Abstract

Unintrusive measurement of field modulus and moisture content of roadway subgrade and fill materials greatly enhances field control during construction. Establishing a measurement method in a laboratory setting provides an initial assessment of a tool's possible usefulness in the field. an ultrasonic test system was used in this research in order to determine the wave velocities of cylindrical soil specimens in a laboratory setting in support of a Briaud Compactive Device (BCD) research project. the BCD is a non-destructive test method that can quickly determine soil modulus both in the laboratory and the field. Cylindrical soil samples of silt were compacted in two different molds: A standard proctor mold 152.4-mm (6-inch) diameter and a smaller 71.1 mm (2.8-inch) diameter mold. the p-wave and the s-wave velocities of samples manufactured in each of the molds were compared against sample moisture content and the dry unit weight. Trends in wave velocity versus moisture content were investigated using the two types of molds and compacting using two compactive efforts. It was found that specimens prepared in the two different molds generate similar trends of wave velocity versus moisture content. in general, the smaller compaction mold could be used for specimen preparation for ease in preparation, but care and experience are needed in order to match targeted dry unit weight values on a given compaction curve. Regardless of compaction mold sizes and compactive efforts, the wave velocities show the strongest correlation with moisture content. This ultrasonic test system is useful for calibration of the (BCD) in the laboratory setting and could be applied to testing of samples extracted from the field. © 2010 ASCE.

Department(s)

Civil, Architectural and Environmental Engineering

Keywords and Phrases

Silts; Subgrades; Ultrasonic methods; Velocity

International Standard Book Number (ISBN)

978-078441095-0

International Standard Serial Number (ISSN)

0895-0563

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Society of Civil Engineers, All rights reserved.

Publication Date

01 Dec 2010

Share

 
COinS