Use this specification for
Items 451,
452,
305,
and 511
when the bid item description requires QC/QA. This specification defines the minimum
Quality Control Plan (QCP) requirements, the
Contractor’s minimum quality control (QC) materials testing, and the
Department’s quality assurance (QA) materials verification testing
requirements.
The Contractor will develop a
QCP to ensure that all materials and construction
practices for the item will conform to the specifications. Establish the responsibilities, duties, and
frequency for both in-process controls and quality control testing at the concrete’s
source and at the job site. This plan is to be reviewed by the Engineer for
compliance and then accepted. See 455.06
for the submission time requirements for the Contractor’s QCP.
This section outlines the
minimum QCP requirements for any QC/QA Concrete that
is to be produced. The QCP submitted by the
Contractor should, at a minimum, contain the content listed in 455.02.
The QCP should be reviewed by the Engineer for
compliance with this section. The Engineer also should ensure that the content
of the QCP is acceptable prior to approval.
This section outlines the
additional requirements that must be added to the Contractor’s QCP when placing concrete for structures under Item 511.
The Engineer should review the QCP to ensure that at
a minimum, each item listed in 455.03
is contained in the QCP and is acceptable prior to
approval. While most of the items listed in 455.03
have clear and definable measures, the following list provides some additional
guidance on specific items:
Ensure the QCP defines Lots and Sublots in
accordance with 455.03.A.
Approach slab concrete would be included with the lots for superstructure deck
concrete, except parapet concrete would be considered separately. There should
be at least three sublots of not more than 50 cubic
yards in a lot. Ensure the QCP meets the minimum
requirements of 455.03.A,
including sampling, testing, and documenting Air Content, Slump, and
Compressive Strength. Sample concrete at point of discharge
and placement. All curing, transporting, capping and testing of
compressive strength cylinders shall conform to ASTM standards. An AMRL laboratory must perform the compression testing. If
the Contractor is proposing to use maturity for falsework
removal and opening to traffic, they must provide the maturity curve per Supplement
1098.
Ensure the QCP provides the minimum information required by 455.03.B,
including procedures, methods and equipment to deliver, place, consolidate,
finish, protect, cure and groove the structural concrete.
This section lists the QC
testing information that should be provided to the Engineer. The air content
results must be sent to the Engineer within 1 day of completing the testing, and
the compressive strength results within 5 days of completing the testing.
This section outlines the
additional requirements that must be added to the Contractor’s QCP when placing concrete for pavements under Items 305,
451,
or 452.
The Engineer should review the QCP to ensure that at
a minimum, each item listed in 455.04
is contained in the QCP and is acceptable prior to
approval. While most of the items listed in 455.04
have clear and definable measures, the following list provides some additional
guidance on specific items:
A. Division of Pavement into Lots: Ensure the QCP defines Lots in accordance with 455.04.A
and Supplement
1064.
B. Division of Lots into Quality Control Sublots: Ensure
the QCP provides the placement sequence and placement
widths for the pavement work. Ensure the QCP defines
the sublots in accordance with 455.04.B
and Supplement
1064.
C. Material Control Requirements: Ensure the QCP meets the
minimum requirements of 455.04.C.
Plant verification intervals for portable plants should be defined by the
Contractor but may require modification if issues arise during production.
Tests performed during paving operations should at least comply with the
minimum requirements but could be more frequent.
D. Pavement Cores for Compression and Thickness: Ensure the QCP provides the minimum information required by 455.04.D.
per 451.18.B
Strength cores must be tested at 28 to 90 days of age. The QCP
should define the age for obtaining and testing cores within these limits.
E. Concrete Strength: The QCP should state the AMRL
accredited laboratory that test core strengths. The Engineer should validate
the accreditation and approve the reporting time frame and method.
F. Construction Process Requirements: Most
of the items listed in 455.04.F
have specific requirements from 305,
451,
or 452
that must be met. The Contractor’s QCP should not
only list the requirements from the related specification, but also state the
methods, materials, and/or equipment that will be used to ensure compliance.
The Engineer should cross-check each item listed with the related specification
prior to acceptance.
G. Reporting Requirements: This section
lists the daily QC testing information that should be provided to the Engineer.
The Engineer should approve the forms and methods used to transmit the
information and to whom it will be sent.
The Engineer will perform
Quality Assurance sampling and testing as specified or as deemed necessary.
Following proper procedures in determining random sample locations, sampling,
handling, and testing are vital to the process. The results of this testing
will be used to validate or invalidate the Contractor’s QC sampling and testing
for payment.
The
Engineer should use the table in Supplement
1127 or a random number generator to determine a random number for each sublot to determine from which load the QC sample will be
taken. The Contractor should not be made aware of the QA random sample
locations until just prior to sampling.
The
Engineer will perform side-by-side air and slump field testing with the Contractor
and compare results. If the difference between the Department’s and the
Contractor’s test result is greater than the tolerances listed below, the
Contractor and Engineer will determine the reason for slump or air content
differences and make necessary adjustments. The Engineer may stop the placement
until the reason for the difference is established and corrected. The Engineer
will check one of the first three loads delivered. Once the results are within
the tolerances listed below, the Engineer may reduce the QA sampling and
testing frequency to 10 percent of the Contractor’s subsequent QC tests.
Slump
±1 inch (25 mm)
Air
Content ±1%.
The Engineer will obtain
compressive strength QA samples from the same location as the Contractor’s
quality control samples at a frequency of one QA sample for every 10 sublots or at least one per lot. The Engineer will make six
4- by 8-inch (100 x 200 mm) cylinders for each sample. The Engineer will mark
the cylinders with identification and the Contractor shall provide initial
curing at the project.
After the initial curing at
the project site, deliver three QA cylinders to the Department’s Laboratory and
three QA cylinders to the AMRL accredited laboratory
for standard curing and testing. The
Accredited Laboratory will test the QA sample and the QC sample and report the
test results on the form accepted by the QCP.
Distinguish the QA from the QC results for the sublot.
The Engineer will compare and
verify that the Department tested QA, Contractor tested QA, and the matching QC
test results are within 14 percent of the Departments QA result. If the
comparison is favorable, the Contractor QC testing is considered verified.
When the comparison of the
results are more than 14 percent, investigate the results with the Engineer to
determine the reason for the difference.
If the reason for the difference cannot be determined to the Engineer’s
satisfaction, the Engineer will require the Contractor to either non-destructively
test or core the concrete represented by the cylinder tests to determine
compressive strength. Hire an independent laboratory to perform this additional
testing. The Engineer will witness the testing and evaluate the results. The
Department will reimburse the Contractor for all testing costs when the
Department’s results are in error. If the QC results are found to be valid, use
the QC results. If the QC results are
not valid, use the core results to determine the compressive strength values
for pay factors, 511.22.
The
Engineer should randomly choose at least 10 percent of the Contractor’s
QC samples to perform side-by-side quality assurance testing of the air
content. The results of the Department’s and Contractor’s tests should compare
to within ±1 percent. If the results do not compare, the Engineer should stop
placement until the reason for non-comparison is determined and corrected.
The
Engineer will randomly select
one out of every 10 Contractor QC core locations to have an
additional core obtained as a QA strength sample according to Supplement
1127. The Engineer should monitor
the cutting and take immediate possession of the QA core. The QA core sample
will be cured and tested on the date specified by the Contractor. If the
Department’s QA core results the matching Contractor’s QC core results compare
to within 13 percent, the Contractor QC is verified. If the
results do not compare to within 13 percent, follow the procedure as outlined
in 455.05.
The Contractor should submit
the proposed QCP to the Engineer for acceptance at
least 10 days prior to placing concrete.
If the submission is not found acceptable, the Contractor is required to
revise and resubmit the QCP and allow another 10 days
for review and acceptance. This may require the Contractor to reschedule a
concrete pour.
The QCP
acceptance is based on the concept that the proposed QCP
procedures will provide work which meets all specification requirements. If the accepted QCP
is not being followed, the Engineer will require compliance or resubmittal of
any modifications for review and acceptance.
When the actual work produced
by the QCP does conform to specification
requirements, the Engineer will require modification of the QCP
to return the work to conformance. The
Engineer must notify the Contractor when QCP
modifications are required and work should not continue until the Engineer has
accepted the QCP changes proposed by the Contractor.
The cost of developing and
implementing the QCP is incidental to the cost of the
concrete sold with the QC/QA requirement.
1. Document all submission, rejection, acceptance,
notification, or revision dates for the Contractor’s QCP.
2. Document the date of receipt of all Contractor QC
reports.
a. Document the quantities of concrete for payment and
the test results in a Site Manager Sample.
i.
When documenting
Contractor test results, only input test screen. When reporting Contractor
reported test results, only complete test screen PCC
INSPECTOR DAILY REPORT TE45 PART 2 – TESTS.
3. Document the random number, sample location, date,
test results, and comparison results for all QA samples obtained and tested.
4. Record results of beam breaks and opening to traffic.
5. Document on CA-C-2
or other approved forms.