Performance Guidelines for Selection of Hot-Poured Bituminous Crack Sealant

Transcription

1 Performance Guidelines for Selection of Hot-Poured Bituminous Crack Sealant Northeast Pavement Preservation Meeting Warwick, Rhode Island, 2007 Advanced Transportation Research and Engineering Laboratory University of Illinois at Urbana-Champaign Imad L. Al-Qadi J-F Masson S-H Sam Yang Eli Fini

2 What is Crack Sealant? Blends of bitumen and styrene-butadiene copolymer (SB, SBS) recycled rubber additives inorganic filler bonding agent A B M H E 500 μm 500 μm 500 μ m 500 μm 500 μ

3 Crack Sealing Crack sealing/ filling is the most widely used maintenance activity of in-service pavements Inexpensive, quick, and a well-proven technique to delay pavement deterioration Reduce water penetration Maintain pavement structural capacity Improves road rideability Extend pavement service life (3 to 5 years)

4 Field Performance of Crack Sealant Installation related parameters (QC/QA, crack cleaning and preparation, etc.) Sealant related parameters (viscosity, softness, bond strength, compatibility, etc.)

5 Sealant Failure Modes Tracking: sealant is smeared on the pavement due to passing traffic Adhesive failure: loss of bonding between sealant material and its substrate Cohesive failure: failure within sealant material Intrusive failure: foreign objectives intrude into sealants

6 Available Specifications Sealant Property Test Method ASTM Spec. Application Characteristics Viscosity (binder) D4402 Adhesion Bond Test D5329 Asphalt Compatibility D5329 Extensibility Elongation (rubber) D412 Ductility (binder) D113 Durability Track Abrasion (slurry) D3910 Flexibility Flexibility D5329 Cone Penetration D5329 Tracking Flow D5329 Softening Point D36

7 Objective Development of performance-based guidelines for the selection hot-poured crack sealant Make use of SuperPave binder-testing equipment Adapting spirit of the binder Performance Grade (PG) specifications

8 Viscosity Test (SC-2) At Installation Temperature

9 Test Development Instrument and Testing Optimization Rigid rod Melting time 20min Spindle size SC-27 Speed 60rpm Waiting time 30s Test variable Viscosity (pa.s) (Pa.s) Temperature VV BB NN ADQQ AE WW Temperature Time (s) (C)

10 ZZ Apparent Viscosity Threshold BB PP WW UU EE AE AD MM VV QQ NN YY DD AB Apparent Viscosity (Pa.s) Sealant

11 Vacuum Oven Aging (SC-3) Simulate Crack Sealant Weathering in Kettle & Field

12 Test Development Microwave aging Small-kettle aging and pressure aging Small-kettle aging, pressure aging and vacuum oven aging Pressure aging Vacuum oven aging

13 Test Development Method GPC FTIR TGA DSR Output Separation of bitumen and polymer Fingerprint of composition Weight loss upon heating Stiffness, relaxation

14 Test Procedure 35g in each pan Vacuum oven at 30 Hg and 115 C for 16hr Shelves spacing designed to allow uniform temperature profile

15 Test Verification 1.E+07 1.E+06 Viscosity, Pa.s 1.E+05 1.E+04 virgin 1 year 9 year 16h 24h 40h 64h 1.E Temperature, C

16 Dynamic Shear Rheometer Test (SC-4) Intermediate Temperature for Tracking Resistance

17 Test Development Taber Abraser to simulate field failure Correlate tracking flow as measured with DSR Shear stress is applied for 2s then removed to allow recovery for 18s 8 levels of stresses were applied Strain Year 1 Year 4 Stress = 20Pa No stress: recovery permanent deformation Time

18 Test Parameter Ostwald-DeWaele power-law P ) Stress, Pa σ = C( γ& γ& C: flow coefficient P: shear thinning exponent Shear rate, 1/s γ& 46C 52C 58C 64C 70C 76C 82C

19 Selection Criteria Flow coefficient (C)/ Pa.s A no tracking 1 sample tracks 2 samples track B 0 C0 97% D E100% Shear thinning exponent (P)

20 Bending Beam Rheometer (SC-5) Low Temperature Flexural Properties

21 Test Development Deflection of the sealant bean is above the limit of the current BBR device Doubling the beam thickness Modifying BBR device to support both binder and sealant beams 7 Deflection (mm) Deflection (mm) Deflection Load Load Crack 160 Sealant Specimen Time Time (s) Load (mn) Deflection Standard Binder Specimen Load (mn) 6.35mm 12.7mm

22 Test Parameter 240s S(t) = Average creep rate ε( t) = PL 4bh 3 δ At C (t) Deformation Strain (%) (mm) Deformation Load = (t) R2 = Load (N) Time 400(sec) Time (s)

23 CSBBR Threshold C -4 C C C C C C C C C C C S( C)=85MPa 5 0 QQ EE ZZ YY AB VV UU DD AE MM WW NN AD PP BB Average Stiffness Rate (MPa) of Creep Sealant

24 CSDTT Test (SC-5) Low Temperature Extendibility

25 Test Development Crack movement in the field Simulates sealant extension in the field Modification for existing testing Extension of SuperPave TM specimen: A 33%90 + % Utilize FE tool to select appropriate specimen Dim. Select appropriate loading rate B 6%/min Type A and B Max Crack Studies Disp. Rate, Strain Rate, (%) Smith mm/min & Romine, 1993 mm/min18 Linde, % 63 Cook et 2 al., % +90 Masson 0.2& Lacasse, % 16 Min Crack CFast Type Move. C Slow Move. Disp. (%) Rate, (mm/min) Strain (mm/min) Rate, 2.5 mm/min 5x10-3 mm/min 2.77x10-4 N/A 12 8x % 5x N/A 6.0% N/A N/A 0.6% N/A

26 Test Parameters Extendibility (l) Effective gauge length (L eff =20mm) λ = ΔL L eff The extendibility criterion is suggested based on various climatic conditions T ( C) -4 λ(%) 10% 25% 40% 55% 70% 85% 85+

27 CSDT Threshold Extendibility(%) C Grade + C Grade + C Grade C Grade C Grade C Grade C Grade C Grade C Grade C C C DDQQ AE EE MM ZZ WW NNYY AD AB PP VV BB Sealant Sealant

28 Adhesion Test (SC-7) For Low Temperature Bonding

29 Test Development Surface Energy Method (Work of Adhesion) A compatibility test for sealant producers Direct Bond Method A quality control test for DOT Blister Test Method Fundamental test for advanced research

30 Substrate Selection Coefficient of Thermal Expansion Surface Energy Surface Roughness Coeff. of Thermal Exp., Material Limestone>Sandstone>Quartzite>Granite> Steel>Aluminum Pore Size cm/cm/ C x 10 6 Sandstone>Quartzite>Aluminum Surface Energy, mj/m 2 Aluminum oxide Soda Lime Glass 8 72 Polycarbonate Stainless Steel Granite Limestone Quartzite Aluminum was conservatively selected as substrate Sandstone Basalt

31 1 st Level Adhesion Test: Work of Adhesion Work of Adhesion (mj/m 2 ) Limestone Quartzite Granite Aluminum W a = total s γ ( 1+ cosθ ) UU BB AE PP AD WW MM

32 2 nd Level Adhesion Test: Direct Bond Test (CS-7) Fixture designed to be used in the DT device Two aluminum half-cylinders Diameter: 25mm Sealant thickness: 10mm Simulates sealant installation Simulates crack expansion Displacement rate: 0.05mm/s Specific failure location

33 Test Parameter P max De-bond Energy P max Energy Load (N) Displacement (mm)

34 Bonding Threshold P max (N) A B PP LL 0 Non-aged Ovenaged Kettle aged Less than 3yr More than 3yr Energy (J/m 2 ) A B PP LL 0 Non-aged Ovenaged Kettle aged Less than 3yr More than 3yr

35 3 rd Level Adhesion Test: Blister Test IFE E (t). =. P(t) CPdC d(t) IFEprop ini = = AVG[IFE(t)] IFEini. p( t) d( t) E(t ) E( t) IFEprop.

36 Test Parameter IFE ini (J/m 2 ) IFE (J/m 2 ) EE DD UU AB QQ Temperature ( C) IFE ini (J/m 2 ) IFE (J/m 2 ) AD BB PP NN LL AE MM 0 Temperature ( C)

37 SG-46 SG-52 SG-58 SG-64 SG-70 SG-76 SG-82 Crack Sealant Performance Grade Installation Temperature Apparent Viscosity, SC-2 Max. Viscosity (Pa.s) 3.5 Min. Viscosity (Pa.s) 1 Vacuum Oven Residue (SC-3) Dynamic Shear, SC Min. Flow Coefficient (kpa.s) Min. Shear Thinning Crack Sealant BBR, SC-5 Max. Stiffness (MPa) 25 Min. Avg. Creep Rate Crack Sealant DTT, SC-6 >10 >25 >40 >55 >70 >85 >85 >10 >25 >40 >55 >70 >85 >85 >10 >25 >40 >55 >70 >85 >85 >10 >25 >40 >55 >70 >85 >85 >10 >25 >40 >55 >70 >85 >85 >10 >25 >40 >55 >70 >85 >85 >10 >25 >40 >55 >70 >85 >85 Min. Extendibility (%) Crack Sealant DBT, SC-7 Min. Load (N) 50 Min. Energy (J/m 2 ) 40

38 Outcome of the Study Comprehensive tests based on sealant rheological properties was developed Selection criteria is proposed A significant economic impact on the sealant industry and the pavement preservation program is expected

39 Future Plan Laboratory validation Field validation Monitoring test section for four years Fine tuning thresholds Quantify cost effectiveness of crack sealant

40 Acknowledgements Federal Highway Administration Pool-fund TPF5 (045) The US-Canadian Crack Sealant Consortium Participating US states, Canadian provinces, airport and city agencies, and industry

41 A continuation of this pool-fund study has been decided in the last consortium meeting Virginia will be the lead state Please contact: Kevin McGhee of VTRC ) Imad Al-Qadi Eli Fini and S-H Sam Yang

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