Rapid Field Detection of Moisture Content for Base and Subgrade: Technical Report

Mixing and compacting soil and flexible base pavement materials at the proper moisture content is critical for obtaining adquate compaction and meeting construction specification requirements. This project sought to evaluate rapid non-nuclear techniques for measuring the moisture content on roadway base and subgrade materials.This report presents results from the final stages of testing in this project, which included 3 non-nuclear approaches, the nuclear gauge for comparison, and the over dry gravimetric moisture as the reference value. Researchers evaluated each test for bias, precision, and sensitivity, and then scored the devices according to bias, precision, sensitivity, cost, turnaround time, suitability for uncompacted materials, and suitability for compacted materials. With these scoring parameters, the data showed the moisture analyzer most suitable for implementation. The report presents a draft test method for measuring moisture content with the moisture analyzer. The test turnaround time is typically between 15 and 30 minutes.