Application of a Five-Step Laboratory Procedure to Select WMA Chemical Additives

Although several technologies have been tested and are being used worldwide, reducing operating temperatures for asphalt concrete remains a challenging task for road industry designers. Every warm mix asphalt (WMA) technology, including chemical additives, is characterized by specific peculiarities that make its effectiveness dependent on the working conditions, such as mix plant facilities, asphalt concrete type, reclaimed asphalt content, climatic region, or traffic volume. The primary aim of this research is to evaluate the effectiveness and role of chemical additives in reducing the operating temperatures of asphalt concrete through a reliable and cost-effective testing procedure. In addition to assessing effectiveness and identifying the type of additive, the experimental procedure takes into account the most commonly used parameters in the asphalt concrete specifications to ensure compliance with fundamental requirements for full-scale application. The applied laboratory process includes chemical analysis, viscosity evaluation, adhesion assessment, workability investigation, and resistance validation. The findings will contribute to optimizing asphalt mixtures, minimizing environmental impact, and advancing sustainable road construction technologies.