Advances in Pavement Design, Construction, Preservation, and Assessment

Transcription

1 Advances in Pavement Design, Construction, Preservation, and Assessment ASCE Bituminous Materials Committee Jenny Liu, University of Alaska Fairbanks Louay Mohammad, Louisiana State University Victor (Lee) Gallivan, Gallivan Consulting Inc. Baoshan Huang, University of Tennessee Knoxville March 10, 2016

2 Outline Development and Implementation of Balanced Asphalt Mixture Design Advances in Intelligent Compaction Using Performance Specifications Pre-cut Technique in AC Pavements for Pavement Preservation Optimization of Pavement Preventive Maintenance in Tennessee 2

3 Development and Implementation of Balanced Asphalt Mixture Design Louay N. Mohammad Irma Louise Rush Stewart Distinguished Professor Department of Civil and Environmental Engineering Louisiana Transportation Research Center Louisiana State University

4 My Story Background Asphalt Mixture Design Volumetrics Concerns Selection of Performance Test Simplicity Laboratory-to-field correlations Criteria Sensitivity to mix composition Summary

5 Background Practice of including RAP and/or Recycled Asphalt Shingles (RAS) in new asphalt mixtures has increased in recent years economic and environmental benefits RAP has been widely used Wearing Course: 15% Binder Course: 20% Base Course: 30% RAS has emerged as a material of interest to the paving community RAP and/or RAS are valuable components in asphalt mixtures With increased demand and limited supply of aggregate and binder Concerns Hardened and oxidized asphalt binders Causing premature cracking in pavements Asphalt binder 8 to 30% Mineral matter 40 to 60% Fibers 8 to 12%

6 Typical Asphalt Mixture Design Volumetrics Voids in the Total Mix, VTM Voids in the Mineral Aggregate, VMA Voids Filled with Asphalt, VFA Densification Stages during lab compaction process Total Volume VOLUME air asphal t aggrega te aggregate MASS Total Mass

7 Asphalt Mixture Design: Concern Optimum asphalt cement content Quantity NOT QUALITY RAP and/or RAS VOLUME air MASS Total Volume asphalt aggregate aggregate Total Mass

8 Selection of Mechanical Tests Laboratory Tests Pavement Performance High Temperature Permanent deformation Intermediate Temperature Fracture/Fatigue Low Temperature Low temp cracking Features to be considered Measure/relate to fundamental properties Simple, repeatable, easily-calibrated, quick, not requiring highly-trained personnel, Can utilize low-cost equipment. Sensitive to subtle changes in mixture properties

9 Louisiana Balanced Asphalt Mixture Design High temperature Performance Loaded Wheel Tracking Test AASHTO T-324 Rutting Intermediate temperature Performance Semi Circular Bend Test Cracking LADOTD TR 330 Low temperature performance TSRST

10 LWT Test at High Temperature Test simplicity technician training requirements» Minimal» Several labs (state DOTs, Univ., testing labs) time for preparing samples» Compact, Cut, and preform volumetric measurements» 1 day for the set (4 specimens) testing specimens» 1 day for the set (2 samples = 4 specimens) analyzing data» Spreadsheet: 30 minutes

11 SCB test at Intermediate Temperature Test simplicity technician training requirements» Minimal» Several labs (state DOTs, Univ., testing labs) time for preparing samples» Compact, Cut, and Notch, preform volumetric measurements» 1 day for the set (12 test specimens) testing specimens» 1-2 hours for the set (12 test specimens) analyzing data» Spreadsheet with cut/paste: 15 minutes

12 SCB test at Intermediate Temperature Laboratory-to-field correlations Ten field project Projects in service for 3 10 years LADOTD PMS Cracking Index Y = 100 ( X) -170 ) r 2 : Laboratory Measured Jc, kj/mm AAPT: Development Of Performance Based Specifications For Louisiana Asphalt Mixtures

13 SCB test at Intermediate Temperature Test Criteria High Traffic PMS Trigger LADOTD PMS Cracking Index Low Traffic PMS Trigger Y = 100 ( X) -170 ) r 2 : Laboratory Measured Jc, kj/mm

14 Test Sensitivity to Mixture Composition and Design Parameters Binder type and content, Air voids, RAP and/or RAS, temperature, etc

15 LWT Test Results C, Wet SBS, CRM, RAP Rut Depth, 20K passes, mm CO 70CO-M 76CO-M 76CRM 76RAP15 Binder Type 2011 AAPT: Laboratory Evaluation of Asphalt Mixtures Containing Sustainable Technolo

16 Semi-Circular Bend Test Results, 25 C SBS, CRM Jc, Kj/m CO 70CO-M 76CO-M 76CRM Binder Type 2011 AAPT: Laboratory Evaluation of Asphalt Mixtures Containing Sustainable Technolo

17 Louisiana DOTD Proposed Specification Research projects to create new specification parameters LTRC Project 11-3b LTRC Project 10-4b

18 2013 Proposed Specification LA 519 LA 113 LA 93 US 80 LA 16 Property 2006 Specificatio ns Ndesign, Gyrations Minimum 2013 Proposed Specifications a VMA, % VFA, % Air Voids, % LA TRB: Balanced Asphalt Mixture Design through Specification Modification: Louisiana s Expe

19 LWT Test Results, 50 C 20 PG PG 70-22M PG 76-22M PG 82-22CRM Rut Depth, mm Mixture Number

20 LWT Test Results, 50 C 20 PG PG 70-22M PG 76-22M PG 82-22CRM Rut Depth, mm Mixture Number

21 SCB test Results, 25 C 1.5 PG PG 70-22M PG 76-22M PG 82-22CRM Jc, KJ/m Mixture Number

22 SCB test Results, 25 C PG PG 70-22M PG 76-22M PG 82-22CRM 1.5 Jc, KJ/m Mixture Number

23 LWT Test Results, 50 C 20.0 Rut Depth, 20K passes, mm PG PG M Binder Type PG M PG 82-22rm 19-mm LS

24 Semi-Circular Bend Test Results, 25 C Jc, Kj/m PG PG M PG M Binder Type 19-mm LS

25 Implementation Louisiana DOTD SCB, min, Jc, kj/m 25⁰ C, Aged All mix design level 1 must meet minimum 0.5 Jc, All mix design level 2 must meet minimum 0.6 Jc.

26 Summary Utilize laboratory SGC specimens or field cores Specimen preparation and test set up are simple Quick, not requiring highly-trained personnel Can utilize low-cost equipment Many research publications document the test is sensitive to subtle changes in mixture properties different binder types RAP and/or RAS CRM Test has been implemented by Louisiana DOTD Test has a failure criteria Good correlation to field cracking Stress field resembles pure tensile conditions

27 T H A N K Y O U

28 Advances in Intelligent Compaction Using Performance Specifications Victor (Lee) Gallivan, P.E.

29 Today s Agenda Overview of Intelligent Compaction Technology Where to go for Supporting Information Advancing Performance Specifications for IC - Performance Specifications for Rapid Renewal (R07)

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31 IC Usage Trends The number of projects nationwide which include the use of IC has been increasing 2012 less than 20 projects 2013 approximately 50 projects 2014 projected 150 projects >300 Projects Reasons for the increase: Improvement and availability of IC technology EDC 2 33 states committed to implement IC in the next two years 31

32 ----Definition---- What is Intelligence? Oxford Dictionary: able to vary behavior in response to varying situations and requirements Ability to: Collect information Analyze information Make an appropriate decision Execute the decision TIMES A MINUTE

33 Why Intelligent Compaction? Roller Passes Shoulder (Supported) Paving Direction Longitudinal Joint Courtesy Sakai America 33

34 Global Positioning System GPS emperature Sensors Courtesy of Bomag

35 Minimum requirements of what IC rollers need to have to be IC Vibratory Roller; Real time Kinematics (RTK) GPS system or VRS for roller positioning measurement computer systems; Integrated measurement computer systems to collect & analyze roller and pavement response information; Accelerometers mounted in or about the drum to monitor applied compaction efforts; Temperature instrumentation (HMA) GPS based documentation system

36 Bomag HAMM-Wirtgen Asphalt Caterpillar Sakai

37 Ammann-Case Caterpillar HAMM-Wirtgen Bomag Soils and Dynapac Subbase Sakai

38 IC 100% Coverage ICMV Map Display Documentation of Evib and roller position

39 Reflection of hard spots on the HMA layer HMA Map HMA non-wearing course layer map a = 0.6 mm, f = 3000 vpm Subbase Map Class 5 aggregate subbase layer map, a = 0.6 mm, f = 2500 vpm CCV HMA (a = 0.6 mm, f = 3000) y = 2.45 ln(x) R 2 = CCV Subbase (a = 0.6 mm, f = 2500) Reflection of hard spots on the HMA layer Reflection of soft spots on the HMA layer 39 MN ICPF Project

40 What is 100% Coverage? Traditional methods only obtain data on a single spot that represents a large area is test result representative? IC provides data for the entire area being compacted ICMV, temperature, pass count Color coded mapping of 100% of area provides permanent records

41 Overall Findings and Use At this time, IC is not ready for use as a Quality Assurance (acceptance) tool Consistently reliable correlation between ICMV and in situ (HMA) density readings have not been established On many projects, there has been a relationship between ICMV and density/compaction IC can be used as a Quality Control (QC) tool Contractors can use IC capabilities to improve their compaction process 41

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43 IC Measurement Value (ICMV) ICMV is a generic term used to describe all suppliers measurement value IC suppliers have various stiffness (or measurement) values Bomag E vib (MN/m²) Caterpillar CMV Hamm/Wirtgen HMV Sakai - CCV VETA (Software)

44 VETA (Veh-ta) Data Management Tool Geospatial Analysis Software for Intelligent Compaction Import data from various IC suppliers Perform viewing, editing/layering, point tests, and Data analysis. 44

45 QUALITY IS NOT ALWAYS EASY TO SEE UNLESS IT IS DEFINED 45

46 Improved Rolling Patterns hence Improved Compaction and Performance Before After Indiana ICPF Project Sakai IC roller 46

47 Overall Benefits of Intelligent Compaction Improve density.better performance Improve efficiency.cost savings Increase information better QC/QA

48 Guide IC Specs FHWA Soils/Asphalt IC AASHTO PP81-14 Generic IC Specifications are available for free download From

49 Alabama Vermont (FDR) Missouri Pennsylvania(P3) Maine S2-R07-RR-2 S2-R07-RR-1 S2-R07-RR-3

50 For More Info on IC Website IntelligentCompaction.com Phone (512)

51 Victor (Lee) Gallivan, P.E. Gallivan Consulting, Inc. Asphalt Pavement Engineer CL: Questions? Discussions?

52 Sitka Alaska Airport Courtesy of Bruce Christianson

53 Pre-cut Technique in AC Pavements for Pavement Preservation Jenny Liu, Ph.D., P.E., Professor Center for Environmentally Sustainable Transportation in Cold Climates (CESTiCC) University of Alaska Fairbanks

54 Introduction Pavement preservation treatments are widely used in cold regions. Five preservation treatments have been used to date in Alaska: thin HMA overlays, chip seals, slurry surfacing, crack sealing, and pre-saw cut joints Thermal cracks are perhaps the most noticeable form of crackrelated damage in asphalt pavement in cold climates Current practices to address thermal cracking Crack sealing Better mix designs Different asphalts Precutting 54

55 Precut Technique Not a new technique, has been used in concrete pavement for years Control joints are established to provide stress relief The precut cracks show better appearance than natural cracks Minnesota has experienced success with presawn thermal cracks since first testing in 1969 Author s subjective feelings vehicle ride smoothness has been preserved due to: Less spalling of natural cracks Less accumulated maintenance materials 55

56 Pre-saw Cut Joints Alaska experimental feature Phillips Field Road in 1984 Made on a new section of HMA with approximately 50 ft spacing without sealing pre-cut joints. In over a decade there is no substantial deterioration to warrant any rehabilitation work. There are not any substantial cracks in between most pre-cut joints. Pre-cuts initiate stress concentrations at the cut locations while relieving stresses at other locations in the pavement. Less accumulated maintenance materials 56

57 Field Evaluation Test sections at Richardson Hwy, Moose Creek (20 miles SE of Fairbanks), built in sections, all on Pavement Structure I Precut depth: 0.5, 1.0 and 1.5 inches Precut spacing: 25 and 40 feet Surveyed after 1 year (2013) and 2 years (2014) Test sections at Parks Highway, Healy, 100 miles SW of Fairbanks, built in sections, on Pavement Structure II-V Precut depth: 0.625, 1.25, and 2 inches Precut spacing: 25 and 35 feet Surveyed after 1 year (2015) 57

58 General Precut Installation Laying out Precuts Thin Saw Used for Precuts 12 Diameter x 1/8 Thick Blade Precutting Operation recutting Operation, Distant View Measuring Precut Depth Measuring Precut Width 58

59 Types of Cracks Inspected Precut Crack Natural Transverse Thermal Crack Natural transverse crack Precut non-active crack Precut active crack precut cracks with partial capture of natural cracks 59

60 Moose Creek Survey Results Survey after 1 year Survey after 2 years 60

61 Healy Survey Results Survey after 1 year Survey after 1 years 61

62 FEM Simulation Schematic Plot of Simulation Sections AC ATB Base Subbase Subgrade Thickness (m) E ( 10 3 MPa) Poisson s Ratio Density ( 10 3 kg/m 3 ) Thermal Conductivity ( 10 6 J/day m C) Specific Heat ( 10 3 J/kg C) Coefficient of Thermal Expansion ( 10-6 / C) Simulation Inputs FEM model with mesh grid The intention of precut is to proposedly create high stress concentration at the pre-cut tip (location) and reduce stress anywhere else. For this simulation, a possible thermal crack was set to be 0.04 (1 mm) wide and 0.2 (5 mm) deep as the reference. And the saw cut was set to be 0.12 (3 mm) wide with various cutting depths. 62

63 63 25 spacing with 1.5 saw cutting depth Simulation Results 25 spacing with 0.5 saw cutting depth Control section without saw cut, but with pre-designed natural thermal crack 25 spacing with 1.0 saw cutting depth

64 Summary Precutting treatment appears promising to control thermal cracks. Shorter precut spacing and deeper precut depth look promising in crack control according to preliminary results. These findings were based on preliminary results from relatively short time periods. Continuing evaluation and monitoring of test sections and cost effectiveness analysis are needed to recommend an effective design methodology and construction practice for Alaska and cold areas of other northern states. 64

65 Optimization of Pavement Preventive Maintenance in Tennessee Baoshan Huang, Ph.D., P.E. Professor, Dept. of Civil and Environmental Engineering University of Tennessee at Knoxville

66 Highway Pavement Management Application Established in 1980s 1,104 miles interstate and 14,359 state route. Budgets Pavement Management System Cost-effective strategies Pavement Condition Evaluation Pavement Performance Curves Do-nothing performance Treatment performance

67 Pavement Maintenance Optimization 3792 maintenance records, and detailed treatment information: As an Information System Treatment performance models Pavement performance data of 1104 HMA maintenance projects (2742 sections). Cost-effectiveness analysis Calibrate treatment performance models PSI Age (year)

68 Performance of Pavement Treatments Pavement Performance Indicators PSI Cracking TDOT HPMA LTPP Database Data Sources Overlay thickness Milling Influencing factors Material Pre-treatment condition Traffic level Environment Analysis Methods Multiple Linear Regression Survival Analysis Log-linear (Poisson) Regression

69 Cost-effectiveness Analysis PSI Jump Effectiveness Treatment service life Effectiveness/Cost-effectiveness = f (Treatments, Pre-PSI, AADT, overlay thickness, milling depth, )

70 Cost-effectiveness Analysis Thick overlay and milling depth improve the long term benefit. Effectiveness and cost-effectiveness can be optimized at a specific age of maintenance treatment, depending on the rate of PSI deterioration. Thicker overlay and deep milling reduced the cost-effectiveness. 3 Benefit/ cost ± Overlay Mill_depth k1 b1 thickness (in.) (in.)

71 Calibration of Treatment Performance Models PSI Pre-treat curve Post-treat curve Predictors: Pre-treatment PSI AADT 0 Overlay thickness Milling depth Age (year) Responses: Slopes of treatment performance curves Intercepts of treatment performance curves

72 Calibration of Treatment Performance Models Slope of PSI curve = f (Thickness, Mill depth, Pre-PSI, AADT) Post-treatment PSI : 3.8~4.2 Combination of PSI curves of different treatments at different classes 9*3*3=81 models 5 4 PSI Age (year) O1, pre-psi level = 3, AADT level = 1 PSI Age (year) Default in HPMA

73 Calibration of Treatment Performance Models Specific Road section Current PSI/PDI/PQI condition Historical performance data Decision tree Do-nothing performance Treatment performance Treatment candidates Treatment performance models Cost-effectiveness analysis (Compare PQI areas) Optimized treatment and time

74 Application of the models in network level analysis Unlimited budget, PQI > million/year 20 million/year 10 million/year To eliminate poor sections, must 9 million/year 0 million/year

75 Application of the models in network level analysis Annual cost (million $) Annual cost (million $) Annual cost (million $) Year Year Year Unlimited budget, PQI > million/year 20 million/year Annual cost (million $) Annual cost (million $) Maintenance needs are different at different years Year Year 10 million/year 9 million/year

76 Application of the models in network level analysis Budget level must 10 million/year Higher budget level can satisfy high needs at some years, therefore the most cost-effective strategy can be found by setting a sufficient high budget level. 200 Total costs Average PQI Total costs PQI/cost 50 Total costs (Million $) Average PQI Total costs (Million $) PQI/cost (1/billion $) 0 Unlimited Budget level (Million $) 0 0 Unlimited Budget level (Million $) 0

77 Thanks!