Harmonized Resilient Modulus Test Method for Unbound Pavement Materials

Abstract

A new laboratory test protocol for the measurement of resilient modulus of unbound pavement materials is described. This harmonized protocol combines the best features from four state-of-the-art resilient modulus test procedures in current use. The harmonized procedure most closely follows the recommended protocol proposed in NCHRP Project 1-28, Appendix E, with some exceptions. The main modifications deal with revised and more rational stress sequences and a more accurate stress-dependent resilient modulus predictive equation. Thirteen different predictive models and 25 sets of resilient modulus test data were evaluated as the basis for the recommended predictive equation.