 V8 V9 V10 V I I
Cydng dp bam dinh, N/mm^(suy giam cudng dp bam dinh, %) trong Ceic dilu ki^n
Tieu chuin 1.12(0) 1.33(0) 2.18 (0) 2,26 (0) 2,31 (0) 2,49 (0) 1.33(0) 2,40 (0) 1,49(0)
Ngim nude 0,92 (18) 1,08(19) 1,12(49) 1,23(46) 1.27(45) 1,32(47) 1,08(19) 1,23(49) 1,19(20)
LSo hoa nhift 0,46 (59) 0,51 (62) 0,53 (76) 0,57 (75) 0,59 (74) 0,76 (69) 0,51 (62) 0.74 (69) 0.56 (65)
Nhift 4m 0.46 (59) 0.50 (62) 0,50 (77) 0,51 (77) 0,53 (77) 0,60 (76) 0,50 (62) 0,57 (76) 0.52 (65)
Nghien edu i n h hudng eua ham lupng phy gia giu nude d i n cydng dp bam dinh trong eae dilu kien thi nghiem dupe khio sat vdi cae d p phii V2, V9, VI0. Kit q u i (bing 6) cho thly khi tang ham luong phy gia P2, cydng db bam dinh eua vda dan tang 1,9 lln trong dilu kien tieu chuin. Tuy nhien, trong dilu kien ngam nude, lao hPa nhiet va sau 20 chu ky nhiet Im, cudng db bam dinh suy giim mgnh. Trong phgm vi nghien edu, dilu kibn dp I m cao it nguy hgi hon dilu kien nhiet dd cao. D i l u kiln nhiet I m i n h hudng Idn nhit d i n cudng dp b i m dinh cua vda dan.
Kit q u i thi nghiem cudng d$ bam dinh eua d c d p phii V I , V2, V11 (bing 6) cho thly cydng dO bbm dinh d t i t d c i c dilu kiln thi nghiem d l u chju inh hudng eua lupng dung xi mang. Lypng diing xi mang tang thi cudng db bam dinh cua vda dan tang mpt each ty le. Mde dp tang cudng d i bam dinh phy T9P chl KHCN XSy dung - s6 4/2012
thupc vao dilu kipn thi nghiem co t h i dgt tren 15%.
Tuy nhien, muc dp suy giam cudng dp bam dinh trong eae dilu kien thi nghiem ngam nude, lao hba nhiet, nhibt I m so vdi dilu kien chuin Igi tang khi tang lupng dung xi mbng. Theo dP, khi tang lupng dung xi mang 10%, mde dp suy giim cudng dp bbm dinh trong dilu kibn ngam nude tang thbm 1%, trong dilu kien lao hba nhiet va nhiet I m thang them 3%.
Tuy nhien, khi tang lupng dung xi mbng gia trj tuybt d i i cudng dp bam dinh trong ebe dilu kien thi nghiem tren v i n tbng nhung d mde dp khbng Idn.
Cb t h i thly ring mde db suy giim cydng dp trong dilu kien nhibt I m khbng nho hon mde dp suy glim cudng d i bbm dinh trong tdng dieu kien ngbm nude va lao hba nhibt. Dieu nay cb t h i giii thich bdi t i c ding ding thdi eua nhibt dp va dO am tdi hb. Do dp, cudng db bam dinh sau 20 chu ky nhiet am la chi
43
VAT LIgU - MOI T R U ^ G • KY T H U A T HA T A N G
tieu dpc Ibp vdi eae chi ceu cydng db bam dinh trong cbc dilu kiln khac. Danh gia anh hudng eua chung logi va lupng dung vbt lieu d l u vbo tdi cudng dp bam dinh sau 20 chu ky nhibt I m cho t h l y d l dam b i o dp b i n ciJa vda d i n trong d i l u kipn Viet Nam, cb t h i su dyng thanh phin vda dan bao g i m 40% xi mbng, 2%
phy gia polyme tao dinh, 0,8% phy gia gid nude.
4. Kit l u | n vb k i l n nghj
D l nang cao chit lupng va dp b i n eiia he i p lat, n h i t la i p lat ngogi thIt d n p h i i d i n h gia anh hudng ciia dilu kien khi hbu Viet Nam tdi he. D i l u kien nay cb t h i dupe mP phong blng cae chu ky nhiet I m .
K i t q u i nghien edu cho t h l y cudng dp b i m dinh sau 20 chu ky nhlpt I m lb mbt ehi tieu dpc lap phin anh dupe i n h hudng tuong h i eua eae y l u t i thdi tilt (nhiet dp, dp I m va sy thay d i i theo chu ky eua cac y l u t i tren) trong d i l u kien Viet Nam tdi he i p lat va cb t h i duoc sd dyng Ibm tibu chl dbnh gia dp b i n cda vda dan trong dilu kibn Viet Nam. Khi db, gia tri cudng dp bam dinh sau 20 chu ky nhiet I m eiia vda dan d n quy djnh Idn hon 0,5 N/mm^.
Nghien edu anh hydng ciJa vbt lieu d l u vao tdi chi tieu cudng dp bam dinh sau 20 chu ky nhiet I m cho thly Chung logi va ham lupng phy gia polyme lb cac y l u t i chinh quyet djnh dp b i n cua vda dan.
Blng cae t i i uu hPa thanh phin vat lieu d l u vao, db chdng minh k h i nang c h l tgo vda dan d i m b i o yeu c l u v l d i b i n trong d i l u kien khi hau V i i t Nam.
TAI U $ U THAM K H A O
1. NGUYEN T I E N B I C H . C6ng tac bS tdng trong d i l u kifn khi hgu ndng I m Viet Nam. NXB Xiy dung, 2004.
2. NOEL P. Mailvaganam Effective Use of Bonding /Vgents.
Construction Technokigy Update No.11, Dec. 1997.
3. OZKAHRAMAN H. T., ISIK E. C. Effect of chemical and mineralogical composition of aggregastes on tensile adhesion strength of tiles. Construction and Building Materials. Vol. 19, no. 4, pp. 251-255. 2005.
4. HEROLD H. ModificatKin of ceramic tile adhesives with redispersible polyme powders. QUALICER 98. V World Congress on Ceramic Tile Quality. General Conferences and Communications II; Castellon; 8-11 Mar. 1998. pp. I1191-200. 1998.
5. JENNI A., HOLZER L.. ZURBRIGGEN R.. HERWEGH M. Influence of polymer on microstructure and adhesive strength of cementitious tile adhesive mortars. Cement and Concrete Research. Vol. 35, no. 1, pp. 35-50. 2005.
6. HryeH TMeH RIAK Oco6eHHOCTM TaepAeHM!) 6eT0Ha B ycnoBMnx )KapKO-Bna)KHoro xnMMaTa /npnueHMTenbHO K ycnoBMXM BbeTHawa./Jucc... K.m.H., -M., 1981.
7. 0au BaH XoaH BeroHbi 6e33au(MTHoro cnon QespynoHHbix Kpoeenb. SKcnnyaTMpyeMbix B ycnoBunx BnawHoro )KapKoro KntiMara BbeTHaua. fiucc... K.m.H., -M., 1993.
8. XoaHr MuHb /]biK MenKosepHMcrbiii SeroH ppn MenKOurryMHbix AopoMwbix v\3p,er\m, SKcnnyarvipyeMbix B ycnoBMRX BnaiKHoro xapKoro Knuuara BbeiHaMa.
/]ucc.... K.m.H., -M., 1998.
Ngay nhin bai: 18/12/2012.
44 T^p chi KHCN XSy dung - s6 4/2012
