01550341

Component

https://doi.org/10.3141/2510-08

One of the main input parameters in the mechanistic design and analysis of pavement systems, the stiffness of unbound pavement material usually is moisture dependent. As a result, most unbound pavement layers exhibit seasonal variations in stiffness as the pavement moisture content changes over the year. Any realistic pavement design should take this variation into account. In unbound material with a high fines content, a change in moisture content can change the stress state because of suction effects. An enhanced predictive resilient modulus model is presented to account for seasonal variation by means of suction measurement. A silty sand subgrade soil was tested with a modified repeated load triaxial system under different moisture (suction) conditions, and a set of resilient modulus model regression parameters was determined. The capability of the model to capture seasonal variation in moisture content was evaluated further with field data. A series of falling weight deflectometer (FWD) tests with multilevel loads was conducted on an instrumented pavement structure in which the moisture content of the subgrade was changed by manipulating the pavement drainage condition. The resilient modulus values obtained from the model were compared with backcalculated stiffness data obtained from FWD tests conducted under different moisture conditions. Overall, agreement was good between the laboratory-based resilient modulus values and the backcalculated stiffness. The resilient modulus–suction model could efficiently capture the moisture content effects.

01587391

15-2716

English

pp 65–73

2015

Transportation Research Record: Journal of the Transportation Research Board

9780309369329

Print

Figures (8) ; References (24) ; Tables (1)

Backcalculation; Falling weight deflectometers; Mathematical models; Modulus of resilience; Moisture content; Pavement design; Regression analysis; Silty sands; Soil suction; Stiffness; Subgrade (Pavements)

Repeated load triaxial tests; Seasonal variations

Geotechnology; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I42: Soil Mechanics

PRP, TRIS, TRB, ATRI

Dec 30 2014 12:56PM

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• Climate Projections for Transportation Infrastructure Planning, Operations and Maintenance, and Design
• Effects of Particle Size and Fines Content on Thermal Conductivity of Quartz Sands
• Frost Depth: General Prediction Model
• Historical Analysis of Tunnel Approach Displacements with Satellite Remote Sensing
• Incorporating the Effect of Moisture Variation on Resilient Modulus for Unsaturated Fine-Grained Subgrade Soils
• Modified Unconfined Compression Testing System to Characterize Stress–Strain Behavior of Unsaturated Soils at Low Confining Stresses
• Resilient Modulus of Fine-Grained Soils for Mechanistic–Empirical Pavement Design
• Rock Slopes Asset Management: Selecting the Optimal Three-Dimensional Remote Sensing Technology
• Seasonal Effects on a Low-Volume Road Flexible Pavement