Details:

Alternative Title:
Use of FWD multi-load data for pavement strength estimation
Creators:
Kim, Y. R. ; Park, H.
Kim, Y. R. ; Park, H. Less -
Corporate Creators:
North Carolina State University. Dept. of Civil Engineering ; United States. Federal Highway Administration
North Carolina State University. Dept. of Civil Engineering ; United States. Federal Highway Administration Less -
Subject/TRT Terms:
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Deflection
Falling Weight Deflectometers
Fatigue(Materials)
Flexible Pavements
FWD(Falling Weight Deflectometers)
Loads(Forces)
Measuring Instruments
Pavement Conditions
Pavement Strength
Stress Analysis
Materials Tests
Pavement Performance
Performance Tests

Publication/ Report Number:
FHWA/NC/2002-006
Resource Type:
Research Paper
Geographical Coverage:
North Carolina
OCLC Number:
51004600
Edition:
Final Report; July 1999 - June 2001
Corporate Publisher:
North Carolina. Dept. of Transportation
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and Performance ; NTL-HIGHWAY/ROAD TRANSPORTATION-Materials ; NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATION ;
Abstract:
The objective of this study is to develop a mechanistic-empirical method for assessing pavement layer conditions and

estimating the remaining life of flexible pavements using multi-load level Falling Weight Deflectometer (FWD) deflections. A

dynamic finite element program, incorporating a stress-dependent soil model, was developed to generate the synthetic deflection

database. Based on this synthetic database, the relationships between surface deflections and critical pavement responses, such as

stresses and strains in each individual layer, have been established. A condition assessment procedure for asphalt pavements that

uses multi-load level FWD deflections has been developed using these relationships. The verification study was conducted using

field data. The results indicate that the proposed procedure can estimate the base and subgrade layer conditions. It was found

from the study for the nonlinear behavior of a pavement structure that an FWD test with a load of 12 kip or less does not result in

any apparent nonlinear behavior of the subgrade in aggregate base pavements. The study also indicated that the deflection ratio

obtained from multi-load level deflections may predict the type and quality of the base/subgrade materials. With regard to the

condition assessment of the asphalt concrete (AC) layer, the AC layer modulus and the tensile strain at the bottom of the AC

layer were found to be better indicators than deflection basin parameters.

The procedures for performance prediction of fatigue cracking and rutting were developed for flexible pavements. The

drastically increasing trend in fatigue cracking with time may not be predicted accurately using the proposed procedure. Such

trends may be due to the environmental effects and the inconsistent distress measurements. Predicted rut depths using multi-load

level deflections show good agreement with measured rut depths over a wide range of rutting. However, the procedure using

single load level deflections consistently underpredicts the rut depths. It was concluded that the rutting prediction procedure

using multi-load level deflections can estimate an excessive level of rutting quite well and, thus, improve the quality of prediction

for rutting potential in flexible pavements.

The layer condition assessment procedure and the remaining life prediction algorithms developed in this project were

incorporated into APLCAP (Asphalt Pavement Layer Condition Assessment Program) version 2.0, the VisualBasic program

developed under the NCHRP 10-48 project.


Format:
PDF
Funding:
HWY-00-04
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:245f78c2b35fef222bdf996c1255782a9072cbd777dbbadf34711f56028236bb
File Type:

Supporting Files

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