Asphalt Mix Design Optimization for Efficient Plant Management

The role of aggregate gradation in hot-mix asphalt performance is well documented in the literature. Yet the Bailey method is the only tool available for guidance on aggregate gradation selection for optimal performance. Also, there is a lack of tools for design engineers and plant managers of quarry sites to manage stockpile inventory levels and control cost of aggregate used in asphalt mixes. This work presents a linear programming model of the asphalt mix design problem and a numerical algorithm to solve the model. The algorithm is implemented in MATLAB as an asphalt mix design optimization (AMIDO) program. The program is successfully verified with an example. The results show that using the Bailey method alone results in suboptimal results and that cheaper mixes with similar aggregate ratios can be designed with the same aggregate stockpiles. For the specific stockpiles used in the verification, the AMIDO mix design resulted in a 53-cent/ton reduction in aggregate cost. This work improves the state of the art in asphalt mix design for dense-graded mixes and could be modified for other mixes.