KHOA HOC CONG NGHE
MO PHOIVG LAIV TRUYEIM lOIXl CLO TROIMG lUOl TRUOIVG KHOIVG BAO HOA VOI BAI TOAIXI HAI CHIEU
Tran Van QuanS Nguydn Quang Hung^
T6MTAT
An mon clo voi ket cau be long cdt thep la nguyen nhan bang ddu gay ra pba hoai va xudng clip cong trinh, dac biet ddi vdi cac cong trinh be tong cdt thep trong mdi tmdng bien va khong bao hda hoan toan trong mrdc. Do vay, nghifen ciiu tap tmng vao phat tnen md hinh bai chieu tmyen km kdt hop truyen cblit de xac dinh cac mien ndng dp ion clo trong mfii trucmg be tong xi mang Portland khong bao boa hoan toan. Ket qua cua mo hinh cho thay, trong moi trudng khong bao hoa hoan toan, qua trinh truyen am va lan truydn ion clo diSn ra manh me hon, tir do gay ra nguy ca an mon cao hon. Mo hinh thanh cong Irong viSc xay dung cac mien do bao boa va mien nong do ion clo trong be tong. Cac mien nay la cac midn cong ddi vol truong hop be tong mpt phan ngap trong nirdc va mot phan trong khong khi. Cac mien phan bd binb chu nhat, thay doi theo chieu sau nhu bai toan mot chieu ddi voi ngap trong nuoc hoac trong khong khi hoan toan.
Tir khda: Truyen am. lan truyen ion clo, be tong xi mang Portiand. an mon cdt thep. mo phong.
1 . MO DAU
An mon be tdng, cdt thep la nhiing nguyen nhan chu yeu gay ra hu hai, pha huy do bdn cac cdng trinh be tdng cdt thep. Dac biet, cae cdng trinh be tdng cdt Ihep nhu ke bien, de bien, cac cdng trinh bd tdng cdt thep phue vu an ninh quoc phdng duoe xay dung trong mdi trudng cd tinh an mdn cao nhu nude bien vdi ndng do mudi NaCl cao. Cac ion clo la nguyen nhan gay ra khoi ddu cho an mdn cdt thep trong be tdng, cung nhu hinh thanh cac khoang ri skt nhu Fe(OH):,, Fe4(0H)sCl.... cac khoang nay cd tire tich ldn din den mil va pha huy vi cau tnic be tong, tu dd cang tao didu kien cho su xam nhap cua nud-c bien co tinh an mdn cao vao ket eau cua edng tiinh gay xudng cap tram trong dp ben cdng trinh [1]. Do do viec du doan ludi thp, thdi diem hu hai, mue dp hu hai cho cdng trinh be tdng cdt thep la hdt sue can thidt nham tidn hanh bao ti-i, duy tu dam bao chat luong khai thac cho cdng trinh be long cdt thep.
Hien nay, viec dung cac md hinh sd du doan ca che suy giam tiioi thg, dp bdn eua cac cdng tiinh be tdng col tiiep gay ra boi ion clo dang duac tidn hanh rdng rai tren the gioi [2]. Do chinh xac ciia md hinh quydt dinh den chi phi duy tu, cung nhu kha nang khai thac cdng trinh.
' Truong Dai hoc Cong nghe Giao thong van tai - Tnrong Dai hoc Thiiy loi
Email. [email protected] vn
Hien nay cac md hinh tinh toan thdi gian khoi ddu an mdn cung nhu viec suy giam do bdn cua be tong thudng duoc gia thiet Irong mdi trudng bao hda hoan loan (do bao hda hkng mpt va khdng thay ddi theo thdi gian) nhu life 365 cua Hoa Ky [3], Clmcon [4]. Tuy nhien vung thudng bi xudng cap va suy giam dd ben manh nhat lai la viing be tdng cd dp bao hda thay ddi [5]. Vi vdi be tong khdng bao hda hoan loan, ion clo dupe van chuyen vao sau trong he tdng ddng thdi bang hai ea che la ddi luu (truyen am) va khuech tan (truydn chat), so vdi duy nhat bang co chd khuech tan trong truong hop bao hda hoan toan.
Do vay, da cd mot vai nghien ctm phat trien md hinh sd du doan lan truydn ion clo Irong mdi trudng khdng bao hda hoan toan [61-[9l bang viec md phdng ddng thdi ca hai ca che. Ben canh do, da ed cae md hinh sd nay md phong Ian truyen ion clo trong bai loan mdt chieu do dd chua md ta dugc chinh xac qua trinh lan truyen ion clo cua mdt ket cau be ong vira ngap nude vua trong khdng khi (Hinh 2). Md hinh mdt chieu khd cd the xet tdi anh hudng cua phin ngap nude ddn su truydn am trong be ong ddi vdi phan Irong khdng khi. CQng nhu anh hudng ciia viing khdng khi ddn qua trinh lan truyen ion clo Irong be tdng.
Do do, de nghien ciiu su lan truyen ion clo ti-ong mdi trudng be tdng khdng bao hda ed xet den ddng thdi phan ngap nuoc va phdn ti'ong khong khi, se nghien cuu phat tnen md hinh tioiyen chat ion d o
KHOA HOC CONG NGHE
t r o n g m d i t r u d n g b e l o n g k h o n g b a o h d a h o a n t o a n k d t h p p vdi m d h i n h t r u y e n a m da d u p e k i e m c h u n g t i n h e h i n h x a c t r o n g c d n g b d t r u o c dd ciia n h d m t a c g i a T r d n va n n k [10] (Hinh 1). T r o n g n g h i e n e u u n a y , m d h i n h k e t h p p t r u y e n a m va t r u y d n c h a t d u o c x a y d u n g c h o bai t o a n hai c h i d u s e d u p e t r i n h b a y t r o n g p h a n c a sd' ly thuydt. T h e o s a u d o la h i n h h o e m d h i n h , dieu k i e n b i e n , didu k i e n b a n d a u va c a c t h a m sd can thidt c h o m d h i n h s e d u o c m d ta. C a c k e t q u a va t h a o luan s e d u o c t r i n h b a y tii d o n i t r a k e t luan va k i e n n g h i .
H i n h 1. K ^ t q u ^ m d h i n h t r u y d n im d u g c k i ^ m n g h i d m k h i s o sknh k d t q u a thi n g h i d m b a y h o i ciia
b e t d n g x i m a n g P o r t l a n d [10]
2. CD Sff LY THUYET MQ PHONG TRUYBV AM VA TRUYEN CHAT BAI TOAN HA] CHEU
2.1. M d h i n h t r u y d n §jxi vk t r u y d n c h a t P h u a n g t r i n h lien t u c c h o moi t r u d n g chat long c d t h e d u p e vidl dudi d a n g 111]:
^ = v « , + p , a (1)
Trong dd, V la loan tu nabla; q la luu luong the tich (liay cdn gpi luu lupng Darcy) cua mroc (m^
nude X m'^ mdi trudng x s 0; f la do rdng moi trudng;
PI la khdi lupng rieng cua nude (kg x m ' nude); Q^
ngudn cap nude (m-^ nude x m'-' mdi tiTidng x s'): t la thdi gian (s). Luu luong the lich hay Darcy dupe dinh nghia la ham sd cua gradient ap suat cua nude:
q^Ov= - - ^ ( V / > - / 7 , , y ( ' J (2) Trong dd. Kla van tdc ti-ong Id rdng (mxs'): z la chieu sau (m); V P ta gradient ap sudt ciia nuoc
(kgxm 'xs-^; g la gia tdc ti-png truang (mxs 1; Ku. '^
he sd tham trong moi ti-uong be long bao hda hoan loan (m^; e^ la vec ta dan vi theo phuang tiidng dung va / / d o nhdt (kgxm'^xs^). Ngoai ra, he sd tiidm trong mdi trudng bao hda hoan toan lien he vdi do ddn tiiuy lire K (mxsO thdng qua phuong trinh:
- ^
Vdi h la chidu eao cdt nude dupe bieu didn dudi dang phuang trinh:
P
h = z + (4) P,g
Bieu didn bang chieu cao cdt nude va dp ddn thuy luc, dinh luat Darcy dupe bieu didn dudi dang:
q= ~KWh (5) Trong mdi trudng dp bao hda thay ddi, vdi gia thiet la he sd tham cua qua trinh bay hoi do say khd va qua tiinh tham nude la nhu nhau, ddng thdi khdng ke den qua trinh van chuydn pha khi, phuong trinh Richard la phuong trinh md' rdng cua Darcy, ap dung eho mdi trudng dp bao hda thay ddi theo tiidi gian:
S , 5 , ~ + ^ ^ = V[KKVh\ + Q^, (6) ' dt dt
Trong do, S,.he sd bao hda cua be tdng; S.^ he sd luu trir; k^ he sd tham phu Ihudc vao dp bao hda cua be tdng, tiieo quan he eua Van Genuchten [12]:
S' 1 - 1 - 5 , (7)
Dong thdi theo Van Genuchten, dd bao hda ciia be tdng phu thudc vao ap sudt mao ddn p,. (Pa) tiieo phuong trinh:
•s,= i + ( « | p . | ) " (8) Trong do; n, m. 1 va a la cac tham so thuy luc xac dinh tti thuc nghiem, vai n va m duoc bieu diin qua phuong trinh 9.
(9) M^ suat mao ddn trong mdi truang be tn 'c vao do am ciia moi trimmc? th^-.
thuoc vao do am Kelvin-Uililace
moi truong theo ^ ^ ; „ ^ ^ ^
78 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG
KHOA HOC CONG NGHE
Pc = PI ^ K M„
(10) Trong do, h^ dp am mdi trudng; R hang sd khi ly tudng 8.3147 QxK'xmolO; M^khdi lupng moi nude 0,018 (kgxmol-');T nhiet dp (K).
Tir phuang trinh (4), phuong trinh Richard duoe bieu didn dudi dang:
Bl V -p,^{VP-p,ge:)\ + p,Q^ (11) Trong mdi trudng be tdng cd dp bao hda thay ddi, truydn chat theo hai ca che la ddi luu va khuech tan. Thdng qua dinh luat Fick, mat dd ddng truyen chat theo ca che khuech tan trong mdi trudng be tdng cd the duoc md ta theo phuang trinh:
•/.--OAV(c„)
(12) Trong do, D^la he sd khuech tan hidu qua trong mdi trudng bd tdng; Cc[ nong dp clo trong mdi trudng be tdng (molxVO- Mat dp ddng truydn chat theo ca che ddi luu phu thudc vao luu lupng the tich duoe tinh tir md hinh truyen dm (hd phuong trinh 1-11) dupe md ta theo phuong tiinh sau:
J,=qCa (13) Mat dp ddng tiTiydn chat cua mdt don vi thd tich J la tdng cua hai ca che:
J = J,+J, =-D,Sy{Ca)-^qCa (14) Theo djnh luat bao toan khdi lupng ciia mpt don vi the tich trong khoang tiidi gian t:
^ = - v y (15) dt
VtM M la khdi luang CI trong mdt don vi thd tich bd tdng:
M
Do vay phuang trinh truyen chat ion clo trong mdi trudng be tdng cd the duoc bieu didn dudi dang sau:
^ ^ = D „ V ( S , V C „ ) - V ( , C „ ) (17) Cac phuong trinh (1-11) bieu didn ca che truyen am trong moi trudng be tdng cd dp bao hda thay doi theo thdi gian. Luu luang the tich duoc tinh tir md hinh truydn dm se dupe su dung cho tinh loan trong md hinh truyen chdt (ion clo) trong moi trudng be tdng duoc mp ta trong he phuang trinh (12-17).
2.2. Hinh hpc md hinh, didu kidn bidn, didu kidn ban ddu va cac tham sd cua md hinh
Md hinh be tdng hai chieu vdi kich thudc 1x1, qua trinh trao doi chdt didn ra duy nhat tai mat thoang tiep xiic vdi nude va khdng khi (Hinh 2 va 3).
Hai trudng hgp dupe md phong la trudng hop 1 vira say khd trong mdi trudng do am 50% vira lam udt be tdng trong mdi trudng nude (Hinh 3a); trudng hgp 2 be tdng dugc say khd hoan toan trong mdi trudng dp am 50% (Hinh 3b); trudng hgp 3 bd tdng duoc ngap trong nude hoan toan dd dam bao mdi trudng lam udt 100% (Hinh 3c).
f A
T=:5°C
H
C!
1, Be tong
T=25°C Do SM ban diD:l(ll>%
l m 1
Hinh 2. Qua trinh truydn km (sdy khd vd ldm uot) ciia bd tdng vd xam nh|ip ion clo vao bd tdng
(a) t^-) Hinh 3. Luoi phdn hi cua bd tdng 50 x 50 phan hi (a) Trudng hpp 1: Say khd va ldm udt; (b) Tnrang hpp 2: S^y
khd hodn toan; (c) Ng|p trong nude lam udt hodn toan
KHOA HOC CONG N G H t
Trong ca ba trudng hgp. ludi phdn tu duoc chia thanh 50 x 50 phdn hi. Vdi didu kien bidn va didu kien ban dau ciia md hinb duoc trinh bay Q-ong phdn dudi day.
Be tdng xi mang Portiand duoc sir dung trong md hinh cd cac thdng sd dugc lay luan an cua Mainguy [13], duoe tiinh bay trong bang 1.
Bang 1. Tham sd ciia quan hd thiiy luc Van Genuchten
Bang 2. Dd bao hda S^ cua b * tdng cho didu ki^n bito vd didu kidn ban ddu cua md hinh_—.-^-
Didu kien bien loieu kitMi ban dau
I CI (mol/1) Say kho
0,28 0,546
Lam udt b-ong benmg_
1 1 ^ _ ^
0,546 0
k„,(m2) 3.10-^'
n 1,78
m 0,44
1 0,5
a 5.37X 10-*
^
0,122 Do bao hda S^ duoe sir dung lam didu kien bien va didu kien ban dau cua md hmh truydn am trong hai trudng hop, ndng do CI trong nude bien duoc sii dung cho dieu kidn bien khi be tdng bi lam udt trong trudng hpp 1 va trudng hpp 3 dupe tdng hpp trong bang 2.
3. KET QUA VA THAO LUAN
Md hinh dupe md phdng bdng phdn mem Toughreact (14]. Thdi gian md phdng la 10 nam, cac kdl qua ve md phong truydn am va lan truydn ion clo trong be tdng duoc trinh bay dudi day.
Hinh 4 trinh bay dp bao hda cua be tdng cho trudng hgp mot dupe ngam mdt nira trong nude, mdt mra ngoai khdng khi sau 2 nam, 5 nam, 7 nam vd 10 nam. Cd the nhan xet rdng, vdi dd bao hda Sp ban dau bang mpt, thi dd bao hda ciia be tdng giam ddn theo thdi gian tren toan mien.
0 4 x(m) 0 6
(d) 10 nam
Hinh 4. Truydn dm trong mdi trudng bd tdng xi mang Portland dugc b i ^ didn thdng qua d^ bao h sau a) 2 nam, b) 5 nam, c) 7 nam, d) 10 nam cho hudng hgp 1 ^^ «
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG
KHOA HOC C O N G N G H E
Viing do bao hda hodn toan bdng mdt cd xu hudng co hep lai tai mat ngap trong nude hoan toan theo thdi gian. Nhan thay su thay doi ro rang ve do bao hda cua bd tdng didn ra manh me tai mien trong khdng khi hoan toan. Neu xet theo phuang y chieu cao, cdng xa vimg ngap nude thi mien cd do bao hda thap cang md rdng theo chieu siu. Do vay, dp bao hda khac nhau duge thay ddi theo cac midn cong vi cd su anh huong ldn nhau ciia midn be tdng trong khdng khi va mien be tdng ngap trong nude.
Hinh 5. Truydn dm trong moi trudng bd tdng xi mang Portland dupe bidu didn thdng qua dO bao hda
Se sau 10 nam trong didu Iddn say khd hoan todn trong trudng hpp 2
Khac vdi su phan bo mien bao hda trong trudng hop 1, trong trudng hop 2 be tdng hi say khd hoan toan trong khdng khi, mien bao hda sau 10 nam say khd phan bd la cac mien hinh chtr nhat, thay ddi theo chieu sau khdng cd su thay ddi theo chidu cao khi do bai toan hai chieu trd ve bai toan truyen am mdt chieu. Ngoai ra vide thoat hoi nude trong mien say khd trudng hpp 1 didn ra manh me hon so vdi trong
trudng hop 2. Hien nhien trong trudng hpp say khd trong khong khi, su lan truyen ion clo khong didn ra.
Lan truyen ion clo trong mdi trudng trong trudng hgp 1 dupe the hien trong hinh 6 lan luot sau 2 nam, 5 nam, 7 nam va 10 nam. Cd the nhan thdy anh hudng cua mdi trudng khdng bao hda hoan loan the hien ro qua hinh 6d va hinh 7. Hinh 6d the hien ndng dp ion clo cd trong be tdng sau 10 nam vdi mdt nira ngap trong nude, mdt nita trong khdng khi va hinh 7 md ta ndng dp clo trong mdi trudng bd tdng ngap trong nude vdi he sd bao hda hoan loan bang 1 cho trudng hpp 3. Lan truydn ion clo trong trudng hgp mgt didn ra manh me hon, tham nhap vao be tdng sdu hon trong mien ngap nude so vdi trudng hpp 3, khi ma su thay doi ion clo da vao qua 20 cm, chidu sau.
Cling nhu truydn am, cac mien ndng do ion clo la cac mien cong trong trudng hop mdi do anh hudng cua co chd van chuyen ddi luu dien ra trong mien khdng bao hda hoan toan, khac vdi didn ra mdt CO che duy nhat la khudeh tan trong midn bao hda hoan toan vdi S^ bang 1. Va mien say khd vdn cd su truyen am tir mdi trudng ngap trong nude, do vay vdn ed su Ian truyen ion clo trong midn khdng ngap trong nude.
Viec xac dinh midn ndng dp clo trong bai loan hai chieu la het sue cd y nghia, vdi viec phan bd cdt thep trong vimg be long trong khdng khi, md hinh hai chieu cd the xae dinh duoe ndng dp ion clo tai vi tri timg cot thep, tir dd xac dinh duge nguy co an mdn va tien hdnh eac bien phap duy tu va bao ve cdt thep.
(b) 5 nam
KHOA HOC CONG N G H l
(c) 7 nam (d) 10 nam
Hinh 6. Truydn ion clo trong mdi ti-dng bd tdng xi mang Portland sau a) 2 nkm, b) 5 nam, c) 7 nSm, d) 10 nam long trong khdng khi. Cac vimg do bao hda va viing ndng dp ion clo trong be tdng ngap nude mdt phan la cac mien cong phu thupc chidu sau va chieu sau ngap ciia ket cdu. Do vay vide xac dinh dugc cac midn nay het sue cd y nghia trong viec xac dinh mien cd nguy ca an mdn cao vdi cdt Ihep. Md hinh md phdng vdi dudng ddng nhiet, chua xet den yeu td nhiet dp thay ddi giOra mdi trudng va be tdng, do vay cdn ldm nghien ciiu them trong cac nghien cuu sau nay.
LOI CAM ON
Nghiin cuu nay duac tii tra bdi Quy Phat trien Khoa hoc va Cdng nghi Quoc gia (NAFOSTED) ti-ong de tii ma so 107.99-2018.337.
TAIUEUTHAMKHAO
1. V. Q. Tran (2016). Contiibution a la comprehension des mecanismes de depassivation des annatures d'un beton expose a I'eau de mer theorie et modebsation thermochimique. PhD Thesis. 2016.
2. Projet ANR MODEVIE (2020). PERFDUB.
https://www.perfdub.fr/programme/projet-anr- modevie/ (accessed Apr. 13, 2020).
3. M. D. A. Thomas and E, C. Bentz (2000).
Life-365 computer program for predicting the service life and life-cycle costs of reinforced concrete exposed to chlorides. American Concrete Insti'tiite
Committee, vol. 365, pp. 1-87, 2000.
4. T. Luping (2008). Engineering expression of the ClmConc model for prediction oi free anH t t
concrete.
"0. 8. pp.
Hinh 7. Truydn ion clo ti-ong mdi trudng bd tdng xi mang Portland 10 nam trong didu kidn ngSm nuoc
hoan toan 4. KET LUiiN
Da thanh cong trong xay dung mo binh truyen dm kei hpp truydn chdt cho bai loan lan truyen hai chidu ion clo trong be tdng xi mang Portiand. Da so sanh truydn am trong hai tiTidng hop be long trong mdi trudng khdng khi hoan toan va trudng hgp mot phan ngap nude, mdt phdn sdy khd trong khong klii.
Kdt qua md hinh chi ra qua trinh thoat hoi nude tir be tdng ra ngoai moi trudng tai phdn khdng khi didn ra nhanh ban trong mdi trudng vira say kho, vira ngap nude. Cling nhu so sdnh lan bTjydn ion clo trong be long ngap trong nude hoan todn va be tdng mot phan ngap nude, mdt phdn sdy khd trong khdng khi. Kdt qua cho thdy lan huydn ion clo xam nhap vao be tong sau ban U-ong tiirdng hpp be tdng vira ngap nuoc.
vira hi sdy khd so vdi tiirdng bop bd tdng bao hoa hoan todn ti-ong mdi tiirdng ngap nude loan bo. Ddng Ihdi ti-ong trudng hgp ngap nuoe mot phdn. hien tugng lan tiiiydn ion clorua vdn didn ra tai phan be
chlonde ingress in submerged manne
\nient and Concrete Research, vol, 3« ,
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANQ 5/nrrt
KHOA HOC CONG NGHE 1092-1097, aug. 2008, doi: 10.iai6/j.cemconres.2008.
03.008.
5. 0 . E. Gjorv (2014). Durabihty Design of Concrete Structures in Severe Environments-Second Edition. CRC Press, 2014.
6. O. Amiri, A Ait-Mokhtar, H. Sleiman, and P. -T.
Nguyen (2015). Chloride Transport m Unsaturated Concrete. In Stmcture Design and Degradation Mechanisms in Coastal Environments, John Wiley &
Sons, Ltd, 2015. pp. 161-196.
7. A. Kumar (2010). Water flow and ti-ansport of chloride in unsaturated concrete. University of Saskatchewan, Saskatoon, Canada, 2010.
8. L. Wang and J. Bao (2017). Investigation on chloride penetration into unsaturated concrete under short-term sustained tensile loading. Mater Struct, vol. 50, no. 5, p. 227, oct. 2017, doi: 10.1617/sll527- 017-1095-6.
9. J. Geng, L. Li, and Y. Wang (2015).
Modelling of chloride penetration in unsaturated concrete. Advances m Cement Research, vol. 28, no.
1, pp. 51-61, sep. 2015, doi: 10.1680/adcr.l5.00003.
10. V. Q. Tran, H. L. Nguyen, M. V. Nguyen, H.
N. Nguyen and Q. Hung (2019). Drying Process Simulation of Unsaturated Concrete Exposed to Air Condition. International Journal of Engineenng and Advanced Technology, vol. 8, no. 5, pp. 1118-1121, 2019.
11. J. Bear (1972). Dynamics of fluids in porous media. Amencan Elsevier Pub. Co., 1972.
12. V. Genuchten (1980). A Closed-fonn Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils 1. Soil Science Society of America Journal, vol. 44, no. 5, pp. 892-898, 10/01 1980, doi:
10.2136/sssajl980.03615995004400050002x.
13. M. Mainguy (1999). Modeles de diffusion non lineaire en milieux poreux. Applications a la dissolution et au sechage des materiaux cimentaires.
Ecole Nationale des Ponts et Chaussees, 1999.
14. T. Xu, N. Spycher, E. Sonnenthal, L. Zheng and K. Pruess (2011). TOUGHREACT User's Guide:
A Simulation Program for Non-isothermal Multiphase Reactive Transport in Variably Saturated Geologic Media, Version 2.0, p. 240, 2011.
TWO-DIMENSIONAL SIMULATION OF CHLORIDE INGRESS INTO UNSATURATED CONCRETE Tran Van Quan, Nguyen Quang Hung Summary
Remforced corrosion due to chlonde is the most cause of damage and detenoration of concrete structures, especially for structure in the manne environment and exposing to unsaturated condiUon Therefore, this investigaUon focuses on the development of a two-dimensional model of coupled moisture-ion transport in Portland concrete. The numencal results show that, tbe process of moisture transport and chlonde ions penetration takes place more strongly tn unsaturated condition, thereby causing higher risk of corrosion.
The model can successfiilly determine tbe effective saturation zone and chlonde concentration zone in unsaturated concrete. These zones are curved areas in the case of concrete partly submerged in water and partly in the air. Tbe zones are rectangular in shape, changing over depth as a one-dimensional model for submerging completely in water or complete exposure to air.
Keywords. Moisture transport, chloride penetration, Portiand concrete. Reinforced corrosion. Simulation.
Ngudi phan bidn: PGS.TS. Hodng Phd Uyen Ngay nhan bdi: 27/3/2020
Ngdy thdng qua phan bidn: 27/4/2020 Ngdy duydt dang: 4/5/2020
