MOISTURE AND UNIT WEIGHT READINGS FROM A COMPLEX IMPEDANCE MEASURING INSTRUMENT

• Main Author: Jenkins, Kirk Andrew
• Format: Others
• Published: UKnowledge 2013
• Subjects: Electromagnetic; Electrical Density Gauge; Nuclear Density Gauge; Quality Control; Complex Impedance Measuring Instrument; Civil Engineering; Geotechnical Engineering
• Online Access: http://uknowledge.uky.edu/ce_etds/12; http://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1016&context=ce_etds

Complex Impedance Measuring Instruments (CIMI’s) are non-nuclear devices that calculate the dry unit weight and moisture content of soil by means of electromagnetic wave propagation theory. Unlike nuclear based test devices, these devices do not require certification or elaborate maintenance to own and operate. CIMI operation requires a soil specific calibration process where soil moisture and unit weight are correlated to electrical parameters. A new, smaller acrylic mold was developed as an alternative calibration tool to the manufacturer’s recommended mold. Calibrated soil models were generated using manufacturer recommended procedures as well as new procedures involving an acrylic mold. Models were then tested for accuracy. The new procedure outperformed the manufacturer’s procedure. Another small, acrylic mold was used to investigate the relationship between CIMI readings and soil parameters. Using several samples from four soils, the relationship between moisture, unit weight, and some electrical parameters was characterized. This characterization was then used to create a new, accurate calibration procedure.