In 1986 aashto adopted the resilient modulus test for use in thedesign of pavement structures to determine properties of roadbed soil and pavement components (aashto t274-82). The criticism that followed this adoption has resulted in the publication of several papersaimed at resolving the problems generated by the test method. The strategic highway research program's published modifications to the test procedure are examined, in paticular. In addition, the experience gained in calibrating a resilient modulus testing system--as well as the results obtained from a pilot test program with cohesive soil--is presented. Finally, the comparison results obtained from testing companion cohesive specimens using the resilient modulus test and torsional testing techniques are reported. The results indicate that(a) strong uniform contact between the specimen and the top and bottom caps of the triaxial cell is required for accurate measurement of modulus; (b) synthetic samples of known properties can be useful for the detection of equipment compliances, as well as for assessing a reliable system; and (c) the resonant column and torsional shear apparatus provides a basic approach to characterizing pavement materials--an approach that was useful for comparison with the resilient modulus test. This paper appears in transportation research record no. 1307, Pavement analysis, design, rehabilitation, and environmentalfactors 1991.
Abstract