Design and performance of a warm high-modulus asphalt concrete

Undoubtedly, the road system around the world, if effective, is one of the keys to economic growth. However, the asphalt production in particular provokes a giant environmental impact. Among the several ways that have been researched to minimize these negative consequences, warm mix asphalt concrete has emerged, giving a response to the need to reduce energy costs and emissions of greenhouse gases (GHG) caused by hot mix asphalt plants. This is particularly important in the case of high-modulus asphalt concrete (HMAC), because these mixtures are produced from hard bitumens that need high temperatures to achieve the required viscosity and ensure the proper coating of the aggregates, the workability and compactability of the mixture. Higher heating temperatures results in higher energy consumption and increased environmental impacts. This issue is very important in hot mix asphalt (HMA) in general, as discussed in several studies, but it is even more important in the case of HMAC. On the other hand, reducing the manufacturing temperature, while keeping the quality of the final mixture, presents a greater challenge. A study was conducted to verify if the performance of a high-modulus asphalt concrete, produced at temperatures lower than the conventional ones, would be compromised by the introduction of a chemical additive, compared to a standard mix.