company be hired to provide the QA testing for the
project. The cost of this testing to assure good
long-term performance is very small relative to the
overall cost of the construction, and especially
compared to the cost of a pavement failure.
Although not recommended, this guide specification
may be modified to require the Contractor to hire an
independent material testing laboratory to perform
the QA testing listed in this section. The results
would need to be forwarded daily to the Contracting
OfficerEngineer as the basis for acceptance and pay.
This should only be done if there is no way of
hiring an independent testing laboratory to perform
the QA testing.
The QA testing program includes material tests to
determine laboratory air voids and in-place density,
which are needed to determine percent payment. The
project engineer may choose to have additional tests
conducted by the QA test agency to monitor aggregate
gradation, asphalt content, Marshall stability and
flow. These tests would serve as a check to the
Contractor's QC testing. Marshall stability and
flow could be done at minimal cost since the
specimens have to be made anyway for laboratory air
void determination. This additional testing, if
conducted, is not included as part of this
specification since the parameters are not used as a
basis of pay.
For projects with less than 2000 total tons, the
entire project can be considered as a single lot.
In this case, sublot sampling could occur over
several days' production, which could lead to higher
sublot variability.
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The Government's Engineer's quality assurance (QA) program for this
project, specified below, will be separate and distinct from the
Contractor's quality control (QC) program specified above. Testing for
acceptability of work will be performed by the GovernmentEngineer or by an
independent laboratory hired by the Contracting OfficerEngineer, except for
grade and smoothness testing which shall be performed by the Contractor.
Acceptance of the plant produced mix and in-place requirements will be on a
lot to lot basis. A standard lot for all requirements will be equal to
2000 metric short tons. Where appropriate, adjustment in payment for
individual lots of hot-mix asphalt will be made based on in-place density,
laboratory air voids, grade and smoothness in accordance with the following
paragraphs. Grade and surface smoothness determinations will be made on
the lot as a whole. Exceptions or adjustments to this will be made in
situations where the mix within one lot is placed as part of both the
intermediate and surface courses, thus grade and smoothness measurements
for the entire lot cannot be made. In order to evaluate laboratory air
voids and in-place (field) density, each lot will be divided into four
equal sublots.
SECTION 02749
Page 30
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