2015ACEC
HMAUpdate
Kevin Kennedy HMA Operations Engineer
Michigan Department of Transportation2‐5‐15
HotMixAsphalt(HMA)Update
• Acceptance of HMA on Local Agency Projects
• HMA Quality Improvements
• Recycled Tire Rubber Permissive Specification
• Miscellaneous Specification Changes
• HMA Production Manual
• National Peer Review
AcceptanceofHMAonLocalAgencyProjects
• Specification in Approval Process
• Covers Roller Method and Density Testing with Nuclear Gauge
• Revises Tolerance Limits and Penalty Structure for HMA Mixtures
• Strengthens Sampling and Testing Requirements
• Adds Time Frame for Reporting Quality Assurance Test Results
LocalAgency‐ToleranceLimits
Table1–UniformityToleranceLimitsforHMA
Parameter Top and Leveling Course Base Course
Number Description Range 1 (a) Range 2 Range 1 (a) Range 2
1 % Binder Content -0.30 to +0.40 ±0.50 -0.30 to +0.40 ±0.50
2
% P
assi
ng
# 8 and Larger Sieves ±5.0 ±8.0 ±7.0 ±9.0
# 30 Sieve ±4.0 ±6.0 ±6.0 ±9.0
# 200 Sieve ±1.0 ±2.0 ±2.0 ±3.0
3 Crushed Particle Content (b) Below 10% Below 15% Below 10% Below 15%
a. This range allows for normal mixture and testing variations. The mixture must be proportioned to test as closely as possible tothe Job-Mix-Formula.
b. Deviation from Job-Mix-Formula.
AcceptanceofHMAonLocalAgencyProjectsSamplingandTesting
Requirements• All persons performing testing must be Bituminous (Bit) Level One certified or Bit Quality Assurance/Quality Control (QA/QC) Technician certified.
• All laboratories performing local acceptance testing must be qualified laboratories.o Qualified per the HMA Production Manual and participate in the MDOT Round Robin process
o or Laboratory must be AASHTO Materials Reference Laboratory (AMRL) accredited for AASHTO T 30 or T 27, and AASHTO T 164 or T 308.
• Contractor Laboratories:o Non‐NHS: Allowedo NHS: Not Allowed
AcceptanceofHMAonLocalAgencyProjectsSamplingandTestingRequirements
• Qualified Samplers Required o Qualifying of Samplers to be handled by Ferris State Universityo MTM 313 (Sampling HMA Paving Mixtures) o MTM 324 (Sampling HMA Paving Mixtures Behind the Paver)
• Minimum – Obtain and test two samples per day (no longer testing at frequency determined by engineer)
• Quality Assurance Test Results – Time Requiremento 7 days – projects more than 5000 tonso 14 days – projects less than 5000 tons
AcceptanceofHMAonLocalAgencyProjectsPenaltyStructure
Table 3: Penalty Per Parameter
Out of specification‐ 2 consecutive tests outside of range 1 or range 2
Mixture Parameter out-of-specification
per Acceptance Tests
Mixture Parameter out-of-specification per Dispute
Resolution Test Lab Price Adjustment per Parameter
NO N/A None
YES
NO None
YES
Outside Range 1 but not Range 2: decrease by 10%
Outside Range 2: decrease by 25%
AcceptanceofHMAonLocalAgencyProjectsDensityTesting
• Two Optionso Direct Density Method Nuclear density gauge 92‐98 percent of density control target (Gmm from JMF)
o Roller Method Added table for Minimum Number of Rollers Recommended Based on Placement Rate
Added table for Density Frequency Curve Development.
• Timingo During paving operationso Prior to traffic staging changeso Prior to subsequent lifts and opening to traffic
AcceptanceofHMAonLocalAgencyProjectsAdditionalSignificantChanges
• Regress air voids in production to 3.5%
• Dispute Processo Range 1‐ Independent Laboratoryo Range 2‐ Construction Field Services HMA laboratory (MDOT Central Laboratory)
AcceptanceofHMAonLocalAgencyProjectsFutureChanges
• Move towards volumetric testing
• Air Voids, VMA, ??
• Doesn’t Necessarily Mean SuperPave
• Sampling Behind the Paver/ Mini‐Stockpile
HMAQualityImprovements
• Regress Mixes to 3% Air Voids
• Requiring Fine‐Graded or Gap‐Graded for Top Courses
• Ride Quality Incentive
Quality–RegressHighVolumeMixes• Regress Mixes to 3% Air Voids in Production for E10, E30 and E50 Mixes
• Effective October Letting
Table 3‐ For mixtures meeting the definition for top and leveling courses: Mixtures must be designed to 96.0% of Maximum Specific Gravity (%Gmm) at the design number of gyrations, (Nd). During field production Percent of Maximum Specific Gravity (%Gmm) at the design number of gyrations, (Nd) will be increased to 97.0% for E10, E30, & E50 mixes. For all other mixes, Percent of Maximum Specific Gravity (%Gmm) at the design number of gyrations, (Nd) will be increased to 96.5% during field production.
Quality‐RegressAllMixes
• Regress Mixes to 3% Air Voids in Production For All Mixes
• Effective March Letting
Unless noted otherwise on the plans, all mixtures must be designed to 96.0% of Maximum Specific Gravity (%Gmm) at the design number of gyrations, (Nd). During field production Percent of Maximum Specific Gravity (%Gmm) at the design number of gyrations, (Nd) will be increased to 97.0%.
Quality‐RegressAllMixes
• Additional Changes
• Changing the upper air voids limit on single test acceptance (changed to 2.0 from 2.5)
• Changing suspension limits in Table 4 for binder content (changed from 1.00 to 0.75)
• Changing the sublot Rejectable Quality Limits (RQL) for air voids (changed to +2, ‐1.5 from +2,‐2)
• Adding removal limits for lots on one course overlays (501V)
Quality‐RegressAllMixesTable4
Col. I ‐ Quality Characteristic
Col. II ‐ QC Action Limits (a)
Col. III ‐ QC Suspension Limits (b)
Col. IV ‐ QA Suspension LimitsForm 1165 (a)
Col. V ‐ Sublot RQL Form 1165 (c) Col. VI ‐ Lot AQL (d)
Col. VII ‐ Lot RQL (d)
Aggregate Gradation (optional)
Aggregate Moisture
Binder Content ± 0.50 JMF ± 0.75 JMFPWLBINDER ≥ 90 For
any lotPWLBINDER < 50 For
any lot
Combined Mixture Gradation
Defined in the HMA‐QC Plan Refer to Table 2
Maximum Theoretical Specific Gravity ± 0.013 JMF ± 0.020 JMF
Bulk Specific Gravity
Volumetrics: Air VoidsDefined In the HMA‐
QC Plan ± 1.00 of Target Air Voids+ 2.00, ‐1.50 of Target
Air voidsPWLAV ≥ 90 For any
lotPWLAV < 50 For any
lot
Volumetrics: VMADefined In the HMA‐
QC Plan± 1.00 of VMA Targets in
Table 3
± 2.00 of VMA Targets inTable 3
PWLVMA ≥ 90 For any lot
PWLVMA < 50 For any lot
Fines to Effective Binder
Defined In the HMA‐QC Plan 0.60 – 1.40 (a) 0.60 – 1.40
In‐Place DensityDefined in the HMA‐
QC PlanDefined in the HMA‐QC
PlanAverage Sublot Value
< 90.00%PWLD ≥ 90 For any
lotPWLD < 50 For any
lot
a. Limits apply to two consecutive QC or QA tests.b. Limits apply to single QC tests.c. Specified. Limits apply to a single QA sublot Air Void or VMA test or on the sublot average In‐Place Density.d. Specified. Limits apply on a lot‐by‐lot basis. Based on QA results for the lot.
Quality–FineGraded/GapGradedonTopCourse
• Changed Gradation to Eliminate Coarse Graded Mixes
• Eliminated Restricted Zone
• FUSP 902E
• Effective January Letting
• Revises Table 902‐5 and 902‐6
Quality– FineGraded/GapGradedonTopCourse
Revised Table 902‐5Superpave Final Aggregate Blend Gradation Requirements
Standard Sieve
Percent Passing Criteria (control points)Mixture Number
5 43 Leveling Course
3 Base Course2 LVSP (a)
1½ in — — — — 100 —1 in — — 100 100 90–100 —¾ in — 100 90–100 90–100 ≤90 100½ in 100 90–100 ≤90 ≤90 — 75–95
⅜ in 90–100 ≤90 — — — 60–90No. 4 ≤90 — — — — 45–80No. 8 47‐75 39‐69 35–60 23–49 19–45 30–65No. 16 — — — — — 20–50No. 30 — — — — — 15–40No. 50 — — — — — 10–25No. 100 — — — — — 5–15No. 200 2.0–10.0 2.0–10.0 2.0–8.0 2.0–8.0 1.0–7.0 3–6
a. For LVSP, less than 50 percent of the material passing the No. 4 sieve may pass the No. 30 sieve.
Quality–FineGraded/GapGradedonTopCourse
Revised Table 902-6Superpave Final Aggregate Blend Physical Requirements
Est. Traffic(million ESAL)
MixType
Percent Crushed Minimum Criteria
Fine Aggregate Angularity Minimum
Criteria% Sand EquivalentMinimum Criteria
Los Angeles Abrasion
% Loss Minimum Criteria
% Soft ParticlesMaximum Criteria
(a)
% Flat and Elongated Particles
Maximum Criteria (b)
Top & Leveling Courses
BaseCourse
Top & Leveling Courses
BaseCourse
Top & LevelingCourses
BaseCourse
Top & LevelingCourses
BaseCourse
Top & LevelingCourses
Base Course
Top & LevelingCourses
BaseCourse
< 0.3 LVSP 55/— — — — 40 40 45 45 10 10 — —
< 0.3 E03 55/— — — — 40 40 45 45 10 10 — —
>0.3 -<1.0 E1 65/— — 40 — 40 40 40 45 10 10 — —
>1.0 - < 3 E3 75/— 50/— 43 40 40 40 35 40 5 5 10 10
>3 - <10 E10 85/80 60/— 45 40 45 45 35 40 5 5 10 10
>10 - <30 E30 95/90 80/75 45 40 45 45 35 35 3 4.5 10 10
>30 -<100 E50 100/100 95/90 45 45 50 50 35 35 3 4.5 10 10
(a) Soft particles maximum is the sum of the shale, siltstone, ochre, coal, clay-ironstone and particles that are structurally weak or are non-durable in service.(b) Maximum by weight with a 1 to 5 aspect ratio.
Note: “85/80” denotes that 85 percent of the coarse aggregate has one fractured face and 80 percent has at least two fractured faces.
Quality–RideQualityIncentive
• Specification in Approval Process
• Incentive Starts at IRI of 45
• Increases to $.50 per square yard at IRI of 25
• Applies to High Speed Roads (50 MPH)
• Class I and Class II Roads per Ride Quality Specification
RecycledTireRubber
• Grand Region Pilot Project – 2013M‐57 from East of Northland Drive to West of Morgan Mills Avenue Crumb rubber portion approximately 3.2 miles on M‐57 between Wabasis Road and Morgan MillsAllowed Wet Process or Terminal Blend (contractor’s option)Three binders (64‐22, 70‐22P, 70‐22 crumb rubber modified)6,007 tons HMA 5E3 Crumb Rubber ModifiedBidsLow Bidder‐ $79.45 vs $85.832nd Bidder‐ $71.15 vs $102.97
MDOTPilotProject
RecycledTireRubber
• HMA Tech Committee Directed to Develop Permissive Specification
o Originally‐ specification to mirror pilot project
o Concern over reports of poor performance (Waverly Road, Haslett Road, various Saginaw County projects)
o PG Binder performance tests have been modified or waived
o HMA Technical Committee believes revised tests do not accurately predict performance
o No deviations to acceptance test methods/procedures allowed.
WaverlyRoad
2011 Construction County Road (Photo taken in 2013)
MiscellaneousSpecificationChanges• FUSP 501G (RAP/RAS)‐ Added language referring to production manual for blending charts:• When incorporating RAS the asphalt binder grade will be selected using a blending chart for high and low temperatures.
• The Contractor must supply the blending chart used in determining the binder selection according to AASHTO M 323 and the HMA Production Manual.
• FUSP 501L (Temp Pavement) ‐ Added language clarifying removal of temporary pavement is not part of temporary pavement pay item
MiscellaneousSpecificationChanges• Gap Graded SuperPave‐ New specification for ½” nominal mix and 3/8” nominal mix
• FUSP 504C (HMA ultra‐thin overlay)‐ New specification , no longer Marshall mix. Includes mix design submittal requirements
• HMA Binders‐ Changes coming to Price Adjustment and Certification Procedures
HMAProductionManual• Bureau of Highway Instructional Memorandum 14‐12
o Includes blending chart instructions for RAP/RAS.
o RAP now part of mix design submittal.
o Section 4 was removed from the MDOT HMA Production Manual and added to Section 5.03.01 of the MDOT Materials Quality Assurance Procedures Manual (MDOT MQAPM).
NationalPeerReview• NCAT/NAPA/FHWA
Starting in Spring/Early Summer
Best Practiceso Construction (Tack Coat Application, Joint Construction, Minimizing Segregation)
o Mix Design
o RAP/RAS
o Local Agency Acceptance
GoodGovernmentInAction(GGIA)
• Good Government In Action
o Adoption of methods to make strategically important changes
o Focus on closing performance gaps for anything strategically important
o Customer satisfaction is the primary goal for 2013 & 2014
• Hot Mix Asphalt (HMA) Operations Wildly Important Goal (WIG)
o 2013 ‐ Focus on dispute resolution turn around time
o 2014 – Focus on binder sampling and testing