KHOA HOC CONG NGHE
S U DUIMG PHAIM IVIEM L I F E - 3 E 5 T R Q M G T H I E T K E CAC COIVG TRilMH B E T O M G COT T H E P T H E O D O BEIV
Tril van Quta'. Nguyen Long KhJnh' T6MTAT
Bai bao gioi thieu mo hinh Ufe-365 ho tra trong viec thiet ke cac cong trinh be long cot thep theo do bt'n.
Tliong s6 dau vao can thiet cho mo hmh nhir he so khuech lan. nong do clo tich luy tai be inji be long, nhiet do... Mo hinh Life-36.5 da du doan hofp K duoc thoi gian khoi dau an nion tj ctia be long sir dung hai loai XI mang khac nhau: xi mang PooclSng ben sunphat va xi mang PooclSng thong thirong; be tong lam viec trong hai moi tnrcmg khac nhau la vung ngap nuoc va ^ n g khong khi. Kel qua cho thAy ket cau be tong fiij dung xi mang Pooclang thong thuong bi an mon soni hon rat nhieu so vcn kel ciiu be tong sii dung XI mang PooclSng ben sun phaL
TIT kh6a: Be long cdt thep. khoi dau Sn mdn, xi mang Pooclang. .vi mang ben sunphat. Life-365.
1 . MO BAU
Ddi voi cong hinh de bien co sii dung ket cau be long cdt thep lam tuong chdn phia bien, dua theo TCVN 9901-2013 |1], ket cau be long cot thep tiep xuc vcn moi truong nuac bien do vay phan kel cau nay bi an mon rat manh. An mon be long cot thep la nguyen nhan chii yeu gay hu hai va xuong cap ciia cac cong trinh be tong cdt thep hong qua trinh lam viec. Tuy nhien. trong lieu chudn TCVN 9901-2013 [1] cung nhu heu chuan TCVN 9346-2012 [2] chua CO thiet ke tinh loan theo do b^n ciia k^t cau be tong trong moi ti-uong nuoc bien. lliay vao do. lieu chuan TCVN 9346-2012 [2] yeu cdu sir dung be long b^n sun phal (PCSR) va cac phu gia khoang nhu ho bay (FA), muoi silic (SF) dcii voi be long lam viec trong moi tiTjong nuoc bien. Di&u nay chua tao thuan lpi cho viec dmh Iuong hay lua chon vat heu sit dung cho cong trinh be long cdt thep trong moi tixrong nuoc bien. Do vay, viec danh gia thoi gian khoi dau an mon ti la thoi gian cdn thidt de mpt Iuong dii do (hay con goi la n6ng do toi han) tham nhap qua b^
day lop be long bao ve va tich tu dii hen bd mat cot thep tir do khoi dau qua tiinh an mon theo dinh nghia hioi tho sir dung ciia ket cau be tong c6t thep Tutti [3], xac dinh la can thiet de co thd giiip viec lua chon loai xi mang sir dung, cung nhu phu gia khoang.
Life-365 [4] la phan mem quan trong cua cac ky su thiet kd lai Hoa Ky trong viec thidt ke cong trinh be tong cot thep theo do bdn. Do vay, bai bao nay se lap tiling vao gioi thieu phan mem Life-365, cung nhu cac phuong trmh chinh dupc sir dung trong phdn mem va cac thong s6 ddu vao cua mo hinh
nh^in ap dung thuc td cho didu kien cong trinh be long cdt thep a Viet Nam.
2. dOI THEU PHAN IVBVILH-365 2.1. Phuong trinh lan truydn ion clo
Vbi bai loan Ihiet kd tudi tho cong hinh theo do bdn, Life-365 Ian lupt phan tich qua 4 budc sau:
BucTC 1: Du bao thdi gian khdi dau an mon cdt thep hong be tdng.
Budc 2: Du bao thdi gian lan truydn an mdn - khi an mdn dat tdi mdt gia hi nhal dinh. Thdi gian cho Ian sua chira ddu lien la; l.|.=t, -M^.
Budc 3: Xac dinh Iich sira chua sau Ian sua chua dau tien.
Budc 4: Danh gia chi phi vdng ddi sir dung cdng hinh dua tren cac gia In thidt kd ban dau. (cac bien phap bao ve an mdn) va chi phi sua chti'a hong luong lai.
Tuy nhien, do gidi han vd khudn khd cua bai bao, nen chi cd the dien giai thdi gian khoi dau an mdn I5 duoc du doan bdng md hinh Life-365. Do dd cac phuong trinh hmh bay dudi day la dimg de tinh tl-
Du bao giai doan khdi dau an mdn ti se dua hen su khudch tan ciia ion clo. Do chenh lech ndng do, cac ion d o tir be mat ciia ket cdu be tdng se khuech tan vao hong be tdng tdi cdt thep. Giai doan nay kel thuc khi nong dp ion d o tai be mat cot thep dat ddn nguong ndng dp tdi han gay an mon. Tu dmh luat thii hai cua Fick [5] ap dung cho khuech tan mdi chieu:
dt dN"
Trong dd: C - ham lupng do, D - he so khudch tan, X - chidu sau tir bd mat be tong, t - thoi gian.
= D , — ^ (1)
Dai lioc Ccing nghe Gia Email: quanlv@uU cdu.^
thc-jng van tai
=uiLD UA PUAT TPICN N O N G THON - KY I + 2 - THANG 2/2020 55
KHOA HOC CON^ »-.^.^
D it)=D,
Phdn mdm Life-365 su dung dinh luat thu hai ciia Fick voi he so khudch tan bidu kien D3(t) phu thupc vao thoi gian. Trong Life-365 he so khudch tan thay ddi theo thoi gian duoc bieu dien bang quan he sau:
t,_. ."
• ~ - (2) Trong dd: Da(t): he sd khuech tan tai thdi gian I;
D^,^: he so khudch tan tai tudi 28 ngay. m: he so suy ydu ciia khuech tan, la mot hdng so: t^,: thai gian tieu chuan.
Phdn mem Life-365 lira chon cac gia tn va m dua tren chi tiet thanh phdn cdp phdi cua be tdng sir dung (ty le nuoc/xi mang: N/X. loai xi mang cimg vdi ham Iuong phu gia khoang) hoac cac gia tri nay dupc nhap true tiep thong qua cac phep do hien trudng va trong phdng thi nghiem. Khi thdi gian t cang Icm he so khuech tan tidn tdi gia tn vo ciing nhd so vdi he sd khudch tan co sd. tuy nhien dieu nay khdng chinh xac. Nhdm tranh dieu nay phuong trinh (2) chi diing vdi mpi nam, tir 25 nam h d di gia tn he sd Dj(t) = D^(25 nam). He sd khudch tan d o la tham sd vat heu, he sd nay giir vai hd cdt yeu hong du bao tudi tho cua kdt cau be tdng phoi nhiem d o cua mdi trudng bien. Vdi cac cong Q-mh vira xay dung cd the lam thi nghiem dd xac dinh gia tri dac tnmg cua he so khudch tan D,,^s- Nhieu nghien cuu cho thay, ndng dp clorua tdi han tang khi ty le N/X giam [6, 7]. Hon nua, ty Ie N/X va bac hydrat hda anh hudng tdi do rdng cua hd xi mang, do vay anh hudng tdi ham luong oxy sdn cd va ham lupng nude hong be long.
Nam 1997, Stamsh va nnk [8] da phat ti-idn mdi quan he giiia D^ j^va ty Ie N/X cho be tdng da chuan hoa a nhiet dp 20"C dua hen mdt co sd du heu Idn cac thi nghiem khudch tan ddi vdi be tong xi mang Pooclang thong tliudng, da dua ra quan he thuc nghiem dd hnh cho be tdng xi mang Pooclang thdng thudng nhu phuong trinh 3.
D , , , = lxlO^-'^''^*^^^"''^ (3) He sd khuech tan phu thude vao nhiet dp dupc bieu didn bang phuong trinh:
' r . 1 1 • D , T = D , ; = e x p - , ~ - y : (4)
D^CO: he sd kliudch tan bidu kidn tai thdi gian t va nhiet dp T
D,_,,.: he sd khudch tan tai thdi gian 28 ngay va nhiet dd tieu chudn.
U: nang lupng kich hoat khudch tan l^^Of^
J/mol).
R; hdng sd khi ly hidng: T: nhiet do hiyet doi.
Trong md hinh,T„, =293 K (20 C). nhiet do T cua be tdng tliay ddi theo thdi gian tiiy thuoc vao vi tn dia ly hoac dupc chpn bdi ngudi su dung. '^<^''^' vimg dia Iy khdng dupc dinh nghia trong co so du heu cua Ufe-365, gia ti-i nhiet dp se duoc nhap bdi ngudi su dung dira hen cac ca sd dir heu co san da dugc xudt ban.
Dieu kien hep xuc moi ti-udng d o cua cdng tnnh be tdng cdt tliep (vi du: tdc do dat den ndng do Clo tich liiy Idn nhat tai bd mat cdng trinh) diroc dinh nghia bdi md hinh dua tren ba each tidp can:
+ Life-365 cung cap mdt co sd dir heu dua tren loai hinh kdt cdu cdng trinh (vi du: ban mat can, bai dd xe). kidu tidp xiic voi mdi tnrdng (nuoc bidn hoac mudi hda tan) vavi tri dia ly (Chicago, New York...).
+ Ngudi sir dung cd thd hire tidp dinh nghia cac tham so nay.
+ Ngudi su dung cd the tinh ndng do lon nhat dua tren thi nghiem xac dinh ndng dp Clo tlieo tieu chuan ASTM C1556 (cac tham sd dupc suy ra tir cac gia tri ndng dp tai thai diem do).
Giai phuong trinh sai phan huu han (1) vdi gia tri D^ dupc tinh tai moi budc thdi gian sii dung phuong trinh (2) va (3) cho nghiem la thdi gian khdi dau an mdn t;.
2.2. Cdc thdng s6 ddu vdo cdn thidt dd tinh thdi gian khoi ddu Sn mdn t, bdng phdn mdm Life-365
Cac thdng sd dp ben can cho viec tmh thdi gian khdi ddu an mdn ndu phan mdm Life-365 cia c6 sdn CO sd dir heu ddia:
Vi tri dia ly.
Loai hinh kdt cau cdng tnnh va loai moi trudng tiep xiic.
Chieu day Itrp bao ve cot thep .
Chi tidl hda cac bien phap chong an mon su dung: ty le N/C, ham lugng cac phu gia va chal lic chd an mdn, kidu cdt thep sir dung va loai son bao ve kidu va tinh chat cua Idp chdng tham neu co.
Dua hen cac thdng tin hen, mo hmh se lua chon cac he sd de tinh tiioi gian khdi dau an mon. Tuy nhien ndu cac thdng tin hen khdng day dii Ihi cac diong so do ben cdn phai nhap la:
Nong dp clo tich liiy ldn nhat lai be mat be lonp Ndng dp d o ldi han tai be mat cdt thep C
56 NONG NGHIEP VA PHAT- I ».i.^M/:i T U O M .
KY1+2-THANG 5/2020
KHOA HOC CONG NGHE
Thdi gian cong trinh tidp xiic vdi moi tnrdng clo dd cd duac ndng dp d o tich luy lon nhat tai bd mat t^,
He sd khudch tan bieu kien D ^ m he sd tinh den anh hudng thdi gian den su thay doi he so khudch tan bieu kidn.
Nhiet dd hang thang.
Dieu kien tidp xhc vdi moi tnrdng do.
Cap phdi: ty le nudc/xi mang. ham lupng phu gia (mudi sihc, tro bay. xl Id cao, chat gay uc che an mdn).
Hinh dang kdt cdu: ID, 2D (chii nhat, hdn), chidu day Idp be tdng bao ve Xj
Tren day la cac thdng s6 dp bdn cdn thiel cho du doan thdi gian khdi dau an mdn ciia cong trinh be tdng cdt thep, sd lupng cac tham sd cd thd dupc Idy lu ddng hong co sd dir heu ciia Life-365 hong trudng hpp cd cac thdng tin day dii. ciing cd the dinh nghia bdi ngudi su dting hoac kdt hpp ca hai bien phap ndu cac thdng tin khdng day dii hoac khdng dang tin cay.
Cung cd the gpi cac thdng sd do ben hen la cac thdng sd do bdn cua mot cdng trinh be tdng. Trong phan tidp theo. phan mdm Life-365 se dupc ung dung du doan thdi gian khdi ddu an mdn ciia mdt ket cau be long cdt thep tai viing bien cua bidn Bach Ddng - Quang Ninh.
3. AP DUniB PHAM M ^ l f E - 3 6 5 BE DU ODAN TUOI GIAN KHOIBAUAniMDhlT,
Cac thdng sd dp ben cho Life-365 de tinh Ihdi gian khdi ddu an mdn cho cdng trmh be tdng cdt Ihep
De thuc hien npi dung nay, can thidt tim mot cdng trinh cd su hrong ddng luong ddi vdi cdng trinh be tdng cot thep dupc xay dimg tai ciia bien Bach Ddng, ma cdng hinh dd cd sdn cac thdng sd dp bdn cdn thidt dd tir dd su dung cho cdng trinh be tong cdt thep nhdm du doan tuong doi thdi gian khdi dau an mdn t| ciia cdng trinh.
3.L Kich thude k^t cdu
Da dd xuat sir dung cac thdng sd do bdn dau vao da duoc nghien cihi tai cac cay cdu khu vuc bien Traslovslage (Thuy Didn) [9] do cd su tirong ddng ve cdp phdi nudc/xi mang hong thi cdng, loai xi mang su dung, ndng do man cua nude bidn tai kliu vuc ciia bien Bach Ddng. Theo nghien cihi cua X. Mari va nnk [10], nong dp mudi cao nhat tai cira sdng Bach Ddng duoc cdng bd tir 10-15 g/kg nude bidn. Sd lieu nay cho thay, vimg bidn TrSsIdvsIage (Thuy Dien) cd ham luong mudi hoan loan gidng vdi viing cua bien Bach Ddng (Viet Nam). Thdi gian khdi ddu an mdn cua cong trinh he tdng cdt thep dupc tinh toan hong hai tnrcmg hop: (i) tai vimg bao hda hoan toan ngap nude: (ii) tai vimg khdng khi. Ngodi ra. Ian truyen ion clorua theo mot hudng duy nhdt do vay md hinh ID dupc sir dung vdi chidu day Idp cdt thep bao ve x,i = 5 cm.
3.2. Hdm lugng clo tich luy 16n nhdt trong be tdng C C , ^
Theo cac kdt qua nghien ciru Henrik va nnk (2015) i9], sd lieu vd nong dp d o tich luy trgn bd mat be long duoc do hen nhieu cay cdu khac nhau d vimg bien Traslovslage (Thuy Dien) hong thdi gian dai d cac dp tuoi khac nhau cua cong trinh. Nhu tai cdu Vejie Fjord Bndge, ham lupng d o tich luy hdn bd mat be long duoc do sau 17 va 34 nam. Theo dd, gia tri Cs max khoang 0,6% khdi lupng be long. Cac mau thii deu dupc do d cac dp sau khac nhau trong khoang 10 mm dau tren be mat be tdng tai nhimg khu vuc ma be tdng chiu tac dpng cua mdi trudng khac nhau la mdi trudng ngap nude va mdi trudng khong khi.
Cac sd heu dupc thuc hien hen nhieu loai be tdng khac nhau, tiong khudn khd ciia bai bao chi khai thac sd leu ddi vdi 02 loai xi mang la xi mang Pooclang thdng thudng (duong mau xanh dam) va xi mang Pooclang bensunfete (dudng man tim).^]ieucu.iheTivj\un\\\.
(b) (a)
Hinh 1. Bi^u &6 phu thu6c ham lining Clo tich luy theo th6i gian trong khu vuc; (a). ngSp nu6c v^ (b). khu vuc khong khi biin [9]
. „ c o „ A Du.TTnicMMAMgTHON-KY 1 + 2 - THANG 2/2020 57
KHOA HOC COtiSf .^«?.- Tir bleu do tren. thu duoc so lieu cu the nhu sau;
Bang 1. Ham Immg clo tich lu? Irtn b^ mat cong trinh C. (% khdi lupng bt t6ng) l,
2S (ngay) 10 (nam) 20 (nam)
Doi voi be tong sir dung XI mang Pooclang ben sunfale
Viing ngap nuoc 0.43 0.86 1.12
Vung khong khi 0.24 0.3 0,5S
Doi vcn be long su dung xi mang PoocIAng thong thuong - Viing ngap nuoc
0.36 0.62 0,61
Vung khongJillL- 0.24
o.;i (l,5li 3.3. H§ so khudch tan bidu kidn
He sd khuech tan D., dupc tinh tu ddng theo phuong trinh (3), ap dung vdi trudng hpp cdng trinh be tdng cdt thep, theo thidt kd thanh phan be tong, t\""
Ie N/X su dung la 37,5% ddi vdi be tdng xi mang Pooclang thdng thudng:
D.,,,= 1 X 10 (•i2.'«*^->'^"375) ^ g^9i J. 10-'^ (mVs).
Ddi vdi be tdng sir dung xi mang bdn sunphat, da sir dung gia tri do thirc nghiem cua Henrik va nnk (2015) [ 9 1 . D , . s - 0 . 5 5 x l 0 ' - ( m - / s ) .
3.4. Nhi^t do khu vuc bidn Bach D ^ Nhiet do phai khai bao hong khi tinh loan su dung phan mem life-365 dupc su dung dir lieu nhiet dd ti'ong nam tai khu vuc Ha Long - Quang Ninh, gdn noi cdng trinh be tdng cdt thep xay dung. Theo dhlieu cua nhiet dd nude bien loan cau [11], nhiet dp ciia viing bien Bach Ddng duoc bidu didn trong hinh 2:
Hinh 2. Bi^u dO nhi^t dO fa-ong nam khu vyc B^ch Ddng - Quang Ninh
3.5. Tinh todn thdi gicui khdi ddu an mdn ti ciia cong trinh
Thong sd ddu vao de tinh loan Ihdi gian khdi ddu an mdn tj cita cdng trinh be tdng cdt thep dupc md la hong bang 2:
Bang 2. Tlidng sd ddu vao dd tinh todn thdi gian khdi ddu an mdn ti v^ kdt qua thdi gian khdi dau im mdn dupc du doan boi md hinh Life-365
Hang muc d- Chieu day lop bao ve be long (cm) C^; - Ham luong Clo tich
luy lon nhat trong 10 nam D- He so khuech tan Clo sau 28 ngay (m-'/s)
XM ben sunphat XM Pooclang XM hgn sunphat
XM Pooclang m- he so dieu chinh nhiet do Thoi gian hvdi'at hoa hoan toan (nam) C, - Nong do Clo toi han (% klioi luong be tong)
Vimg ngap nu6c 5 0,86 0,62 0,55 X 10'^
6,91x10'^
0,26 25 0,05
Vimg khong khi 5 0,3 0,3 0,55 X 10 "
6,91 X l O "
0,26 25 0,05 Sau khi cd dii dii lieu, ta tinh dupc thdi gian khdi
ddu an mdn ddi vdi timg trudng hpp nhu sau:
a. Ddi vdi vung ngap nude va be tong ben sunphat
Budc 1: Nhap kich thuoc kdt cau. Chidu day lop be tdng bao ve (d): 50 mm.
Budc 2: Nhap thdng sd vd nhiet dd tiimg bmh cac thang hong khu \Trc xay dung va ham luong d o
tich luy Ion nhdt. Ham lupng clo tich luy tren be mat sau 10 nam: 0,86% khdi lugng be long.
Budc 3. Nhap sd heu lien quan den I) ,/ m C "
tinh toan.
+ He sd khudch tan d o bid ngay): 6,91 x 10'^ (mVs).
+ He sd phu thupc nhiet do m: 0,26 [12]
bieu kien: I)^,^ (28
NONG NGHIEP VA PHA^ '^'''^' '^ry^^r^ jHOt^ - KY 1 + 2 - THANQ 2/2020
KHOA HOC CONG NGHE
+ Ham lupng d o toi han: 0.05% khdi lupng be tdng [13).
Cdc budc tinh todn nay duc«c gidi thieu trong hinh 3:
a) nhap kich Ihudc cdng trinh
b) Nhap cac Ihdng sd nhuH do va ham lupng cho hch luy
c) Kdt qua tinh
Hinh 3. Ba birdc tinh toan fhdi gian khdi ddu an mdn tl cho vimg ngap nude
Cac budc tinh loan duoc lap Iai tuong tu cho viing khdng khi va be tdng Pooclang thdng thudng.
Md hinh Life-365 cho du bao Ihdi gian khdi dau an
mdn ciia hai vung va hai loai xi mang la khac nhau, kdt qua dupc tdng ket hong bang 3.
Bang 3. Thdi gian khdi ddu an mdn ti (nam) dugt dtr doan boi md hinh Life-365 Loai xi mang sir dung
Xl mang Pooclang bdn sunphat
Xi mang Pooclang thdng thudng
Vimg ngap nuoc 69 13
Vimg khdng
khi 136 15 Cd the nhan thay rdng be tdng sir dung xi mang Pooclang bdn sunphat cd thdi gian khdi ddu an mdn cao hon rat nhidu ddi vdi be tdng Pooclang thdng thudng trong ca hai viing: viing ngap nude va vimg khdng khi. Viing ngap nude cd thdi gian khdi ddu an mdn soni hon do cd ndng dp tich luy clorua tai bd mat cao do luon tidp xiic vdi ion clonia trong nude bien. Cd thd thdy rdng mo hinh Life-365 da giiip viec dinh lupng thdi gian khdi ddu an mdn ciia cdng hinh be tdng cdt thep hong mdi trudng ion clorua.
4. KET LUAN
Thdng qua phdn mdm Life-365, da du doan dupc tudi khdi ddu an mdn ciia cdng trinh be tdng cdt thep sir dung hai loai xi mang khac nhau: xi mang Pooclang bdn sunphat va xi mang Pooclang thdng thudng trong hai vimg khac nhau: vimg ngap nude va vung khdng khi. Ket qua cho thay xi mang bdn sunphat cd kha nang chdng an mdn cao hon xi mang Pooclang thdng thudng, didu nay phii hpp vdi khuydn cao ciia TCVN9346-12. Viing ngap nude bi an mdn sdm hon vung khong khi.
Viec thidt kd theo dd bdn cua cong trinh be Idng cdt thep giiip du doan dupc tudi tho cung nhu thdi gian sira chira cua cdng trinh be tong cdt thep. Viec thidt ke nay cd Ihe sir dung ddn su hd h a ciia phdn mem Life-365. Viec tinh loan thdi gian lan truydn an mdn tf tu dd xac dinh duoc tudi thp cua cdng hinh can dupc tien hanh hong cac nghien cuu sau.
Ldi CAM ONI
Nghien cuu nay duoc tdi tig- bdi Quy Phal trien Khoa hoc va Cong nghe Qudc gia (NAFOSTED) tiong d4 tai ma sd 107.99-2018.3.37.
TAl UEU THAM KHAO
1. TCVN9901-13. Cong trinh thuy loi yeu cdu thietkede bien. 2013.
MnMCi MGHlEP V A PHAT TRIEN N O N G THON - KY 1 + 2 - THANG 2/2020 59
2. TC\'N'9346-12. AW cau be tong, be tdng cot thep • Veu cau bao ve chong an mon tiong moi tiirdng bien. 2012.
3. K. Tuuth. 1982 Corrosion of steel in concrete. Swedish Cement and Concrete Research Institute, Stockholm.
4. M D. A. Thomas and E. C. Bentz, 2OO0. Life- 365 computer program for predicting the service life and hfe-cyde costs of reinforced concrete exposed to chlondes. Am. Conor Institute, Comm., voL 365, pp.
1-87.
5. D. H. Pham. T. T. Tran, K. C. Thai, V. D.
Dao, and T S. Nguyen, 2016. Thiet kd kel cau theo do ben, Nha xudt ban Giao thong Van tai.
6. K. Pettersson, 1994. Chloride threshold value and the corrosion rate in reinforced concrete. Proc.
Nord. Semm., pp. 257-266.
7. 0 . Poupard, A. Ai •t-Mokhtar, and P.
Dumargue, 2004. Corrosion by chlorides in reinforced concrete: Determination of chloride
concenhation threshold by impedance sixiiroSLOPJ- Ceni. Conor. Res., vol. 34, no. 6, pp. 991-U*'^-
8. K. D. Stanish. R D. Hooton. antt M ^•
Thomas, 1997. Teshng tiie Chloride Penetration Resistance of Concrete%: A Literature Review.
Predict Chloride Penetration Conor, p. 31 9. B, Henrik and E. Serensen. 2015. Now model for chlonde penetration into concrete*? Investigation of marine bridges in 2012.
10. Xavier Mari, Jean-Pascal Torreton, Claire Bich-Thuy Tnnh, Thierry Bouvier. Chu Vaii Thuoc, Jean-Pierre Lefebvre, Sylvain Ouillon (2012).
Aggregation dynamics along a salinity gradient in the Bach Dang estuary, North Vietnam.pdf.
ll.http://www.seatemperatnre.org/asia/viebia m/ha-long.htm.
12. P. B. Bamforth, 1999. ITie denvation of input data for modelling chloride ingress from eight-year UK coaslal exposure trials. Mag. Conor Res., vol, 51, no. 2, pp. 87-96.
13. Infociments. 2005. La noinie belon NF EN 206-1.
USING LIFE-365 SOFTWARE IN THE DURABXLTrY DESIGN OF REINFORCED CONCRETE CONSTRUCTION
Tran Van Quan, Nguyen Long Khanh .Summary
The article inti'oduces the Life-365 software which assists in the durability design of reinforced concrete construcdon. Input parameters required for the software such as, diffusion coefficient, chlorine concentraUon accumulated at concrete surface, temperature... Life-365 model has reasonably predicted the initial Ume of steel corrosion in the reinforced concrete using two different types of cement' Portland cement and Sulfate Resistance Portland Cement (SRPC): Reinforced concrete exposures to two different envu'onnienls, submerged zone and air. The results showed Ihat the concrete slmcture using Portland cement usually corroded much earlier than the concrete structure using SRPC.
Keywords: Reinforced concrete. Initial time of steel corrosion, Pordand cement, Sulfate-resistanl Portland cement. Life-365 sok^vare.
Ngudi phan bidn: PGS.TS. Nguyfin Quang Phii Ngay nhan bai: 9/12/2019
Ngay thong qua phan bien: 9/01/2020 Ngay duydt dang: 16/01/2020
60 NONG NGHIEP VA PHA^ TDIFN NONG THON - KY 1 + 2 - THANG 2/2020