01122326

Component

https://doi.org/10.3141/2116-03

http://scholar.google.com...kson&publication_year=2009

Time domain reflectometry (TDR) is one of the reliable methods to measure in situ moisture content of unbound base and subgrade materials. However, the waveform data obtained from the TDR device do not provide in situ moisture content directly. Rather, the data must be analyzed to determine volumetric moisture content, which is the final product of TDR-related technology; that is, a TDR trace is analyzed to determine the value of the associated dielectric constant, which depends on the soil surrounding the TDR probe affecting the moisture content determination. However, because existing methods to determine the dielectric constant and moisture content are immersed in systematic errors, a new approach was developed; it used the transmission line equation and a three-phase micromechanics approach to improve the accuracy of the interpretation of TDR data for calculating the dielectric constant and the moisture content. Because the system identification method used to calculate parameters in the new approach was an iterative solution scheme, a computational program was required to provide rapid, accurate, and repeatable calculation of parameters. To address this need, a program was developed to facilitate the calculation of dielectric constant, dry density, and moisture content using the micromechanics approach. Details regarding the feature, algorithm, and results of the program are provided.

01147419

09-3303

English

pp16-25

2009

Transportation Research Record: Journal of the Transportation Research Board

9780309126311

Print

Figures (11) ; References (12) ; Tables (1)

Algorithms; Base course (Pavements); Dielectric properties; Dry density; Mathematical models; Moisture content; Pavement layers; Subgrade (Pavements); Time domain reflectometers

Long-Term Pavement Performance Program; Seasonal Monitoring Program (LTPP)

Micromechanics

Geotechnology; Highways; Pavements; I42: Soil Mechanics

PRP, TRIS, TRB, ATRI

Jan 30 2009 7:42PM

• Capacities and Deflections of Laterally Loaded Shafts Behind Mechanically Stabilized Earth Wall
• Comparison of Stress States and Paths: Vibratory Roller-Measured Soil Stiffness and Resilient Modulus Testing
• Deformation Factors of Buried Corrugated Structures
• Evaluation of High-Capacity Composite Spun Piles
• Evaluation of the Zone of Influence and Stiffness Improvement from Geogrid Reinforcement in Granular Materials
• Fatigue Evaluation of Porous Asphalt Composites with Carbon Fiber Reinforcement Polymer Grids
• Full-Scale Evaluation of Geosynthetic-Reinforced Aggregate Roads
• Geogrid Base Reinforcement with Aggregate Interlock and Modeling of Associated Stiffness Enhancement in Mechanistic Pavement Analysis
• High-Capacity Piles at the Stony Creek Bridge Project
• Horizontal Drains in a Clay–Landslide Stabilization Test Program
• Instrumented Rollers to Assess Construction Quality on Texas Projects
• North Carolina Department of Transportation’s Practice and Experience with Design–Build Contracts: Geotechnical Perspective
• Stiffness-Based Assessment of Pavement Foundation Materials Using Portable Tools