Parametric Correlations between Aggregate Gradation and Mix Design Properties of Cold Mix Asphalt

Abstract

This study aimed to establish a correlation between the gradation characteristics and mix properties of Cold Mix Asphalt (CMA) by evaluating the gradation. The major scope of this study included the selection of aggregate gradation envelope, characterization using analytical methods, determination of mix design parameters of CMA, and establishing a correlation between aggregate gradation and mix design properties of CMA. Initially, three gradations with different Nominal Maximum Aggregate (NMAS) sizes and sieve size distributions were selected for evaluation. Next, the three gradations were normalized analytically to make them comparable and then were characterized based on Continuous Maximum Density (CMD) plot. After that, the mix design was carried out to determine the key mix design parameters in the laboratory. To examine the impact of the gradation characteristics on mix design parameters, a correlation analysis was conducted for CMA. The study findings revealed that void properties and mix design constituents exhibit a strong positive correlation with the gradation characteristic. Furthermore, predictive models were developed as a function of the gradation characteristic CMD Area. These predictive models can also be utilized to predict the trial mix constituents and design the aggregate gradation as per requirements.