The influence of Aggregate Gradation Designed by Bailey Method on the Volumetric Properties of Asphalt Mixture Prepared by Superpave Design Method

摘要

Asphalt mixture contains approximately 90-95% of mineral-aggregate by weight and the gradation of aggregate considers one of the key properties in the aggregate blend. Therefore , the aggregate gradation influence on the asphalt mixtures performance is a considerable problem. Mid-limit gradation curve is recognized as the most proper gradation, but does not all the time produce preferable results. The Bailey method provides a means for designing of aggregate gradation in asphalt mixtures, taking into consideration the volumetric aggregate blend characteristics , in order that asphalt mixtures exhibited a strong-skeleton for high stability and appropriate VMA for good durability. Bailey method calculations are time consuming. Therefore , Excel spreadsheet is developed in order to save time and decrease the calculation errors.Eight aggregate blends , which involve fine and coarse graded mixtures with four blends for each of the two types of mixtures , are designed for the evaluation of Bailey method and the optimum-asphalt-content is identified for each-gradation. The tests utilized for identifying the volumetric asphalt mix properties are conducted to find the effect Bailey parameter on the volumetric asphalt mix properties.