Construction Materials Testing
Physical and Chemical Testing
The Physical and Chemical Testing Section performs a multitude of quality control
tests of concrete aggregates, asphalt concrete aggregates, rock slope protection,
stabilized soil and native soil. Some of the major tests this section performs are
Sand Equivalent, Cleanness Value, Sieve Analysis, Hydrometer Analysis, Sulfate Content,
Specific Gravity, Direct Shear, pH content and LART. This section also determines
R-Value for structural sections and tests compressive strength of PCC cylinders,
shotcrete cubes and soil cement.
PCC Cylinder Compressive Strength
Relative Compaction
The Compaction Testing group performs in-place density tests at jobsites using a
Troxler nuclear density gauges. There are two subsections of this group: AC Compaction
Testing and Soils/AB Compaction Testing.
- Asphalt Concrete Compaction Group
The AC Compaction group performs in-place density tests with a Troxler thin-lift
density gauge. Relative Compaction is calculated using the maximum density of a
grade sample tested at the Materials Lab.
- Soils/AB Compaction Testing
This Compaction group performs in-place density tests with a Troxler soils density
gauge, obtains soil samples from the location of the test, and transports the soil
samples to the Materials Lab to determine the maximum density.
Asphalt Testing
The Asphalt Testing Section performs state-of-the-art physical and chemical testing
of bituminous mixes.
Independent Assurance Testing
The Independent Assurance Testing Section is responsible for implementing and administering
the materials testing (soil, PCC, AC aggregate, asphalt) certification program throughout
the Materials Lab - this includes producing certification materials such as written
exams and certification checklists for each test procedure performed by the lab.
As part of the certification program, the IAT Section is responsible for performing
annual witness tests with all of the technicians assigned to the Materials Lab.
In addition to managing the materials testing certification program, the IAT rep
also performs audits of private laboratories that perform any materials testing
on County of Orange projects to ensure established testing procedures are consistently
and accurately followed. The IAT rep reports directly to the Materials Engineer
and provides a monthly update on the progress of the Lab's certification program
as well as compliance of test methods by private labs.
Soil Compaction Testing
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