Mechanistic Interpretation of Nondestructive Pavement Testing Deflections
Hoffman, Mario Sergio
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/66882
Description
Title
Mechanistic Interpretation of Nondestructive Pavement Testing Deflections
Author(s)
Hoffman, Mario Sergio
Issue Date
1980
Department of Study
Civil Engineering
Discipline
Civil Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Engineering, Civil
Language
eng
Abstract
A method is proposed for the backcalculation of material properties in flexible pavements based on the interpretation of surface deflection measurements. ILLI-PAVE, a stress-dependent finite element pavement model, was used to generate data for developing algorithms and nomographs for deflection basin interpretation.
Over 11,000 deflection measurements for 24 different flexible pavement sections throughout the State of Illinois were collected and analyzed. Deflections were measured using the Benkelman Beam, the IDOT Road Rater, the Falling Weight Deflectometer, and an accelerometer to measure deflections under moving trucks. Loading mode effects on pavement response were investigated using dynamic and viscous pavement models. The factors controlling the pavement response to different loading modes were explained and identified. Correlations between different devices were developed. The study indicated that the Falling Weight Deflectometer response best simulates pavement response under a moving truck. The Road Rater, because of its harmonic loading without rest periods and the static superimposed load, induces a stiffened response of the pavement-subgrade system. The quasi-static loading in Benkelman Beam testing induces the highest deflections in most pavements.
The proposed evaluation procedure is illustrated for three different flexible pavements using deflection data collected on several testing dates. Agreement is achieved between back-calculated material properties and laboratory determined properties. Agreement is also obtained between measured and predicted deflection basins. The backcalculated parameters using the proposed evaluation procedure can be used as input for overlay design. The change in the stress state in the pavement-subgrade system effected by a change in the pavement cross section (overlay) is accounted for by the nonlinear stress-dependent characterization of the granular base material and subgrade soil in the ILLI-PAVE structural pavement model.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
