00469596

Component

http://onlinepubs.trb.org...trr/1987/1136/1136-010.pdf

https://scholar.google.co...iggs&publication_year=1987

To load-zone roads properly, mechanisms involved in the deterioration of pavements must be understood and monitored. The state of practice in nondestructively evaluating pavement systems is limited to determining changes in modulus profiles. For secondary roads, deflection basin methods (such as falling-weight deflectometer (FWD) and Dynaflect) are most effective in determining moduli of subgrades and are not as sensitive to moduli of the surface and base layers. On the other hand, the Spectral-Analysis-of-Surface-Waves (SASW) method is quite sensitive to moduli in the upper layers. In addition, the SASW method has the advantage of allowing the pavement system to be divided into numerous layers, say 10 to 15 in the upper 3 ft, so that detailed profiles can be determined. With this resolution, it is possible to delineate changes in the modulus profile from one measurement to the next. To illustrate the use of the SASW method on secondary roads, two sites were tested to determine the possible reasons for one section rutting and the other not. The rutted section was found to have layers with lower moduli or in which moduli appeared to be decreasing and hence possibly causing deterioration of the section. Also, the softening effect of rain on these pavements was studied. Softening occurred mainly in the upper portion of the subgrade. The FWD device was also used to determine moduli of the two sections. Moduli from the FWD tests are substantially lower than those from the SASW tests in the base layers mainly because of nonlinear behavior created during FWD testing. However, moduli of the subgrades are quite similar because of the linear behavior of this material in both types of tests. Deflection basins based on moduli of SASW tests are also compared with the FWD deflection basins. If the nonlinear effects are considered, the deflection basins based on moduli evaluated by the SASW tests compare well with those measured by the FWD device.

Publication of this paper sponsored by Committee on Flexible Pavement Design. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01418141

pp 96-107

1987

Transportation Research Record

0309045169

Print

Figures (13) ; References (10) ; Tables (6)

Alternatives analysis; Deflection; Falling weight deflectometers; Modulus of elasticity; Nondestructive tests; Pavement layers; Rainfall; Rayleigh waves; Ruts (Pavements); Secondary roads; Softening point; Spectrum analysis; Subgrade (Pavements)

Spectral analysis of surface waves

Causes; Rut

Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces

TRIS, TRB, ATRI

Jul 31 1988 12:00AM

• ANALYSIS OF AXLE LOADS AND AXLE TYPES FOR THE EVALUATION OF LOAD LIMITS ON FLEXIBLE PAVEMENTS
• ANALYTICAL EVALUATION OF VARIABLES AFFECTING SURFACE WAVE TESTING OF PAVEMENTS
• COMBINED EFFECT OF TRAFFIC LOADS AND THERMAL GRADIENTS ON CONCRETE PAVEMENT DESIGN
• DYNAMIC RESPONSE OF PAVING MATERIALS
• EFFECT OF CONCRETE OVERLAY DEBONDING ON PAVEMENT PERFORMANCE (DISCUSSION AND CLOSURE)
• ENGINEERING PROPERTIES OF ROLLER-COMPACTED CONCRETE
• FEACONS III COMPUTER PROGRAM FOR ANALYSIS OF JOINTED CONCRETE PAVEMENTS
• FIELD ANALYSIS OF RUTTING IN OVERLAYS OF CONCRETE INTERSTATE PAVEMENTS IN ILLINOIS
• NINE-YEAR PERFORMANCE EVALUATION OF ARIZONA'S PRESTRESSED CONCRETE PAVEMENT
• RELIABILITY OF THE FLEXIBLE PAVEMENT DESIGN MODEL
• THICKNESS DESIGN OF ROLLER-COMPACTED CONCRETE PAVEMENTS (DISCUSSION AND CLOSURE)