<p>Asphalt pavements are highly sensitive to temperature fluctuations, which often lead to thermal-related distresses such as rutting and cracking. This study explores the incorporation of Phase Change Materials (PCMs) into asphalt mixtures as a thermal regulation strategy by utilizing two types of porous aggregates—scoria and steel slag—as PCM carriers. The aggregates were saturated with PCM using an immersion method, and a novel pozzolanic slurry treatment was applied to reduce PCM leakage during asphalt mixing. The mechanical and thermal performance of the resulting asphalt mixtures was evaluated through Marshall stability tests, moisture susceptibility (modified Lottman) tests, rutting resistance assessments, and solar radiation simulation experiments. Results showed that scoria exhibited higher PCM absorption (up to 23%) than steel slag (up to 5%) due to its higher porosity. However, mixtures incorporating PCM-filled steel slag demonstrated superior thermal regulation and mechanical performance. The pozzolanic treatment effectively reduced PCM leakage by approximately 20%, contributing to improved stability and durability of the asphalt mixtures. Thermal testing revealed that PCM-modified mixtures exhibited surface temperatures up to 8&#xa0;°C lower than control samples, with delayed heat penetration. In terms of rutting performance, steel slag-based mixtures showed the greatest resistance under high-temperature conditions. Overall, the findings indicate that treated porous aggregates filled with PCM can enhance the thermal and mechanical behavior of asphalt mixtures. In particular, steel slag aggregates with lower PCM content provided a more balanced and efficient solution, offering promise for more resilient and temperature-stable pavements.</p>