Analysis of Resilient Modulus of Dense- and Open-Graded Aggregates

Abstract

The results of analyses of laboratory resilient modulus testing conducted on dense-graded and open-graded aggregates are presented. The testing program included three different aggregate materials (crushed limestone, natural stone, and slag), five different gradation specifications, and three different moisture conditions (dry, moist, and saturated). In addition to the five aggregate specifications, test specimens were prepared so that they would satisfy the lower, central, and upper bounds for the gradations. Resilient modulus tests were conducted as closely as possible according to Strategic Highway Research Program Protocol P-46 (AASHTO T 294-92 I). The test results were analyzed using log-linear regression analysis with two-parameter (bulk stress) and three-parameter (bulk stress and octahedral shear stress) expressions for resilient modulus. The results of the testing indicate that the resilient modulus of aggregates and regression constants vary significantly depending on the type of material and vary less significantly depending on material gradation and moisture condition. The natural stone aggregates had the higher moduli and the slag aggregate had the lowest moduli. The resilient modulus does not vary significantly as the moisture content increases unless the aggregate becomes saturated. The R² values are consistently higher using a three-parameter expression than a two-parameter expression.

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References

Randolph

B. W.

, Heydinger

A. G.

, and Gupta

J. D.

. Permeability and Stability of Base and Subbase Material. Draft Report. Department of Civil Engineering, University of Toledo, Toledo, Ohio, 1995.

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

Yoder

E. J.

, and Witczak

M. W.

. Principles of Pavement Design, 2nd ed. John Wiley and Sons, New York, 1975.

Resilient Modulus of Unbound Granular Base/Subbase Materials and Subgrade Soils—SHRP Protocol P46 (AASHTO Designation: T 294-92 I), FHWA, U.S. Department of Transportation, 1992.

Interim Specifications for Transportation Materials and Methods of Sampling and Testing, AASHTO, Washington, D.C., 1992.

Sargand

S. M.

, Hazen

G. A.

, Wilson

B. E.

, and Russ

A. C.

. Evaluation of Resilient Modulus by Back-Calculation Technique. Department of Civil Engineering, Ohio University, Athens, Oct. 1991.

Hicks

R. G.

, and Monismith

C. L.

. Factors Influencing the Resilient Response of Granular Materials. In Highway Research Record 345, HRB, National Research Council, Washington, D.C., 1971.

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.

Rada

, and Witczak

M. W.

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

10.

Monismith

C. L.

, Epps

J. A.

, Kasianchuk

D. A.

, and McLean

D. B.

. Asphalt Mixture Behavior in Repeated Flexure. Report TE 70-5. University of California, Berkeley, Jan. 1972.

11.

Albright

Evaluation of Crushed Aggregate Specifications Used by the Alaska Department of Transportation and Public Facilities. M.S. thesis. Department of Civil Engineering, Oregon State University, Corvallis, 1986.

12.

Zhou

, Moore

, Huddleston

, and Gower

. Free Draining Base Materials Properties, Research Unit/Pavements Unit, Oregon Department of Transportation, Salem, March 1992.