Laboratory Resilient Modulus Measurements of Aggregate Base Materials in Utah

16400372015PDFTech ReportUT-16.1212-9110W.U. no. 5H07690HModulus of resilienceAggregatesBase course (Pavements)Subbase (Pavements)Subgrade (Pavements)Mechanistic-empirical pavement designAggregate Base MaterialCalifornia Bearing RatioMechanistic-Empirical Pavement DesignResilient ModulusUtahUnited StatesUtah. Dept. of Transportation. Research DivisionGuthrie, W. SpencerJackson, Kirk D.Knighton, Jaren T.Brigham Young University. Dept. of Civil and Environmental EngineeringUtah. Dept. of TransportationUnited States. Federal Highway AdministrationUS Transportation CollectionThe objectives of this research were to 1) determine the resilient modulus of several representative aggregate base materials in Utah and 2) investigate correlations between laboratory measurements of resilient modulus, California bearing ratio (CBR), and other properties of the tested materials. Two aggregate base materials were obtained from each of the four Utah Department of Transportation (UDOT) regions. Important material properties, including particle-size distribution, soil classification, and the moisture-density relationship, were investigated for each of the sampled aggregate base materials. The CBR and resilient modulus of each aggregate base material were also determined. After all of the data were collected, a set of independent predictor variables was analyzed using both stepwise regression and best subset analysis to develop a model for predicting resilient modulus. For the aggregate base materials tested in this research, the average resilient modulus varied from 16.0 to 25.6 ksi. The test results show that resilient modulus and CBR are not correlated for the materials tested in this research. Therefore, a new model was developed to predict the resilient modulus based on the percent passing the No. 200 sieve, particle diameter corresponding to 30 percent finer, optimum moisture content, maximum dry density (MDD), and ratio of dry density to MDD. Although the equation may not be applicable for values outside the ranges of the predictor variables used to develop it, it is expected to provide UDOT with reasonable estimates of resilient modulus values for aggregate base materials similar to those tested in this research