KHOA H O C - C O N G N G H I . 62niimVl^nKhoatKiciaC6neTigheGTVT
Nghien cuu thuc nghiem phuong phap thiet ke hon hop be tong nhya Superpave
I ThS. LUU NGOC L A M ; T S . L A M H Q U QUANG;ThS. CAO ANH T U A N Vien Khoa hoc vd Cdng nghe Giao thdng van tdi
TOM TAT: Thiet ke hon hop be tong nhya (BTN) Superpave co tinh ke thi/a phuong phap thiet ke BTN Marshall, tuy nhien co nhieu diem mdi, c6 xem xet c l thude tinh nirt do mdi, nUt do nhigt do thap, bien dang vTnh cCfu cda BTN. Bai bao phan tich cac d§c trung CCT b^n cua phuong phap thiet ke hon hop BTN Superpave va mdt so ket q u i nghien cuu thye nghiem trong phong
TO KHOA: Be tong nhya, nut mdi, ndt do nhiet dp ABSTRACT: The Superpave mix design method inherits Marshall mix design method, but there are many new features that take into account fatigue cracking, low temperature cracking, permanent deformation of asphalt concrete This paper analyses the fundamentals of Superpave mix design method for hot mix asphalt and some research test results in laboratory.
KEYW/ORDS: Asphalt concrete, fatigue cracking, temperature cracking.
I.OATVANO^
Mat dudng mem (dien hinh la mat dUdng BTN) dUoe ap dung rdng rai tren the gidi hien nay. Chat lUpng BTN phu thude vao nhieu yeu td, trong dd ed the ke den thiet ke hdn hap BTN. Tren the gidi hien cd hai phuong phap thiet ke hdn hap BTN dang dupe ap dung phd bien la:
Phuang phap thiet ke Marshall va Phuong phap thiet ke Superpave.
Trude khi phuong phIp Superpave ra ddi, phuong phap thiet ke hon hop BTN theo Marshall dupe ap dung rdng rai d My, nhieu nude tren the gidi {chau Au, chau A va dViet Nam). PhUong phap nay dupe phat trien bdi Bruce Marshall thude co quan dudng bd bang Mississippi vao khoing nam 1939, sau dd dupe to hop quan sy My cai tien va dugc hoan thien de trd thanh qui trinh ky thuat nhUASTMD1559vaAASHTOT245 nhu ngay nay.
Nam 1987, chuong trinh nghien edu chien lupe dudng d td (SHRP) dugc tien hanh n h i m muc dieh xay dyng tieu ehuan thi nghiem va phan loai mdi cho nhya
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dudng, de xuat mdt phuong phap thiet ke hon hop BTN mdi ed xet tdi quan he chat che gida cac thi nghiem trong phdng va dieu kien lam viec eua ket cau BTN d hien trudng dijgc goi ten la Superpave (Superior Performing Asphalt Pavement). Superpave la mdt trong nhOtng san pham noi bat eua SHRR Superpave dupe then khai se giup cho eae ky sU, nha thau dudng bd cdng eu de thiet ke BTN mat dUdng sao cho lam viec tdt hPn dudi tae ddng cua nhiet dp va lUu lUpng xe cd t l i trpng nang.
Superpave la phuang phap da dUpc eli thien hon so vdi cac phuang phap hien hanh trong viec chi rd tinh chat eua nhua dUdng va cot lieu trong thiet ke va phan tieh hdn hpp BTN, dy bao duae kha nang lam viee cua mat dudng. Phuong phap thiet ke Superpave hien dupe ap dung phd bien tai Hoa Ky, Canada va duoc the gidi danh gia la cd co sd khoa hpe.
Hien nay, Vien da trien khai thUe hien De tai cip Bd 2017, Ma sd DTI 74058 "Nghien cuti Ung dung phUOng phap thiet ke hon hpp BTN Superpave phu hop vdi dieu kien Viet Nam". Bai b i o trinh bay mot sd ket q u i nghidn cUu eua De tai DTI 74058.
2. NGUYEN TAC T H I ^ T K^ HdN HOP BTN SUPERPAVE
Cdng t i c thiet ke hon hop BTN theo phuang phIp Superpave nhIm myc dich tim ra ham lupng nhya tdi Uu yng vdi hdn hpp cot lieu da chpn. Viec thiet ke phli tuin theo nguyen t i c thiet ke can b I n g BMD (Balanced Mix Design) cac dae trung the tich - do nhay am, kha nang chdng lun vet banh xe va kha nang chdng ndt (Hinh 2.1) vdi cac yeu eau sau:
-Tat el cle vat lieu sd dung (da dam, cIt, bdt khoang, nhua dudng) deu p h l i thda man cle chi tieu eP ly theo quy dinh cua AASHTO M323-15;
- Dudng cong cap phdi cua hon hop edt lieu sau khi phdi tron phai nam trong gidi han cua dUdng bao cap phdi quy dinh cua AASHTO M323-15.
- Ham lupng nhUa tdi Uu lya chpn p h l i thda man elc ehi tieu lien quan den dae tinh the tich (dp rdng dd, dp rong edt lieu, dp rdng lap day nhya, %Gmm tai sd vdng xoay ban dau, %Gmm tai sd vdng xoay Idn nhat...), eae chi tieu thi nghiem d i e tinh cp hpe theo Superpave (dp nhay am eua BTN, kha nang chdng lun vet banh va kha nang chdng nut...).
KHOA HOC - C d N G NGHE
So 10/2018
Hinh 2.1: Sa do nguyen ly thiet kehSn hop can bang BMD
S.TRlNHTlTTHllTKfHdN HOP BTN SUPERPAVE Trinh tUthiet ke hon hop BTN theo Superpave duoc tien hanh theo elc bude nhu md ta tai so dd khdi d Hinh 3./,tdm t i t nhUsau:
- Bude 1: Lya chpn edt lieu va nhya dUdng.
- Bude 2:Thiet ke lUa chpn cap phdi tdt nhat.
- Bude 3:Thiet ke lUa chpn ham lupng nhua tdi Uu.
-Bude 4: Danh g i l dp nhay am.
- Bude 5; D i n h gia k h i nang chdng lun vet b l n h xe va kha nang chdng nut.
4. K I T Q U A N G H I E N CCrU THliC NGHI$M THI^T K £ BTN THEO SUPERPAVE T R I N C A C T A P MAU LLTA CHON
Muc dich eua viec trien khai nghien cdu thuc nghiem nay n h l m danh g i l tinh phu hap cua vat lieu ( d l dam, eat, bdt khoing, nhya dudng); cua hon hpp BTN khi ap dung phuang phap thiet ke hon hap BTN theo Superpave, ed so vdi phuong phIp thiet ke hdn hop BTN theo Marshall de dua ra cac khuyen nghi lien quan. Ket qua thd nghiem la CO sd dua ra dupe kien nghi, dieu kien deap dung phuong phIp thiet ke hon hop BTN theo Superpave tai Viet Nam.
Viec trien khai thuc nghiem thiet ke hdn hpp BTN theo Superpave dUoc tien hanh theo cac bude quy djnh tai AASHTO M323-15 (Thiet ke the tieh hdn hop BTN theo Superpave) va AASHTO R 35-15 (Hudng dan thiet ke the tich hon hap BTN theo Superpave).
De tai da tien hanh phan tieh, lya chpn eae thdng sd dau vao: Cap phdi, loai nhya dUdng, loai vat lieu thd nghiem va thiet ke quy hoach thye nghiem de xae djnh sd mau/thi nghiem phu hpp d i m b i o ket qua cd dd chum, dp tin cay cao ma van trong pham vi kinh phi cCia detai, chi tiet nhu sau:
- Ve cap phdi: Lya chpn hai kich cd danh djnh Idn nhat(19mmva 12.5mm).
- Ve nhua dUdng PG phu hop vdi lUu lUpng xe lya chpn: Dy kien eae mie nhua PG 64, PG 76, PG 82 theo tieu chuan phan loai nhya dudng PG (ket q u i nghien cdu cua Detai DTI 54015), ddng thdi sddyng ket qua nghien eyu eua De tai cap Bd 2017, Nghien eyu d i n h gia elc cht tieu eua nhUa dUdng 40/50,60/70 va elc loai nhya dUdng polymer dang ap dung tai Viet Nam theo tieu chuan phan cap nhya dudng PG do ThS. Lam HUu Quang lam chu nhiem de tai, de lya chon cle loai nhUa dUdng PG eho thuc nghiem.
- Ve loai vat lieu thy nghiem; LUa chpn ba ngudn gdc edt lieu khac nhau (edt lieu da vdi, da bazan khu vUe phia Bic va da andesitdinh bam kem khu vUc Nam mien Trung).
- Ve mdc luu lupng xe thiet ke: Dy kien lya chpn hai mdc luu luang xe thiet ke la (0.3 - 3) trieu ESALs va >30 trieu ESALs.
- Ve thiet ke hon hop BTN:Thiet ke hdn hpp BTN theo Superpave va ed so sanh ddi ehUng vdi thiet ke hon hpp BTN theo Marshall.
Viee lay mau, ma hda mau va kiem solt mau dupe thUc hien theo dung quy trinh de d i m bao tinh minh bach va ehinh xae.
Sd lupng mau thi nghiem dupe dUa ra trong Bang 4. h Bing 4.1. SSmdu thi nghiem vdi nguon goc di dim, loai BTN,
loai nhua vi mik luu Iuong xe thiet ki
Hinh 3.1: So do khoi cac buac thiet kehon hop BTN theo Superpave
4.1. Ket qua thiet ke hon hcrp BTN theo Superpave Ket q u i nghien edu thUc nghiem trong phdng phuong phap thiet ke hon hpp BTN theo Superpave dupe dua ra tai Bang 4.2, Bang 4.3 va Bdng 4.4.
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KHOA HOC-CdNG NGHE . 62niimVienKhoatv?cuclCdngngh$GTVT Bang 4.2 Thanh phan hat ciia cap phoi thinghii
Bing 4.3. Tong hop kit qui thiet kehon hop BTN12.5 theo Superpave
cap phdi thiet ke theo Superpave va tien hanh due mau de xae dinh ham Iuong tdi Uu theo Marshall).
- Myc tieu thd hai: Xlc dinh so cdng dam nen theo Marshall tUOng dUOng vdi sd cdng dam xoay theo Superpave de dat dugc cac dac trUng the tieh eua hon hpp BTN gidng nhau (gid nguyen cap phdi thiet ke va ham luang nhua tdi Uu thiet ke theo Superpave, thay ddi so cdng dam nen Marshall, xlc dinh sd chay dam tuong dng vdi dp rdng du4%).
Ket qua nghien edu thye nghiem trong phdng so sinh ham lUong nhua toi Uu hdn hpp BTN thiet ke theo Superpave va Marshall dupc dUa ra tai Bdng4.5 va Bdng4.6.
Bang 4 5. Tong hop ket qua so sanh ham Iuong nhua toi uu BTNJ 2.5 thiet ke theo Superpave va Marshall
Bing 4.6. Tong hap ket qui so sanh ham Iuong nhua tdi uu BTN19 thiet ke theo Superpave va Marshall
Ham lUdng nhua
Superpave Marshall
(Superpave-Marshall)
BTN19+PG64 (0,3-3)«10'ESALs Da vdi
4.90 4.95 -0.05
Bazan 4.95 5.00 -0.05
Andesite 480 490 -0.10
Nhdn xet: CIc chi tieu ca ly eua hdn hop BTN12.5 thda man theo quy dmh.
Bing 4.4. Tong hap ket qua thiSt kehon hop BTN19 theo Superpave
l9-PG641tappholvU«;
Ket qua nghien cdu thye nghiem trong phdng so sinh cdng dam nen hon hop BTN thiet ke theo Superpave va Marshall dupe dua ra tai Bdng 4.7 va Bang 4.8.
Bang 4.7. Tong hop ket qui dp rSng duBTNlZ.S vol so chay dam Marshall
m:^
Bang 4.B. Tong hop ket qua dd rong duBTN19 vdi so'chay dam Marshall
/V/idnxef;Caeehitieucalyeua hdn hppBTN19thda man theo quy dinh.
4.2. Ket quS thiet ke hon hop BTN theo Marshall doi chumg
Muc tieu nghien cdu so sanh ddi chyng nay gdm hai ndi dung chinh:
- Muc tieu thy nhat: Cd dupc thdng sd djnh lUdng ve sU khIc nhau trong ham lupng nhya thiet ke xac djnh theo phuong phIp Marshall va phuong phap thiet ke theo Superpave cho eae hon hop khac nhau (giU nguyen 32
So chay dam
75 90 120 150 So chay dam taong irng vdi do
ronq dLf4%
Do rong dU PG64,(0,3-3)»10'ESALs Da vdi
4.03 3.52 2.49 1.49 82
Bazan 4.09 3.70 2.61 1.65 80
Andesite 4.20 3.65 2.70 1.72 83
4.3. Phan tich thong ke vdi mCfc lUu lUcmg nhe (0.3 - 3 trieu ESAL]
KHOA H O C - C d N G NGHE
So 10/2018
4.3.1. Phan tieh vdi ham luang nhua thiet ke Thiet ke thye nghiem DoE (Design of Experiments) va phan tich thong ke vdi phan mem Minitab 18 d dd tin cay 95%, mdc y nghTa a = 5%. Thiet ke thi nghiem tong q u i t (General full factorial design). Phan tich phuong sai ANOVA va phan tich hau djnh phIt hien sai khac theo chul'n Tukey.
Cac bien dau vao cua thiet ke thye nghiem: 3 bien:
- Loai BTN: 2 loai la BTN12.5 va BTN19;
- Loai da: 3 loai la vdi, bazan va andesite;
- Phuang phap thiet ke (PPTK): Hai phuong p h I p la Superpave va Marshall.
Ham lupng nhUa thiet ke la ham dau ra phu thude cle bien. Ket q u i phan tich ANOVA cd y nghia thdng ke vdi he sd p « 0 . 0 5 va he so xlc dmh dieu chinh R^^^ = 97.60%.
a) - Bieu do ham lugng nhija phij thu$c 3 bien Main Effects Pbt for HL nhi/a (%)
b) - Bieu do anh hudng cac bien den ham luwg nhi/a thiet ke Hinh 4.1
Hinh 4.1b the hien anh hudng eae yeu td den ham Iuong nhua. Anh hudng Idn nhat la loai hdn hap BTN, BTN12.5 cd cap phdi min hon nen ham lupng nhya nhieu hon BTN19. Phuong phap thiet ke eijng c d l n h hudng cd ynghla thdng keden ham lupng nhya, BTN thiet ke theo phuang phap Marshall cd ham luang nhya Idn hon so vdi thiet ke theo phuang phap Superpave. Loai d l cung c d l n h hudng den ham lUOng nhya, trong ba loai thi BTN sydung da bazan cd ham luang nhUa Idn nhat, BTN sd dyng d l vdi cd ham Iuong nhya nhd nhat.
4.3.2. Phdn tieh vdi cdng dam nen
Be so sanh cdng dam nen theo phuong p h I p Marshall phai tang nhuthe nao de dam bao dp rong thiet ke 4% ddi vdi hon hap da thiet ke theo phuong p h I p Superpave tien hanh phan tieh thue nghiem nhu sau:
Cac bien dau vao cua thiet ke thye nghiem: 2 bien:
- Loai BTN; 2 loai la BTN12.5 va BTN19;
- Loai da: 3 loai la vdi, bazan va Andesite.
Cdng dam nen Marshall (so chay dam) de dat do rdng thiet ke la ham dau ra phu thude cle bien. Ket q u i the h\endHinh42a, nhan thay ddi vdi mdc luu Iuong nhe sd chay dam nen de dam b i o BTN cd dp rong 4% nhu thiet ke Superpave thi deu Idn han hoac b^ng 75.
3} - Bieu do cong dam nen cac lo^i BTN
Mam Effecb Plot for So chiy
b) - Bieu da anh hudng cac bien den cong dam nen Hinh 42
BTN19thdhan nen ddi hdi sd chay dam p h l i nhieu hon. Loai d l cung cd I n h hudng den cdng dam nen. Ddi vdi da bazan va da andesite ed dp cdng cao, xu xi, sac canh hon nen ddi hdi cdng dam nen cao han da vdi nhU Hinh 4.2b.
4.4. Phan tich thong ke vdi mOTc lifu lUtfng nang (>30 trieu ESAL)
4.4.1. Phdn tieh vdi ham luang nhi/a thiet ke Thiet ke thye nghiem DoE (Design of Experiments) va phan tieh thong ke vdi phan mem Minitab 18 d dp tin eay 95%, mdc y nghla a = 5%. Thiet ke thi nghiem tong quit (General full factorial design). Phan tich phupng sai ANOVA va phan tich hau dinh phat hien sai khac theo chuan Tukey.
Cac bien dau vao cua thiet ke thye nghiem: 3 bien:
- Loai da: 3 loai la vdi, bazan va Andesite;
- Loai nhya: 2 loai la PG76 va PG82.
- Phuang phap thiet ke (PPTK): Hai phUOng phIp la Superpave va Marshall.
Ham lupng nhua thiet ke la ham dau ra phy thude cac bien. Ket q u i phan tieh ANOVA ehi ed phupng phap thiet ke cd y nghia thdng ke vdi he sd p « 0.05 va he sd xac dinh dieu ehinh cua md hinh R^^^ = 94.85%. BTN thiet ke theo phuong phIp Marshal! ddi hdi ham lupng nhua phai cao hon so vdi phuong phIp Superpave mdi d i m b i o dp rong thiet ke 4%.
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KHOA H O C - C O N G NGHg - 62 ndm Vt^n Khoa tipcva Long ngh^uivt
Hinh 4.3: Bi4u dS ham Iuong nhua thiet keBTN12.5 4.4.2. Phdn tich vdi cdng dam nen
De so sinh cdng dam nen theo phuong phIp Marshall p h l i tang nhu the nao de d i m b i o dp rdng thiet ke 4% ddi vdi hon hpp da thiet ke theo phuong phap Superpave tien hanh phan tieh thue nghiem nhu sau:
Cac bien dau vao cua thiet ke thuc nghiem: 2 bien:
- Loai da: 3 loai la: Vdi, bazan va Andesite;
- Loai nhua: 2 loai la PG76 va PG82.
Cdng dam nen Marshall (sd chay dam) de dat dp rdng thiet ke la ham dau ra phy thude elc bien. Hinh 4.4a the hien cdng dam nen (sd chay dam) theo phuang phap Marshall de BTN12.5 sau khi thiet ke dat duac do rdng 4%.
Nhan thay cdng dam nen eua tat ea ele loai da vdi cac loai nhya deu Idn hon so vdi cdng dam nen 75 ehay quy dinh theo Marshall.
a) - Bieu 66 cong dam nen BTNI2.5
Mam Effects Plot for So ehay
b} - Bieu da inh hudng cic bien d^n cong dam nen Hinh 4.4
Hinh 4.4b the hien Inh hudng eua eae bien den cdng dam nen, nhan thay ddi vdi nhua PG82 co dp quinh cao hon nhua PG76 nen cdng dam nen cung ddi hdi cao hon.
Loai da cd anh hudng den cdng dam nen theo thUtugilm dan cdng dam nen ddi vdi cac loai da: Vdi, bazan, Andesite.
5. K^T L U A N , K I ^ N N G H ;
-Thiet k^ hon hpp BTN theo Superpave cd nhi^u npi dung ducjc ke thda t d thiet ke Marshall (cac ehi tieu ky thuat vdi edt lieu; cap phoi hdn hpp edt lieu; cac chi tieu ve dac tinh the tieh nhu dp rong dU, dd rdng edt lieu, dd rdng lap day nhya).
- Thiet ke hon hop BTN theo Superpave cd nhdng diem dac trUng td ra ed Uu diem hOn so vdi thiet ke Marshall, the hi§n tai elc npi dung: Sd dung nhUa dudng PG phu hpp vdi nhiet dp mdi trUdng cua vung du an va hieu ehinh mac nhya PG theo dac tinh ddng xe; sy dung dam xoay tao mau BTN; quy djnh ve cap phdi thd, cap phdi mm; quy djnh dd chat yeu cau dng vdi cle vdng xoay Nini, Ndes, Nmax; ty sd B/D; he sd cUdng dp ep ch^ ITSR.
- Viee thiet ke hon hpp BTN theo Superpave tai Viet Nam phli tuan theo nguyen tSe thiet ke cIn bSng BMD (Balanced Mix Design) cac dae trUng the tieh-dp nhay am, kha nang chdng lun vet b l n h va kha nang chdng nUt.
-Thdng qua ket qua nghien edu thye nghiem trong phdng, nhdm nghien edu da nam vdng dugc cdng nghe thiet ke BTN theo phuong phap Superpave (yeu eau vat lieu, cap phdi, phuong p h I p thiet k^ hdn hop, cle chi tieu d i n h g i l chat Iuong BTN...) va nhan thay:
+ BTN thiet ke theo phuong p h I p Marshall can ham luang nhya cao hon so vdi thiet ke theo phuong phap Superpave;
+ Cdng dam nen cua phuong phap Marshall cd dinh 75 chay/mat la khdng du de BTN dam b i o dd chat, chju t i c dyng eua luu luong xe. Cdng dam nen cua phuong phap Superpave cao hon phuang phIp Marshall.
-I- De cd the sd dyng phuong phap Marshall thiet ke hdn hpp BTN eho dudng chiu t l i trpng nang thi can co nhdng nghien cdu tang cdng dam nen.
+ Phuang phap Superpave da xet den I n h hUdng cua luu lupng den cdng dam nen, nhu vay hdn hpp BTN thiet ke theo phuong p h I p nay d i m b i o kha nang chiu luc, chdng lai bien dang khdng hdi phye.
Tai lieu tham khSo
[1]. Luu Ngpc Lam, Vu Ddc Chinh, Nguyen Quang Phuc va nnk (20) S), Bdo cao tong ket KHCN de tdi cap Bg ndm 2017 "Nghien cdu Ung dung phuang phdp thiet kehon hap BTN Superpave phu hop vdi dieu kien Viet Nam".
[2].AASHrOT32S-20}5.SuperpaveVolumetrielVHxDesign.
[3]. AASHTO R 35-2015, Practice for Superpave Volumetric Mix Design for Asphalt Mixture.
[4]. NCHRP Report 567 (2006), Volumetric Requirements for Superpave Mix Design. Transportation Research Board, Washington, D.C.
[5]. NCHRP Report 492 (2016), Performance Specifications for Asphalt Mixtures, Transportation Research Board, Washington, D.C.
Ngay nhan bhii 20/8/2018 Ngay chap nhan 6ing: 11 /9/2018 Ngudi phdn bien: TS. Biii Ngoc HUng
ThS. TrSn Trung Dung
