Towards highly sustainable asphalt mixtures using RAP and ceramic waste

The European Union promotes transitioning to a circular economy, prioritizing waste management as a key element of sustainable development. In this context, this study evaluates the structural performance of asphalt mixtures incorporating Reclaimed Asphalt Pavement (RAP) and ceramic waste, focusing on maximizing recycled material usage while meeting Spanish pavement standards for low-volume roads. While recycled materials in asphalt mixtures are widely studied, limited research has addressed the combined use of RAP and ceramic waste. Three sustainable AC16 S asphalt mixtures were designed with recycled content ranging from 85 % to 100 % and evaluated through water sensitivity, wheel tracking, stiffness, and resistance to fatigue tests. The results indicate that the C50R50 mixture, comprising 50 % RAP and 50 % ceramic waste, achieves performance comparable to conventional asphalt mixtures made with natural aggregates. It meets all Spanish standards for low- and medium-volume roads, demonstrating satisfactory stiffness (approximately 7000 MPa) and resistance to fatigue, reaching 80 % of the endurance of conventional mixtures. Conversely, the C100 mixture (100 % ceramic waste) exhibited reduced stiffness, water sensitivity, and workability, limiting its applicability. The C50R50 mixture showed acceptable deformation indices and superior workability, making it also suitable for urban pavements and micromobility infrastructure, including bike lanes. The C35R50A15 mixture (50 % RAP, 35 % ceramic waste, and 15 % limestone aggregate) achieved marginal compliance, suggesting potential for similar applications. These results demonstrate the feasibility of sustainable asphalt mixtures to meet performance standards, offering an environmentally friendly alternative for road construction and maintenance in low- and medium-traffic applications. • Three asphalt mixtures made with RAP and ceramic waste were structurally assessed. • The C50R50 and C35R50A15 mixtures meet standards for low-volume roads. • The C50R50 mixture achieves stiffness comparable to that of conventional asphalt. • The C50R50 mixture yields 80 % resistance to fatigue of conventional mixtures. • Increased ceramic waste content reduces water sensitivity and workability.