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.
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.
Soil Compaction Testing
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.
