Gradation and Moisture Effects on Resilient Moduli of Aggregate Bases

Abstract

Resilient modulus (M_R) which properly characterizes the load-deformation response of pavement materials under traffic loading, is evaluated. The M_R values due to three different gradations and three different moisture contents were investigated for the Richard Spur and the Sawyer aggregates, which are commonly used in Oklahoma as the subbase or base materials of roadway pavements. The three gradations were finer limit, median, and coarser limit, as specified by the Oklahoma Department of Transportation for Type A aggregate. The three moisture contents selected are optimum moisture content (OMC), 2 percent below OMC, and 2 percent above OMC. To investigate the variability of the test results, six duplicate M_R tests under identical conditions were performed for each case by using the AASHTO T294-94 method. Furthermore, the material properties, K₁ and K₂, which are required input in the AASHTO pavement design equation, were evaluated for the M_R values obtained. Finally, multiple linear regression models for predicting the M_R values of the two aggregates were established.

Get full access to this article

View all access options for this article.

References

AASHTO Guide for Design of Pavement Structures. AASHTO, Washington, D.C., 1993.

Raad

, Minassian

G. H.

, and Gartin

. Characterization of Saturated Granular Bases Under Repeated Loads. In Transportation Research Record 1369, TRB, National Research Council, Washington, D.C., 1992, pp. 73–82.

Rada

, and Witczak

W. M.

. Comprehensive Evaluation of Laboratory Resilient Moduli Results for Granular Material. In Transportation Research Record 810, TRB, National Research Council, Washington, D.C., 1981, pp. 23–33.

Zaman

M. M.

, Chen

D. H.

, and Laguros

J. G.

. Resilient Moduli of Granular Materials. Journal of Transportation Engineering, Vol. 120, No. 6, 1994, pp. 967–988.

Thompson

M. R.

, and Smith

K. L.

. Repeated Triaxial Characterization of Granular Bases. In Transportation Research Record 1278, TRB, National Research Council, Washington, D.C., 1990, pp. 7–17.

Mohammad

L. N.

, Puppala

A. J.

, and Alavilli

. Influence of Testing Procedure and LVDT Location on Resilient Modulus of Soils. In Transportation Research Record 1462, TRB, National Research Council, Washington, D.C., 1994, pp. 91–101.

Chen

D. H.

, Zaman

M. M.

, and Laguros

J. G.

. Resilient Moduli of Aggregate Materials: Variability due to Testing Procedure and Aggregate Type. In Transportation Research Record 1462, TRB, National Research Council, Washington, D.C., 1994, pp. 57–64.

Rahman

, Thomas

, and Zaman

M. M.

. Field Evaluation of Drainable Bases in Oklahoma. ORA Report 125-4299, School of Civil Engineering and Environmental Science, The University of Oklahoma, Norman, 1996

Burczyk

J. M.

, Saibati

K. K.

, Sprecher

R. A.

, and Farrar

M. J.

. Factors Influencing Determination of a Subgrade Resilient Modulus Value. In Transportation Research Record 1462, Washington, D.C., 1994, pp. 72–78.

10.

Elfino

M. K.

, and Davidson

J. L.

. Modeling Field Moisture in Resilient Moduli Testing. Special Technical Publication Resilient Moduli of Soils: Laboratory Conditions, ASCE, 1989.

11.

Huang

Y. H.

Pavement Analysis and Design. Prentice-Hall, Englewood Cliffs, N.J., 1993.

12.

Oklahoma Department of Transportation. Standard Specifications for Highway Construction, Oklahoma City, 1996.