00264687

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http://onlinepubs.trb.org...epubs/sr/sr140/140-011.pdf

This paper describes a research study of the flexural and fatigue properties of both gap-graded and continuously graded bituminous mixtures to establish the factors contributing to fatigue and the conditions under which gap-graded mixtures can be used to maximum advantage. Laboratory-prepared specimens and in situ measurements on a full-scale experimental road pavement were used to study the factors involved in the fatigue subsystem. In the laboratory tests an electrodynamic system of impulse loading was used on trapezoidal-shaped specimens. High-frequency seismic and ultrasonic methods emerged as valuable nondestructive techniques for the measurement of elastic moduli both in the field and in the laboratory. The relations between measured strains and deflections within the experimental pavement structure and theoretical predictions derived from present-day structural analysis techniques based on linear elastic and nonlinear finite-element procedures were established. The results showed clearly the necessity for taking into account the stress nonlinearity of the resilient modulus of the granular cushed-rock material in the base. On typical South African pavements it was shown that fatigue failure of bituminous surfaces occurs mainly under conditions of controlled strain. Therefore, proposals are made to modify current pavement design methods, including the more complex methods that take account of environmental conditions, traffic, material properties, and surface thicknesses. The proposals enable these methods to be applied to the design of thin (less than 50 mm) and intermediate surfaces and with the use of a computer program to predict the initiation of fatigue and the rate of deterioration of the surface stiffness caused by the propagation of cracks. /Author/

Appeared in Structural Design of Asphalt Concrete Pavements to Prevent Fatigue Cracking. Proceedings of a Symposium held January 22, 1973. 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

00815850

Huang, Yang H

pp 158-182

1973

Highway Research Board Special Report

52nd Annual Meeting of the Highway Research Board

030902160X

Print

Figures (13) ; References (36) ; Tables (3)

Bituminous mixtures; Computer programs; Cracking; Environmental impacts; Fatigue (Physiological condition); Field tests; Finite element method; Flexure; Forecasting; Laboratory tests; Materials; Measurement; Seismicity; Surfaces; Traffic; Ultrasonics

Crack propagation; Seismic investigations

Environment; Highways; Materials; Operations and Traffic Management; Pavements

TRIS, TRB, ATRI

Jan 9 1975 12:00AM

• CHARACTERIZATION OF FATIGUE BEHAVIOR
• EXAMPLES OF APPROACH AND FIELD EVALUATION: RESEARCH APPLICATIONS
• FAILURE CRITERIA DEVELOPED FROM AASHO ROAD TEST DATA
• FATIGUE LIFE PREDICTION
• FATIGUE SUBSYSTEM SOLUTION FOR ASPHALT CONCRETE AIRFIELD PAVEMENTS
• MATERIAL CHARACTERIZATION AND LAYERED THEORY FOR USE IN FATIGUE ANALYSES
• MECHANISTIC APPROACH TO THE SOLUTION OF CRACKING IN PAVEMENTS
• OTHER INPUT VARIABLES: TRAFFIC AND ENVIRONMENTAL
• PAVEMENT DESIGN SCHEMA
• PAVEMENT DESIGN: THE FATIGUE SUBSYSTEM
• RELATION BETWEEN CRACKING AND PERFORMANCE
• SUMMARY DISCUSSION