Materials Testing

Physical and Chemical Testing

PCC Cylinder Compressive Strength

PCC Cylinder Compressive Strength

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

Soil Compaction Testing

Asphalt Testing

The Asphalt Testing Section performs state-of-the-art physical and chemical testing of bituminous mixes.

Independent Assurance Testing

Independent Assurance Testing (IAT) program allows the Caltrans Independent Assurance (IA) personnel to test the Materials Lab engineering technicians who are qualified to perform Caltrans tests and provide a Certificate of Testing Proficiency.  The also allows the Caltrans IA section of the Materials Lab to request any Architect-Engineers retained by OC Construction to perform materials testing on public works facilities within County's jurisdiction for their Caltrans certification of materials laboratory and their engineering technicians.