Modeling and experimental evaluation of influence of aggregate blending on asphalt mixture strength

Performance of asphalt mixes is vastly influenced by their aggregate properties. The depletion and the high cost of transportation of high-quality aggregates prompt the use of locally available aggregate sources. One approach that has been followed by state highway agencies and contractors to encourage the use of locally available aggregate sources is to blend low- and high-quality aggregates. However, no method is available to these agencies to analyze the influence of blending on mixture properties and to decide on the allowable percentage of blending. Introduced is a modeling approach to study the effect of blending different percentages of high- and low-quality aggregates on the strength of asphalt mixes. Blending charts were developed to predict the change in mix strength given strength and percentages of blended aggregates. The model results were verified through comparisons with several laboratory tests, including tensile strength, Hamburg wheel-tracking device, dynamic modulus, and flow time.