Asphalt Rice Test

Rice Test

The asphalt rice test was developed to help determine the percentage of air voids in an HMA sample, otherwise known as the theoretical maximum specific gravity of asphalt test. ASTM and AASHTO test methods determine the specific values to calculate the air voids and also show aggregate bitumen absorption.

The test (originally developed by engineer James Rice) ultimately provides a compaction target for the asphalt laydown based on air void percentage. These are a large factor in determining the ultimate quality of the asphalt – a low percentage can cause shoving and rutting of the pavement while a high percentage can cause the asphalt to damage from moisture and fatigue.

The rice test is an invaluable tool that is routinely used by DOTs, labs and asphalt producers. Refer to ASTM D2041 and AASHTO T209 testing standards for specific information and guidelines. Humboldt’s asphalt rice testing equipment is designed and built to high quality standards for durability and accuracy.

Vacuum Pycnometers – Used to determine maximum specific gravity of bituminous paving mixtures. Kits for different sample sizes, large capacity and in stainless steel are also available.

De-Airing and Vibrating Tables – Used for maximum specific gravity and density determinations of mixtures, and as an agitator in Rice testing to keep sample material loose for more reliable test results.

Vacuum Pumps – Remove the free air from samples while they are agitated to remove entrapped air. Humboldt features a variety of pumps specific to your application and aligning with appropriate ASTM and AASHTO specific gravity applications.

Rice Test Process Control – The AutoRice Controller is an automatic control unit allows lab technicians to conduct maximum specific gravity tests with the press of a button. The PumpSaver increases accuracy and repeatability for tests requiring a vacuum pump. The Digital Manometer replaces mercury-filled manometers used in Rice testing.

Specific Gravity Test Accessories – Air drying units, dessicants, de-airing flask attachments and a slow-release valve for pycnometers are also available.

For more detailed information about Marshall Testing, please visit our Asphalt Marshall Testing landing page.

Humboldt offers a variety of products for Asphalt Rice Testing, in-stock and ready to ship. If you have questions or need help selecting equipment, please call us at 1.800.544.7220 or use our Ask Humboldt form.