PAVEMENT REHABILITATION using BITUMEN STABILISATION STATE OF THE ART

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1 PAVEMENT REHABILITATION using BITUMEN STABILISATION STATE OF THE ART 23 rd Road Pavement Forum Fern Hill Hotel, Tweedie, KZN Wednesday 9 th May 2012 Dave Collings UCD Technology LOUDON INTERNATIONAL

2 THE LONG TERM BEHAVIOUR OF BITUMEN STABILISED MATERIALS (BSMs) Understanding non-continuously bound materials UCD Technology Dave Collings Kim Jenkins LOUDON INTERNATIONAL tellenbosch

3 Rigidity Cement % Bound TG2 (2009) Cement stabilised Non-continuously bound 1 0 BSM Granular Asphalt Unbound Bitumen % 5 Flexibility Bound

4 FATIGUE CRACK PROPAGATION (Fracture mechanics) CONTINUOUSLY BOUND MATERIAL CRACK TIP STRESS CONCENTRATION Paris Law: Stress intensity factor at crack tip d c = A.K n d N Increase in crack length / load cycle NON-CONTINUOUSLY BOUND MATERIAL Similar to unbound granular materials

5 ATHENS CORINTH HIGHWAY, GREECE 200mm 300mm recycled 2.0% 2.3% foamed bitumen 1.0% cement 2002 NTUA MONITORING SECTION

6 NTUA FWD SURVEY DATA M R 15% Δ layer thickness 50% Δ layer stiffness? Time after construction (months)

7 REVISITED APRIL years after rehabilitation > ESALs ± vpd 15% heavy heavies / day (13 ton legal axle load) = 6.9 ESAL ADE ± / day ( 4 ESALs / heavy ) ESALs / year

day (13 ton legal axle load) 13 8 4 = 6.

8 NTUA MONITORING SITE PERMANENT DEFORMATION mm MEASURED 8mm DESIGN 20mm Time / Traffic 8 years 15 years

9 Cement % Rigidity 4 3 Cement stabilised NON-CONTINUOUSLY BOUND? SEMI-CONTINUOUSLY BOUND? 2 Bound? BOUND? 1 0 Granular Unbound Asphalt Bound Bitumen % 4 5 Flexibility

10 Meeting of the minds

11 2 MONTHS LATER...

14 The real problem 3 misa limit ( ESALs )

15 Typical SA pavement 40mm HMA 150mm G1 B cat road / wet climate 300mm C4 Treat G1 material with foamed bitumen 3 10 million < 3 million IS THIS REASONABLE??

16 TRANSFER FUNCTIONS The Effective Fatigue equation N EF = 10 [ (ε h/ε b )] The Permanent Deformation equation N PD.FB = 1/30 x 10 [k rd ps-1.628sr+0.68(cem/bit)]

708(ε h/ε b )] The Permanent Deformation

17 The Permanent Deformation equation N PD.FB = 1/30 x 10 [k rd ps-1.628sr+0.68(cem/bit)] Road category A = B = C = D = Relative density 0.78 to 0.86 Plastic strain 5 to 20 Stress ratio 0.1 to 1.0 MODEL Cement added % Bitumen added % % cement / 3% foamed bitumen N PD.FB = ESALs

625 Relative density 0.78 to 0.86 Plastic strain 5 to 20 Stress ratio 0.1 to 1.

18 The Permanent Deformation equation Use cement!! Cement added % Bitumen added % N PD.FB = 1/30 x 10 [k rd ps-1.628sr+0.68(cem/bit)] Road category A = B = C = D = Relative density 0.78 to 0.86 Plastic strain 5 to 20 Stress ratio 0.1 to 1.0 MODEL % cement + 0.5% foamed bitumen N PD.FB = ( x 10 6 ) ESALs

950 C = - 1.816 D = - 1.625 Relative density 0.78 to 0.86 Plastic strain 5 to 20 Stress ratio 0.

19 CLASSIFICATION SYSTEM (Page 49) Add cement!! MATERIAL CODE ITS* at 25 C (kpa) UCS at 25 C (kpa) FB4 FB2 FB3 FB1 * unsoaked ITS 40 C ITS SOAKED?? 150mm Ф

500 UCS at 25 C (kpa) 700 1400 1400 2000 FB4

21 Someone is out of step

24 BSM-foam sites (2010) (SANRAL Network) P243 Vereeniging N11 Section 8 Hendrina R27 Nieuwoudtville P504 Shongweni N7 Section 1

25 CONSTRUCTED IN 2001 BSM1 (crushed stone) 2.3% bitumen / 1% cement Design (J&G / Stellenbosch University): 7 x 10 6 ESALs Power Construction

26 After 10 X 10 6 E80 load repetitions + 22 LTPP / HVS data sets

27 2011 observations: Cracks observed Start of fatigue failure

28 Reality: ± 200m settlement / isolated cracking CONSTRUCTION DEFECT

29 2.5m 2.5m CLASSIC OVERLAP DEFECT

30 BSM-foam sites (2010) (SANRAL Network) R23 Mseleni Phelendaba N7 Section 1

31 R23 MSELENI TO PHELENDABA Constructed in 2002 AA Loudon & Partners / Space Construction

32 KEY COMMUNITY ACCESS ROAD +100km to closest G5 material source

33 19 / 6.7 mm double seal (after 3 years) Double slurry seal 250 mm BSM base (Blends of sand / gravel / silty-sand / crusher dust) Sand subgrade

34 ?

35 FATIGUE CRACKING 19 / 6.7 mm double seal 150 mm C4 base (Doorbank) 150 mm C4 subbase (recycled gravel wearing course) Sand subgrade

39 Philosophical argument? South Africa: KZN DoT (since 1996)

40 KZN: MR 63 (2004) 175 mm recycled 1% lime + 3% foamed bitumen 3 x 10 6 ESALs G5 / G6 weathered sandstone

41 Philosophical argument? South Africa: KZN DoT (since 1996) Ethekwini Metro (since 1997) Old Main Road, Pinetown M5 Westmead Industrial Area M5 Queensburgh FIFA World Cup projects Many many more...

42 BSM1 In situ recycled BSM1 (RA material) In plant mixed / paved

43 Philosophical argument? South Africa: KZN DoT (since 1996) Ethekwini Metro (since 1997) Other Provincial Main Roads

44 MPUMALANGA BETHAL KRIEL RECYCLED / BSM-FOAM (JUNE 2005)

45 BLEEDING : SUMMER 2005 / 6 HIGH TEMPERATURES / HEAVY LOADS (COAL)

46 BETHAL MIDDELBURG CTB < 12 months after rehab

47 BETHAL MORGENZON G1 / C3 < 12 months after rehab

48 BETHAL KRIEL 7 years later...

49 3km HMA Section (Kriel Town Power Station) (25mm HMA)

50 Philosophical argument? South Africa: KZN DoT (since 1996) Ethekwini Metro (since 1997) Other Provincial Main Roads Specialist laboratory for BSMs

51 ITS (kpa) Dry density (kg/m 3 ) BSM LABORATORIES (PTY) LTD Bitumen Stabilised Materials Testing Laboratories Reg. No. 2009/023623/07 VAT No Westmead Road, WESTMEAD, 3608 KZN, South Africa Telephone No. +27 (0) FAX No. +27 (0) Client: EXAMPLE PROJECT Job Card No 123 Project: A Typical Main Road Date Received 05 January 2011 Sample Number: 1111 Date Tested: 10 January 2011 Sample Delivered By: Contractor Date Reported 14 January 2011 FOAMED BITUMEN MIX DESIGN REPORT - LEVEL 1 MATERIAL TO BE STABILISED Aggregates Bitumen Active Filler Description Pa R Br Qtz Pebbles + Gravel + RA 80/100 Lime Location / Source: km SAPREF Northern Lime MATERIAL TO BE STABILISED Aggregates Bitumen Active Filler Maximum Dry Density (kg/m3) 2075 Optimum moisture content (%): 8.0 Location / Source: km /100 Lime FOAMED BITUMEN STABILISED MATERIAL SPECIMENS Description Pa.R.Br.Qtz. Pebbles + Gravel + RA SAPREF Northern Lime BSM-emulsion Maximum Compactive effort 100mm & dry density BSM-foam : (kg/m3) 2075 Optimum moisture content (%): 8.0 Vibratory Hammer : TG2(2009) Method 8(2) diameter Date moulded 10 January 2011 FOAMED BITUMEN STABILISED MATERIAL SPECIMENS Foamed Bitumen added (%) Compactive effort Mod AASHTO TMH 1 - A7. 150mm diameter Bitumen foaming conditions: Water added (%) 2.3 Temperature ( C) 175 Type and percent filler added (%) 1% Lime 1% Lime 1% Lime 1% Lime Date moulded 21 January 2011 Moulding moisture content (%) Foamed bitumen added (%) 2.2 Bitumen foaming conditions: Water added (%) 2.3 Temperature ( C) 175 TEST RESULTS Active filler added (%) 1% Lime ITS dry (kpa) Average Diameter (mm) Moisture content at break (%) Average Height (mm) Dry Density kg/m Temperature at break (oc) Moulding moisture content (%) Mix Designs / QA / Research ITS wet (kpa) Dry Density kg/m Moisture content at break (%) TEST RESULTS Dry Density kg/m Confining Stress (σ Temperature at break (oc) ) (kpa) Applied Failure Load (kn) Tensile Strength Retained (%) Moisture Content at break (%) TG2 (2009) Material Classification BSM 1 BSM 1 BSM 1 BSM 1 BASED ON ITS DRY AND ITS WET TG2 (2009) Temperature at break ( o C) % Foamed Bitumen vs ITS 420 % Foamed Bitumen vs Dry density CALCULATIONS Applied Failure Stress (kpa) Mass of dead loads (kg) Stress due to dead loads (kpa) Major Principle Stress 2075 (kpa) at failure (σ 1,f ) ITS dry Foamed Bitumen added ITS wet Dry Specimens Foamed Bitumen added Wet specimens BSM LABORATORIES (PTY) LTD Bitumen Stabilised Materials Testing Laboratories Reg. No. 2009/023623/07 VAT No Westmead Road, WESTMEAD, 3608 KZN, South Africa Telephone No. +27 (0) FAX No. +27 (0) Client: EXAMPLE PROJECT Job Card No 123 Project: A Typical Main Road Date Received 05 January 2011 Sample Number: 1111 Date Tested: 21 January 2011 Sample Delivered By: Contractor Date Reported 26 January 2011 FOAMED BITUMEN MIX DESIGN REPORT - LEVEL 3 : TRIAXIAL TESTS > 200 BSM MIX DESIGNS SHEAR PROPERTIES: COHESION (C) (kpa) TG2 (2009) Material Classification: BSM 1 ANGLE OF FRICTION (φ)

52 Philosophical argument? South Africa: KZN DoT (since 1996) Ethekwini Metro (since 1997) Other Provincial Main Roads Specialist BSM laboratory Offshore: North America (Canada, Alaska, USA,etc.) South America (Brazil, Chile, Peru, etc.) Africa (Zambia, Namibia, Kenya, etc.) Asia (Mainly China) Europe (Greece, Italy, Croatia, etc.)

53 KENYA. 100km Rift Valley project (2008) Mau Escarpment 4km steep gradient Hot daytime temperatures 19mm Cape Seal 175mm BSM 1 base 300mm C3 cemented subbase (UCS < 3MPa) 150mm selected subgrade CBR > 15 Subgrade CBR 10

54 Athens Corinth Rehab Project ESALs / year ± vpd 15% heavy heavies / day 8 years : > ESALs (13 ton legal axle load) ADE ± / day ( 4 ESALs / heavy )

55 ALASKA, 2002

56 Stabilised 200mm imported G2 material Foamed bitumen addition: 2.5% No active filler added (cement or lime)

57 Completed BSM base before surfacing (chip seal)

58 BRAZIL HMA BSM-1 50mm 100mm BSM-1 200mm Ayrton Senna Highway AADT > 250,000vpd (15% heavy) (> 15,000 heavies / day in each direction) G2 G6 G7 200mm 200mm

59 AADT > 250,000vpd (15% heavy) (> 15,000 heavies / day in each direction) After 6 months... > 3 x 10 6 ESALs

60 Philosophical argument > km successful projects

61 Based on laboratory data and field observations. < 100 km data set

62 Still need a meeting of the minds... THANK YOU!

The AASHO Road Test site (which eventually became part of I-80) at Ottawa, Illinois, was typical of northern climates (see Table 1).

The AASHO Road Test site (which eventually became part of I-80) at Ottawa, Illinois, was typical of northern climates (see Table 1). Página 1 de 12 AASHO Road Test The AASHO Road Test, a $27 million (1960 dollars) investment and the largest road experiment of its time, was conceived and sponsored by the American Association of State