airfield, or the various tests that are associated with the
design or proportioning of concrete or asphalt-concrete
mixtures. Obviously, to do all of this testing, you must
make sure that your EAs are properly trained. If you
have been away from a construction battalion for some
time, you may even find it necessary to do some
refresher training yourself.
Work Assignments
As with the drafting and surveying section,
requests for materials testing can be made using the
engineering division work request (fig. 14-1). These
can then be posted to a work schedule and handled
using a priority-system method like that described
previously.
Not all of the work requests, however, will be
originated by a project supervisor or the QC division.
Many of them should start with you. For this to
happen, you must become thoroughly familiar with
each of the projects the battalion is tasked with. This
involves reviewing the project plans and
specifications to see what tests are needed and
reviewing all project schedules to know when the tests
are required. Having done this, you can generate the
work requests and post work to the schedule with
tentative start dates that can be adjusted as changes
occur. Obviously, you must coordinate closely with
the project supervisors and QC to know when changes
are needed.
Many of the materials tests are critical item tests
that must be performed at a given point in construction
before further construction work can proceed. For
instance, asphalt paving operations on a road or
parking area cannot start until the base material has
been compacted to meet specifications. Current
COM- SECONDNCB or COMTHIRDNCB and
battalion instructions pertinent to quality control state
minimum requirements and stress critical item
inspections and tests that must be performed during
construction. You should be particularly aware of
these so that project work will not be delayed for
materials testing.
You need to remember, too, that some tests are
dependent upon other tests; for example, the results
of in-place density testing using the nuclear
moisture-density meter must be compared with the
results of laboratory tests performed on the same
material. For these pretests, you will not receive a
work request; you must initiate them yourself. Never
wait until the last minute to have these tests performed
or you maybe the cause of unnecessary construction
delay.
Analyzing Test Results
All materials tests have a specific purpose, and
when carefully performed according to established
standard procedures should provide results that can
be reasonably expected. As a supervisor, you need
to know what the end purpose is before you can
decide what tests to perform and you need to know
what to expect from the tests. With this knowledge,
you are in a position that enables you to analyze the
results of each test performed. When a test results
in data that is greatly out of step with that expected,
then you need to determine the cause; for example,
if an in-place density test shows unexpectedly high
results, what happened? Was the test performed
improperly? Was a substance, such as cement,
added to the soil that greatly increased the density
of the in-place material as compared to previously
performed laboratory tests? These things can, and
do, sometimes happen.
In addition to analyzing the test results for accuracy
and validity, you sometimes need to place the test data
into a more usable form. Figure 14-6, for example,
shows California bearing ratio data that is presented in
a usable form. You can read about this in Materials
Testing, NAVFAC MO-330.
Training of Testers
Lower rated personnel assigned as materials
testers should be given assignments for spare-time
reading of printed sources on testing procedures.
Locally used data forms should be explained. New
personnel should be assigned to learning on-the-job
procedures in the laboratory and at the jobsite under
experienced personnel. The purpose of what is being
done should always be explained; for example, the
ultimate effect of soil tests on the work of highway
subgrading should be clearly shown. Some testing,
such as fieldtests for soils, require extensive practice
to become proficient. Even though field testing is a
requirement at the senior EA level, you should see to
it that the junior rated EAs get a chance to practice it
as often as possible under the watchful eye of an
experienced technician.
There is relatively little routine, day-to-day work
in testing since the work of the materials testing
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