In the European Union (EU), the incineration of wood biomass and sewage sludge yields approximately 25 million tons of waste residue annually. These residues currently present a significant challenge within the construction industry, as they are either directed towards low-value applications or left unused. Challenges such as limited public awareness of safety and environmental implications, inconsistencies in legislation, and market hesitation impede their widespread adoption. In light of climate change, circular economy principles, and stringent environmental regulations, the construction sector requires innovation to shift its status from surplus to critical need. The revised Construction Products Regulation (CPR) acknowledges this necessity and mandates the prioritized use of recycled materials. Within this context, the central focus of this paper is on an illustrative case study outlining the development and implementation of sewage sludge ash (SSA) in the pilot-scale production of precast semi-dry concrete pavement elements. Beginning with the a priori characterisation of incineration waste residues, the study evaluates the feasibility of utilizing these materials as a substitute for sand in large-scale concrete batching plants. Mechanical properties and durability are assessed in alignment with the technical requirements of precast concrete manufacturers. Beyond engineering considerations, the ecological significance is underscored by addressing the leaching of heavy metals from concrete composites containing waste ash, with a particular emphasis on environmental safety.

low-carbon pavement solutions, incineration ashes, environmental impact, sustainability, circular concepts