KHOA HOC CONG NGHE
So 05/2020
Nghien cuu thae nghiem danh gia
cuong (36 khang cat trircrt giOa hai lop be tong nhua tai mpt so du an o Viet Nam
I PGS. TS. OAO VAN DONG; ThS. NCS. BUI THj QUYNH ANH Trudng Dgi hgc Cong nghe Qiao thong vdn tai
• PGS.TS. NGUYEN QUANG PHUC Trudng Dai hgc Giao thong van tai
TOM TAT: Bai bao gidi thi#u ket qua nghien cdu thuc nghiem danh gia cudng do khang cat truot giua hai ldp be tong nhua (BTN) cCia cac mau khoan hien trudng tu mot so du an dudng nhua dang khai thae d Viet Nam Nghien cdu dupe tien hanh tren thiet b| cat cd xet d"en ^nh hudng cua ap luc phap tuyen duoc che tgo tai Viet Nam T u KHOA: Cudng do khang c§t truot giua hai Idp, m^t dudng be tong nhua, mau khoan hien trudng, ap luc phap tuyen
ABSTRACT: The article shows the experimental results on determing interlayer shear strength of corings collected from some asphalt pavement in Vietnam The studywas conducted on shear test with normal pressure which was produced in Vietnam KEYW/ORDS: Interlayer shear strength, asphalt pavement, coring, nomal pressure
I.OATVANOE
Do cae yeu cau ve ehju iUe nen ket eau mat dUdng BTN thudng duoe bd tri nhieu tang Idp vdi eac nhiem vy khac nhau va thudng dupe thi cdng thanh tdng Idp. Khi dinh bam gida cac Idp BTN khdng dupe dam b^o se xuat hien hien tugng cat trUert tai vi tri tiep xue anh hUdng den kha nang khai thae mat dudng. De xac dinh sde khang cat truot gida cac Idp BTN, cd hai phuong phap thi nghiem pho bien bao gdm thf nghiem cat khdng cd ap lUc phap tuyen va ed ap lUc phap tuyen. Thi nghiem cat khdng cd ap lUe phap tuyen la thi nghiem c5t ph^ng thuan tuy sd dung thiet b\ nhu Leutner, Leutner cai tien, LPDS, FOOT.
Thl nghiem e^tcdap luc phap tuyen sddung cae thiet bl nhu LISST, ASTRA, NCAT la thi nghiem ed hai thanh phan luc tac dung gdm luc cat va lUc nen doe true. Xet ve dieu kien xe chay thue te tren dUdng, thi nghiem cat cd ap lUc phap tuyen dugc coi la phu hop hon [6].
Nhdng nam gan day, chat lugng mat dudng BTN d nudc ta da dUOc cai thien dang ke, Tuy nhien, thue te eho thay d mdt s d d u a n da xuat hien ty le dang ke huhdng mat dudng ngay d giai doan mdi dUa vao khai thae, Cac dang hu hdng do nguyen nhan eat trUert gida hai Idp BTN chiem so luong Idn nhu ndt truot, xd ddn, han liin vet
banh xe, dViet Nam, tac gia Nguyen Quang Phuc [3] va Dao Van Ddng [2] da ed nghien cdu thuc nghiem danh gia eUdng do sde khang eat trucft gida eae Idp BTN tren cac mau khoan hien trudng tai mdt sd duan. Nghien cUu dugc thuc hien tren thiet bi Leutner va Leutner cai tien.
Day la nhdng thiet bt c^t phang thuan tiiy khdng cd ap lUe phap tuyen, tdc la chUa xet den ap luc thiing ddng cua banh xe nhutren thue te. Hien nay, nhdm nghien edu da che tao thanh cdng thiet bj cat cd xet den anh hudng cua ap lue phap tuyen. Qua ket qua cua mdt sd nghien edu cho thay thiet bi hoat ddng hieu qua, dn dinh va ed the sd dung trong eae nghien cdu lien quan [4]. Do dd, viee nghien cdu danh gia cudng do khang cat trUgt gida cac Idp BTN eua eac mau khoan hien trUdng td mdt sd dU an dien hinh d Viet Nam sd dung thiet bi eat ed xet den anh hudng eua ap lUc phap tuyen la can thiet,
2. NGHIEN CU^U THl/C N G H | £ M X A C DjNH Cl/dNG D d C H 6 N G CAT G I ^ A C A C LQP BTN
2.1. Ke hoach nghien cu\i
De danh gia eudng dp chdng eat gida hai Idp BTN thuc te dat duge trong ket cau ao dudng mem, 4 du an da dupe lua chgn thuc hien. Trong do, Du an 1, HI thudc tuyen dUdng cap 3 - ddng bang ddi, DU an II, IV thudc tuyen dudng cap 2 - ddng bang ddi, eae dU an lay mau deu thudc khu vue mien Bae Viet Nam, Bdng 2.1 the hien sd luong mau thi nghiem lay tuong dng vdi mdi du an.
Bang 2.2 the hien ke hoach thi nghiem.
Bing Z. 1. Tong hpp sd'lupng mau va dae diem ket cau
STT
1
2
3 4
Ten d U a n
Dl/
an 1 DU anil D u a n III D u a n
iv
D a e d i e m ket ca u
BTNC 12,5/19
BTNC 12.5/19
BTNC 12.5/19
BTNC 12.5/19
Loai/ti \k tudi dinh b a m (l/m^) CRS-1/0,5 CRS-1/0 5
CRS-1/0 5 CRS'1/0 5
Thdi gian khai thae (thdng)
64 25
1 16
So m a u
60 60 60
60 Tdng so mau thi nghiem , 240 Ghi chO- Ket cau BTN hai lop- lop tren day Scm, lop duni day 7cm Cac miu khoan co kich thuoc dujng kinh 10cm, chieu cao / 2cm
47
KHOA HOC CONG NGHE
So 05/2020
Bang 2.2. Ki'hoacb thi nghiim Thi nghiem tren cac m i u cua cac dif an khac nhau (khoan tai vi tri khdng hu hong)
Duan Nhiet dp thl nghiem (°C) Ap lUc phap tuyen (MPa)
4dUan 3 mde
1,11, III, IV 25,40, eo^c 5 mde 0, 0,14,0,2,0,4,0,6MPa
Idp cua eac du an trong khoang 0,01 - 0,45MPa, chuyen v i t d l , l -4,8mm,
2.2. Qua trinh thi nghiem xac djnh cUdng do chdng cat giufa cac Idp
Qua tnnh khoan lay mSu dUde tuan thd theo chi dan TCVN 8860:2011 [1], Mau thd khoan tai hien trudng sau khi dugc eat bd phan mdng dudng se dUOe capping be mat, Mau dupe bao dudng trong mdi trUong nude tdi thieu la 02h d eae nhiet dp 25", 40*' va 6QPC. Thi nghiem cat dupe tien hanh theo chi dan AASHTO TP 114-15 [5].
Thl nghiem dUOe thUe hien tren thiet bt cat ed ap lUc phap tuyen da che tao vdi toe do khdng doi 2 54 mm/
mm cac eap ap lUe phap tuyen la 0 0 14 0,2 0 4 0 6MPa
Hmh 2 1 Khaan mau hien truong va thi nghiem xac dmh cuong do eat truot gida hai lop BTN T(\ sd eudng do eat trUOt gida hai Idp BTN cua moi mau thd dugc tinh theo cdng thdc sau:
IS5 = r = -P Trong do:
o
ISS, T - Cudng do chju cat gida cae Idp, MPa;
P - LUc pha hoai idn nha't tac dung len mau, N;
D -Dudng kfnh m i u , mm.
2.3. Ket qua thf nghiem
Ket qua nghien cdu xac dinh cudng dp chong cat va ehuyen vi gida hai Idp BTN cua cac mau khoan tai eae d u an dugc the hien tren cac Hinh 2.2, Hinh 2.3, Hinh 2.4.
Tren hinh cho thay, d 25''C, cudng do chdng cat gida hai Idp cua cac du an trong khoang 0,26 - 0,72MPa, ehuyen vi t d 0,9 - 2,7mm. d 40''C, cUdng dp chdng cat gida hai ldp cua cac du an trong khoang 0,07 - 0,53MPa, chuyen vi t d 0,9 - 4,6mm, CJ eCC, cUdng do chdng eat gida hai
.' '-
Hinh 2.2. Bieu do thi'hiin quan he giua cudng dp chong cat giua hai Idp BTN va chuyen vld25°C
DVI-O DVID DVI-O
•i\\? Vlb'J j ! / i y i DY-l-O / l b ' D-/i-0 ODYJ-O
«b5 1W
• DVVOnBVIb' -DVJ-O J-lb"
-D'fi-O + DV3-0 ODV3-0 J-lb"
••i\y
-i\ av
"•DVj-Oma X D V K T D V K
•DVl-O Wb3
• m a 'iVlVa^
• n71-ll/li.3
chdng
«[)AI-0 I D A I . 0
XDAl-0 ) ; D A 2 - 0 BDA3-D
•1-DA2-0 -DA2-(1
• D . - \ M raDA3-0 DA3I1
cat
iPa iSMl',1
VIPJ
JSMPfl MPa MPii
38 MP^ MPa
\lP,i DWJJMPii D.AJ-O DAi|-0 DA 1-0
JSMPJ WFa WPa
Hinh 2.3: Bieu do the hien quan he giua cudng dp chdng cat gida hai Idp BTN ifa chuyin vi6'4ff'C
Hinh 2.4: Bieu dd the hien quan he gida cudng So chdng cat giua hai lap BTN va chuyen vi & 6CPC
3. PHAN TICH KET QUA THI NGHIEM 3.1. Danh gia cUdng do chdng cat gida cac Idp BTN Hinh 3.1 the hien ket qua eUdng dd chju eat trung binh eiia eae du an, De dang nhan thay tn sd cudng do chdng cat trung binh giam dang ke khi nhiet dd thi nghiem tang t d 25'*C len 60°C dtat ca cac du an Cu the, d eo^C, eUdng dd ehdng eat trUOt trung binh ciia cac du an giam 60,46% so vdi d 25^0
KHOA HOC CONG NGHE
So 05/2020
Hinh 3.1: Cudng da chiu cit gida hai Idp BTN eho eic mau hien trudng eho cac du an NgUOc lai, trj sd cUdng dd chdng c^t tang dang ke khi ap lue phap tuyen thi nghiem tang tdO den 0,6MPa d cac d u an. Cu the, cddng do chdng eSt trung binh d ap luc phap tuyen 0,6MPa tang 66,66% so vdi d OMPa, Mat khac, qua ket qua cung nhan thay rSng, d nhiet dd cao anh hudng cua ap lUc phap tuyen den cddng do chju cat rd rang va dang ke hdn rat nhieu so vdi d nhiet dd thap. 0 25°C, cUdng do chiu e i t trung binh khi thi nghiem vdi ap lUe phap tuyen 0,6MPa, tang 48,33% so vdi khi thi nghiem d a p lue OMPa, Khi nhiet do dat eO^C, eUdng do chm cat trung binh khi thi nghiem vdi ap lUe phap tuyen 0,6MPa,tang 94,12% so vdi khi thi nghiem d a p luc OMPa.
Phan tich danh gia ket qua thi nghiem c^t gida hai Idp BTN trong ket eau ao dUdng mem. Bang 3.1 the hien ket qua thi nghiem cudng dp chiu e^t gida hai Idp BTN trong ketcau ao dUdng mem d 4 dU an vdi cac cap hang ky thuat va thdi gian khai thae khac nhau.
Bing 3.1. Ket qui thi nghiem eudng dp ehiu cit gida hai Idp BTN trong ket cau ^o dudng mem 64 duin
Nhiet do l?Q
25°C
40"C AplUc (MPa)
0 0,14 0,2 0,4 0,6 0 0.14 0.2 0.4 0,6
O i r d n l T
(MPa) 0,29 0,30 0,34 0,51 0,57 0,10 0,12 0,18 0,33 0,38
c.
%
10.94 10,54 23,16 14,76 17,83 18,26 30,43 19,77 17/42 29.85
DUAnll T
(MPa) 0,34 0,36 0,39 0,59 0,63 0,13 0,19 0,22 0.39 0,44
C,
%
10,47 11,34 16,88 14,04 10,29 21,92 18,73 18,33 17,89 15,19
0 ( f i T
(MPa) 0,30 0,30 0,32 0,54 0.59 0,10 0,13 0,18 0,35 0,41
n l l l C.
%
9,43 7,20 18,58 21,21 18,23 2S,3S 24,33 19,77 19,10 27,23
Dili
T
(MPa) 0.32 0,35 0,39 0,56 0,61 0,12 0,16 0,20 0,37 0,45
nIV C,
% ,
11,41 15,99 14,35 1?,13 14,97 20.41 18,40 17,80 38,03 20,61
Nhiet at CC)
60°C Apluc (MPa)
0 0,14 0,2 0,4 0,6
D i f a n i 1 DiTanll
-
(MPa) 0,01 0,07 0,12 0,24 0,29
C, 1 T i C, Difanril T
% (MPa) % l(MPa) 19,26
34,99 39.18 32.63 24.06
0.03 0,11 0,19 0,29 0,34
24.51 19,77 27,44 21,99 24,96
0,02 0.09 0,15 0,25 0.36
C,
%
31,60 32,51 28,28 25,92 19.51
DlT an IV T C.
(MPa) % 0,02 0,10 0,17 0,27
28,84 25,82 22,53 17,89 0,37 1 20,82 Ket qua cho thay, vdi cac dUan cd cap hang ky thuat thap hon (Du an I va Du an III), cUdng do ehiu cat gida hai Idp BTN cung thap hon. Dieu nay cho thay, viee quan ly chat lugng thi cdng Idp dinh bam gida hai Idp BTN d nhdng du an ed cap hang ky thuat cao hon (Du an 11 va Du an IV) tdt hon so vdi nhdng dU an cd cap hang ky thuat thap hon (Du an I va DU an ill).
Theo ket qua nghien edu danh gia cudng dp chdng eat gida hai Idp BTN ciia Chuong trinh nghien cdu DUdng bd qudc gia Hoa Ky sd dung thiet bi LISST, thi nghiem d 25'*C, vdi hai mde ap lUe 0 va 0,14MPa ed he sd phan tan t d 2 - 58,9% [7]. Dieu nay eho thay, mdc dp phan tan eua eae ket qua thi nghiem t d cac mau hien trudng trong nghien edu nay tUOng ddng vdi ket qua nghien edu tren mau khoan hien trUdng sd dyng thiet hi LISST da edng bd. Ngoai ra, mdc do phan tan C^ the hien dp ddng deu trong ehat lUdng thi edng. Khi thi cdng ngoai hien trUdng rat khd quan ly chat lUOng va dam bao dong deu tren toan bd doan tuyen dai do cac nguyen nhan nhu mdc do tudi dinh bam (tudi khdng deu), be mat tUdi dinh bam (ed doan khd sach, nham hay cd doan ban, Udt, min...), thdi tiet... Vi vay, cac gia trj C^ thu dUpc t d thi nghiem tren eac mau khoan td hien trudng thudng cao hon nhieu so vdl cae mau ehe tao trong phdng thi nghiem,
Ngoai ra, t d ket qua thi nghiem cho thay, vdi eae td mau d eae DU an II va DU an IV vdi thdi gian da khai thae t d (6 - 36) thang, cudng dp chiu cat trung binh d 25''C cao hon 9,75%, d 40°C cao hon 17,39% va d dO^C cao hdn 11,76% so vdl cudng dd chju cat trung binh eua eac td mau lay d D u a n III vdi ketcau vda mdi thi cdng xong, Ket qua nay eho thay, sau khi thi edng xong hai Idp BTN neu cUdng dp chju cat ban dau dat dupe mdc do tdi thieu nhat dinh thi eudng dd ehju eat gida hai ldp se tang len theo thdi gian dudi tae dung dam nen cua cac phuong tien tham gia giao thdng, ket qua nay cdng hoan toan tuong ddng vdi ket qua nghien cdu ciia tac gia Stockert [8]. Tuy nhien, vdi Du an I (thdi gian khai thae 64 thang), cddng do chdng eat lai cho thay sU suy giam rd ret.
Cudng dp chdng cat d 25''C thap hon 16% so vdi cudng do trung binh eua cae duan khac, thap hon 18,18% khi d 40*'C va thap hon 20% khi ddO^C.ThUe te, trong qua trinh khoan lay mau va khao sat cho thay, tuyen dUdng nay tuy luu lupng giao thdng khdng Idn, nhUng thudng xuyen va cd nhieu xe tai nang chay qua, Td ket qua cho thay, thdi gian khai thae du doan cd the la mdt bien gay nhieu, can
49
3?Ri.
KHOA HOC CONG NGHE
So 05/2020
phai duoc xem xet anh hudng den cudng dp chdng eat truot gida eac ldp.Trong trudng hop nay, phep phan tich hiep phuong sai ANCOVA dugc lUa chgn de phan tich.
3.2. Ket qui phan tich hiep phUdng sai ANCOVA Phan tich hiep phuong sai (ANCOVA) la trUdng hop md rdng ciia phan tich phUdng sai mdt chieu khi bao gdm mdt hay nhieu bien lien tyc de giai thich bien ket qua, Phan tieh hiep phUdng sai dugc sd dyng de kiem chdng su khac nhau ve gia tri trung binh gida hai hay nhieu nhdm ddc lap. Ngoai ra, phan tich hiep phuong sai cdn cho phep chiing ta "kiem soat thong ke"doi vdi mdt bien t h d 3 (ddi khi cdn goi la bien nhieu . - confounding variable - hoae hiep bien - covariate)
anh hudng den ket qua.
Bang 3.2. Ket qui tong hpp phin tieh phuong sai ANCOVA Thong tin bien sd (Factor Information)
Yeu to Loai Mdc Gia trj
Apli/c Cddinh 5 0,00,0,140,0,200,0,400,0,600 Nhiet do Cddinh 3 25,40,60
Hiep bien Thdi gian khai thae Phan ti'ch phUOng sai (Analysis of Variance) Nguon BaetiTdo AdjSS Adj MS GlStrlF GiStriP ThBigi.nkh
ApUc Nhiet do Sai so Lack-of-FiI Sai so thuan T6n9
ithSc 1 4 2 185 41 144 191
0,00468 1,54705 2,29845 0,54534 0.13790 0,39604 4,92496
0,00468 0,55256 1,29672 0,00205 0,00314 0,00269
Tom t^t md hinh (Model Summary) S R-sq R-sq(adj)
3,39 0.091 154.02 0,000 385,26 0,000
1,19 0,475
R-sq(pred)
0,0542885 88,25% 87,56%
Ket qua phan tich ANCOVA thu dUOc ed R'^^ = 88,04%, Laek-of-Fit - 0,475 > 0,05. Qua ket qua eho thay, ap lUc va Nhiet dp deu cd p-value < 0,05 nen sUanh hUdng den cudng dd ehdng eat cd y nghia thdng ke, Tuy nhien, thdi gian khai thae ed p-value = 0,091 > 0,05 khdng cdy nghia thdng ke d mde y nghia dang xet (a = 5%), Dii vay, nhung neu d mUc y nghTa 10% thi thdi gian khai thae cd y nghia thdng ke,
3.3. Xac djnh y^'u to chinh anh hudng chinh den cUofng do chju cSt giuTa hai Idp BTN
Ngoai ra, tii Hinh 3.2, cac yeu td anh hUdng eho thay, eudng do ehdng c3t phy thudc chinh vao ap lUc va nhiet dp the hien bang dp ddc eua cac dudng quan he. Qua hai do thi tren cho thay, nhiet dd va ap lUe phap tuyen la hai yeu to anh hUdng chinh va nguoc lai thdi gian khai thae cd ft anh hudng den cudng do chju cat gida hai Idp BTN cua cac mau khoan hien trudng cae dU an dang xet.
Khi ap lUe tang thi cUdng do ehdng eat tang len, khi nhiet dp tang thi cUdng dd ehdng c^t giam rat nhanh.
NgUpc lai, khi ap lUc tang thi eudng dd chdng cat tang.
Cdn ddi vdi thdi gian khai thae, t d O l den 24 thang thi cUdng do chdng cat tang len nhung t d 24 thang den 62
thang thi cudng dp chdng cat lai gi^m di. Dieu nay cd the ly giai trong giai doan dau khai thae dudi tae dung eua tai trong dam nen thd cap mdc dp lien ket cua hai ldp tang len, nhung sau giai doan dau dUdi tae dung cua eac yeu td nUde (do am) nhiet dp nen cUdng dp ehdng cat giam di, day eung la xu hUdng khai thae ehung cua toan ket cau.
Hinh 3.2: Bieu do cac yeu to inh hudng den cudng do ehdng cat giira cac lop
4 . K £ T L U A N
Dd phan tan C^ trong eae thi nghiem vdi cac mau hien trudng Idn hOn rat nhieu so vdi eae mau trong phdng eua nghien cdu thuc hien tren cung thiet bj,
Ket qua phan tich ANCOVA cho thay thdi gian khai thae cd p-value = 0,091 > 0,05 khdng cd y nghTa thdng ke d mdc y nghia dang xet {a = 5%), Du vay, nhung neu d mdc y nghTa 10% thi thdi gian khai thae ed y nghTa thdng ke, Cd the thay, thdi gian khai thae, dUdi tac dyng cua tai trpng dam nen thd cap da cd anh hudng nhat dinh den dinh bam gida cac Idp va eUdng do chju cat giUa hai Idp BTN. Tuy nhien, trong pham vi nghien eiili, day dUOc eoi la bien nhieu, khdng phai bien dde lap,
Ap lue phap tuyen tang tUO den 0,6MPa trj sd cUdng dp chiu cat gida hai IdpBTN tang. Nhiet dd tang td25''C den eO'^C, eudng do chdng cat giam manh,
Nhiet dp la yeu td iinh hudng chinh den cUdng dp ehiu cat gida hai Idp BTN cua eae mau khoan tU hien trudng 4 duan.
Tai lieu tham khao
[1]. Bd GTVT (2011), TCVN 8860:2011 - BTN - PhUang phdp thd.
[2]. Dao Van Ddng (2016), Nghien cdu ddnh gid sde khdng cat trUgt cua cac ldp be tong asphalt trong ket cdu do dudng mem d Viet Nam, De tai DTI 54013 cap Bd GTVT,
[3], Nguyen Quang Phue va Tran Nam Hung (201 OJ, Nghien cdu cUdng do dinh bdm gida cdc Idp be tong asphalt trong ket cdu do dudng mem. Tap ehi GTVT, sd 10, tr.33-41.
[4], Bui Thj Quynh Anh, Dao Van Ddng va Nguyen Quang Phiie (20^9), Nghien cdu che tgo thiet bi xdc dinh cudng do cat gida cdc idp BTN co xet den dnh hudng cua ap IUc phdp tuyen. Tap chi GTVT, sd 4, tr. 32-35.
KHOA HOC CONG NGHE
[5]. AASHTO TPn4-15 Determining the Interlayer ShearStrength (ISS) of Asphalt Pavement Layers, chu bien.
[6]. Canestrari P va cac cdng sU (2005), Advanced testing and characterization of interlayer shear Resitance, Transport Research Record No (1929), tr.69-78.
[7], National Cooperative Highway Research Program {2012), NCHRP Report 712, Optimization of Tack Coat for HMA P/ocemenf, Washington DC.
[8]. Stokert U (2001), Schichtenverbund-Prufung and bewertungsh interground, strabe andautobahn.
Ngay nhSn b i i : 01 /3/2020 Ngay chap nhSn ddng: 24/3/2020 NgUdi phdn bi^n: TS. NguySn Ngpc U n
TS. Tran Ngoc HiAig
