Upcycling of Sewage Sludge Ash into Foaming Warm Mix Asphalt Additive for Sustainable Asphalt Pavement Construction

Waste recycling/upcycling has become an important topic in highway and pavement engineering, because of its significant economic and environmental benefits. This presentation will start with a brief introduction to the green technologies developed in Hong Kong to recycle various types of wastes, such as reclaimed asphalt pavement, waste tyre rubber, and waste plastics, into pavement. Then, a recent study on converting sewage sludge ash into zeolite-based foaming warm mix asphalt additive, which can reduce the construction temperature of asphalt pavement by at least 20 ^oC without compromising its mechanical performance, will be presented. In the end, some remarks and discussions on recycling wastes into pavement will be provided.