Volume 33, Issue 4 (July 2010)
Integrated Air Trap and Volume Gauge for Axis Translation Systems
This Technical Note presents the design detail of a combined air trap and volume gauge burette used for flushing air bubbles from under ceramic disks in axis translation systems that are used to measure or apply matric suction to unsaturated soil specimens. Axis translation systems are commonly used in the testing of unsaturated soils to subject soil specimens to matric suction values greater than 1 atm. Diffused air may come out of solution and accumulate below the ceramic disk of the axis translation system, prompting to provide a flushing system to remove them. An apparatus consisting of two concentric glass tubes, alongside a graduated scale, two water vessels permitting the isolation of the water phase to reduce moisture exchange with the surrounding atmosphere, and connected to the flushing groove below the ceramic disk of the axis translation system through two plastic tubes was developed. The apparatus described permits an accurate measurement of the volume of water expelled from the specimen and can allow for the volume of diffused air flushed out.