About the research
Increased concern for environment and worker safety requires that alternatives be found to avoid working with hazardous materials. An alternative for the calibration method using mercury in Section 4 of AASHTO T 153/ASTM C 204 is needed. The objective of this project was to add an alternative method to AASHTO T 153. The new method must not use hazardous materials and be safer to use than the current method while maintaining the accuracy and precision of the current method.
The researchers concluded that mechanical devices can be use to measure and calibrate Blaine cells with sufficient precision to allow users to conduct measurements without the need to handle mercury, and proposed changes to AASHTO Test Method T 153 to allow use of physical measurements. The report was forwarded to AASHTO staff to make it available to the chair and members of the AASHTO Highway Subcommittee on Materials, and to consider adoption of the recommended changes.