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1COMPLETE QUALITY ASSURANCE (QA) TESTING AND INSPECTION
ITEM #10, OAPC TOP 10 LIST WAYS TO GET MORE DURABLE HMA PAVEMENTS
Presented by
Doubra Ambaiowei, Ph.D., P.Eng., MCSCEORBA, OAPC - Council of ORBA, Technical Director
OAPC TOP 10 LIST – QUICK OVERVIEW2
A REMINDER: DOWNLOAD OAPC PUBLICATIONS
3
www.onasphalt.orgLook Under Publications & Education Section
QUALITY FACTORS IN HOT MIX ASPHALT
ENGINEERING
What is Quality Asphalt Pavement?
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✓ A Durable Pavement
✓ A Smooth Ride
✓ A Safe Pavement
✓ A Performing Pavement
QUALITY CHALLENGES
What Are the Challenges?
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✓ Low-bid Contract Practices
✓ Limited Budgets
✓ Use of Substandard Materials
✓ Specification Proliferations, et.al
CONTRACTUAL TESTING REQUIREMENTS6
◼ Preliminary Design Testing
Ensures prospective material sources can satisfy specification
requirements.
CONTRACTUAL TESTING REQUIREMENTS7
◼ Job Mix Control Testing – Mix Design Development
Ensures the paving mixture designed under the job-mix formula meets
all specification requirements.
CONTRACTUAL TESTING REQUIREMENTS8
◼ Job Mix Control Testing – During Production
Ensures the paving mixture produced under the job-mix formula meets
all specification requirements.
CONTRACTUAL TESTING REQUIREMENTS9
◼ Construction Control Testing
Performed as a routine and periodic item of inspection during/post
paving.
QUALITY ASSURANCE (QA) TESTING DEFINED10
• According to TRB’s Research Circular, No. E-C010 and E-C173, QA
is an all-encompassing term, that includes: “Quality Control (QC)”,
“Acceptance”, Inspection, and “Independent Assurance (IA)”.
• QA consists of all the planned and systematic actions necessary to
provide adequate confidence that a product or service will satisfy
given requirements for quality.
QUALITY ASSURANCE (QA) TESTING DEFINED11
Quality Control (QC):
• Consists of QA actions to ensure
materials and products conform
to the specification and/or end
result requirements; whether
manufactured or processed by
the contractor or procured from
suppliers or subcontractors.
Acceptance:
• Includes sampling, testing, and
the assessment of test results to
determine whether or not the
quality of produced material or
construction is acceptable in
terms of the specifications.
Inspection:
• Consists of observing and
monitoring production and
paving operations to ensure
compliance with plans and
specifications.
• Effective inspection at every
stage of the operation can be
the difference between a poor or
excellent performing pavement.
Independent Assurance (IA):
• These are third party activities
requiring an independent and
unbiased assessment of process
control, acceptance, and
inspection procedures, to verify
reliability.
IMPORTANCE OF SAMPLING AND TESTING12
✓ Proper Sampling is CRITICAL for any Product Testing
✓ Quality of Sample = Quality of Test Result
✓ Test in Accordance with Appropriate and Applicable Governing Standards
A REMINDER: PREMATURE PAVEMENT
FAILURES
TTI’s forensic investigation revealed three primary causes for the
pavement failures:
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o The Lack of bonding between layers of HMA;
o Cracks reflecting from existing lower pavement layers through asphalt overlays; and
o Dense aggregate gradations that do not provide sufficient room for the asphalt binder in the mixture or coarse gradations which may be sensitive to asphalt content, thus limiting the amount of asphalt in the mixture and which may be overly permeable.
QUALITY OF ASPHALT REVIEW: FINDINGS
SPECIFIC TO QA TESTING
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◼ Generally not enough qualified inspectors to provide adequate supervision and inspection of road pavement contracts.
◼ Perception on underbidding on projects in anticipation of “getting away with cutting corners”, and negative effects of outsourcing QA roles.
◼ Transferred risk of errors and self-policing.
◼ General consensus that QA processes and practices are a significant contributing factor to poor asphalt quality.
QUALITY OF ASPHALT REVIEW: RECOMMENDATIONS SPECIFIC TO QA TESTING
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◼ Development of acceptable QA process and a specific test that enables owners to independently verify, weigh, control, and record the quantity of RAP, REOBs etc., that goes into hot mix asphalt in the plant.
◼ Design and enforce stronger independent QA inspection programs at refineries producing AC, and at independent AC supplier facilities (AC terminals).
◼ Collaborate to design and provide specific training to municipal and industry’s QA/QC inspectors.
◼ Collaborating to review and support recommendations on increasing the frequency of testing, and the minimum required ratio of qualified municipal owner QA inspectors.
Towards Quality Asphalt16
What We Are Doing?
Towards Quality Asphalt17
What is Coming?
TO CONCLUDE18