Durham School of Architectural Engineering and Construction


Date of this Version

Fall 8-2011


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Construction, Under the Supervision of Professor Yong Cho. Lincoln, Nebraska: August, 2011

Copyright 2011 Ziqing Zhuang


Density is an important measure for hot-mix asphalt (HMA) pavement quality control. Traditionally, the nuclear gauge method is widely used in pavement density testing. However, some disadvantages of nuclear gauges (such as the handling, storage, and transportation of radioactive materials) have created the need of non-nuclear technology. This thesis evaluated the Pavement Quality Indicator (PQI) model 301, which was promised to be more efficient than the nuclear method. The PQI utilizes many electrical impedance principles by using the current going through the pavement to determine its density and moisture content. Test data were collected in the field during pavements, and cores were taken to the laboratory for further testing. A thorough investigation of calibration methods was also performed both in the lab, and on the field to improve the accuracy of the PQI’s results. Results showed that the PQI could be a better alternative to a nuclear gauge when the following benefits are considered: 1) economic savings, 2) faster data measurement, 3) no intense federal regulations, safety concerns, licensing and intense training, and 4) improved calibration techniques.

Advisor: Yong Cho