Asphalt Issues AASHTO SCOC Virginia Beach, Va. By Victor (Lee) Gallivan FHWA August 2, 2011
HMA Topics for the Day Reclaimed Asphalt Pavement (RAP) Updated Thin 4.75 mm surface mixture Construction Specifications for IC
Recycled Materials Survey Conducted through AASHTO SOM List Serve. Sent end of December Various questions related to RAP, RAS, RCA. 45 state responses plus West Federal Lands and Ontario. Some data used is from 2007/2008 survey due to lack of responses.
Survey Survey (cont) Main Survey Questions Allowance of recycled materials (RAP, RAS, RCA) per specifications? Contractors actual usage of recycled materials? Special testing/handling procedures? Research needs, major concerns/obstacles for increased usage of recycled materials?
RAP Survey Items of note from survey… RAP Availability – contractor/DOT ownership? WMA - Increased usage during DOT implementation? Stockpiles - Fractionation, captive stockpiles becoming more prevalent?
RAP Survey RAP Survey (cont) Research Needs: Needed dwell time for mixing? Mix performance tests (long-term durability, thermal cracking, f/t resistance). Binders - bumping, blending, stiffness/cracking, interaction with polymers. Determining RAP binder properties. Skid resistance.
Since 2007/2008 Survey… RAP % allowed by percentage has stayed pretty consistent for DOT’s. For RAP utilization by contractors, it appears the 20-30% usage has increased the most with all other percentages staying pretty much the same.
RAS Survey Items of note from survey… Sources – pre/post consumer supply (about 50/50). Special Requirements – gradations, asbestos testing.
RAS Survey RAS Survey (cont) Research Needs % binder contribution Mix performance testing Binder bumping, blending Fatigue and low temperature cracking Use in WMA? Use of rejuvenators Binder impacts
HMA Topics for the Day Reclaimed Asphalt Pavement (RAP) Updated Thin 4.75 mm surface mixture Construction Specifications for IC
Thin Lift 4.75 mm HMA Mix AASHTO M 323 Revisions Gradation Lay thickness Acceptance (no cores)
Intelligent Compaction
FHWA Generic IC Spec Subbase Soils HMA
Soils IC vs. HMA IC Soils IC Moistures Acceptance HMA IC Temperatures Acceptance
Components of Standards 1.Approval of IC Equipment 2.IC Data Requirements 3.Quality Control Plan 4.GPS/Datum Requirements 5.Test Sections and Target Values 6.QC/QA for Production Areas 7.IC Data Submittal 8.Payment and Measurements
1. Approval of IC Equipments Continuous Measurement System RTK GPS Onboard Reporting System
2. IC Data Requirements Compatible with Standardized IC Software (Veda) Headers Manufacturer Machine Type Machine Model Drum Width Drum Diameter UTM Zone….. Data Blocks Date/time stamp Long/Lat Easting/Northing Pass Counts Speed Frequency Amplitude Temperatures IC Measurement Values
IC Analysis with Veda
3. Quality Control Plan Contract-Specific Quality Control Plan (QCP) Signed by Contractors Accepted by DOTs Implementation of QCP QCP Field Manager Quality Control Technician
4. GPS/Datum Requirements Datum Designation/Conversion GPS Checks
5. Test Sections/Target Values Dimension of Test Sections E.g., 75 m X 6 m for soils Evaluation for Each Lift Materials Fixed Settings of IC Compaction Determination of Target Roller Passes and IC-MV
QC Target Values Optimal pass Target ICMV ICMV<5%
QA Target Values ICMV Target ICMV Target % Gmm % Gmm
6. QC/QA for Production Areas Mapping of Existing Support QC for Production Compaction Coverage Percent Requirements Meeting Target Values Acceptance for Production Compaction Based on Agency’s Current Requirements
Statistics of IC-MV
7. IC Data Submittal Daily Data Submittal Native IC Data Exported IC Data All Passes Data Proof Data
Courtesy of Bomag
All Passes and Proof IC Data Courtesy of Sakai
8. Payment and Measurements Lump Sum Payment Itemized Payment Weekly IC Equipment Rental Hourly Rate for Roller Operator Measurement No. of calendar weeks roller furnished Unauthorized Work Compacted materials are unauthorized without QC data
Keys to Success Passion IC Champions within Agencies Patience It Takes Time! Communications Among Agency, Suppliers, Contractors, and Consultants Strategies Start with Low-Hanging Fruits
Thank You ! Lee Gallivan, P.E. HQ-Office of Pavement Technology Asphalt Pavement Engineer