A byproduct of changes in bitumen quality is the trend for engineers to formulate asphalt mixes using a balanced mix design approach. This relatively new method accounts for variable bitumen specifications while prioritizing adherence to performance standards. Balanced mix design also allowed for incorporation of additives that can enhance the functional properties of a mix to improve performance outcomes. Rather than relying solely on binder or aggregate specifications to meet performance standards, all aspects of the mix (binder, aggregate, modifiers, and additives) are formulated to balance factors such as fatigue, rutting, and cracking characteristics.
Implementation of Balanced Mix Design for Asphalt Mixtures
Mix design engineers are constantly tasked with determining the right ratios of aggregate and binder to develop asphalt mixtures that will meet performance requirements. Traditionally, mix designs have employed volumetric analysis relying on the evaluation of compacted samples to determine properties such as air voids and voids in mineral aggregate, among others. For instance, the Marshall method includes tests [...]
