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Our refinery processes crude oil into a variety of products including asphalt, gas-oil, and feedstock. The process involves heating the crude oil under controlled conditions until it separates into fractions that meet certain specifications. Many of these fractions are sent on to other refineries for further processing.
The refinery produces and markets a wide variety of PG-asphalts, emulsions and cut back asphalt. Quality control and quality assurance is achieved through the operation of a fully AMRL accredited laboratory.
We make approximately 65% Asphalt, 25 % Gas-Oil and 10% Naptha.
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Perfomance Grade(PG) Asphalt-Products
The PG system addresses many of the limitations of the Penetration and Viscosity grading systems by focusing on the three specific pavement distress modes: rutting, fatigue cracking, and low temperature cracking. The climate conditions to which pavements are exposed is a very important element of the PG system. PG grade asphalt binders are graded according to the climatic conditions they will endure in the roadway.
Caltrans has selected four PG grades: 64-10, 64-16, 64-28, and 70-10.
PG 64-10 will perform from a high temperature of 64 ºC to a low temperature of – 10 ºC. |
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Our refinery produces:
| Asphalt Grade |
California Climate Regions |
| PG 64-10 |
Central Coast, Inland Valley, South Coast |
| PG 64-16 |
North Coast, Low Mountain, South Mountain |
| PG 70-10 |
Desert |
PG Tests and Specifications
The Performance Grade (PG) asphalt binder specifications measure physical properties of the material throughout its temperature range. The Strategic Highway Research Program (SHRP) introduced a test that measures the relative contributions of the viscous and elastic components of the asphalt binder.
Four different types of tests are used to measure the properties used in the PG asphalt binder specification: BBR, RV, DSR, and DTT. Different types of stress and strain are measured during these tests,
- BBR – Stress and Strain during bending in a creep test.
- RV – Stress and strain during a constant rate of shear test.
- DSR- Stress and strain during a dynamic shear test.
- DTT- Stress and strain in tension during a constant rate of elongation test.
Each of the tests is conducted under controlled temperatures and loading times. An important feature of the PG grading system is that it measures asphalt properties over a much broader range of aging conditions than previous grading systems. Short term aging to simulate hot mix hardening in the mix plant is accomplished with the Rolling Thin Film Oven (RTFO) test, which was adopted from the AR grading system. A new aging test, the Pressure Aging Vessel (PAV), was developed to simulate long-term aging in the field.
Greka Refining Company is committed to quality, service, dependability, and customer satisfaction. We are in the AASHTO proficiency sample testing program in addition to the AASHTO Accreditation Program (AAP).
