This thesis evaluates the leaching characteristics and environmental impacts of conventional and rubberized porous asphalt mixtures subjected to tidal flooding conditions. Given the increasing vulnerability of coastal infrastructures to tidal floods exacerbated by climate change, the research investigates explicitly the release behavior of metals, metalloids, and anions from both crumb rubber-modified and conventional porous asphalt immersed in tap water and seawater. The study aims to provide insights into the environmental implications of utilizing crumb rubber, derived from recycled tires, in porous asphalt formulations, balancing its mechanical benefits against potential environmental risks.

Through systematic laboratory experiments, leachates from compacted cylindrical asphalt samples were collected and analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES) for metals and Ion Chromatography (IC) for anions. The results demonstrate that crumb rubber significantly affects the leaching behavior of asphalt mixtures by acting as an adsorbent for several contaminants. Thus, generally reducing their leaching potential compared to conventional porous asphalt. However, elevated concentrations of certain elements, such as zinc, aluminum, and magnesium, originating from the crumb rubber itself, were observed, highlighting the complexity of the environmental behavior of these mixtures.

The research identifies critical differences in leachate release patterns between two different conditioning methods, with an initial rapid release of surface-bound contaminants followed by slower diffusion-controlled processes. Elements such as nickel and cadmium displayed unique delayed release behaviors, suggesting potential long-term environmental implications. Additionally, the study highlights the significant role of material composition, particularly tire-derived crumb rubber and structural additives, in influencing the leaching profiles.

The environmental risk assessment performed using the Heavy Metal Pollution Index (HPI) further emphasizes that crumb rubber-modified porous asphalt generally presents lower environmental risks compared to conventional mixtures. Nevertheless, specific metals and ions exceed regulatory thresholds, underscoring the importance of considering local environmental standards in the implementation
of these materials.

Overall, this research contributes valuable knowledge regarding the sustainable application of crumb rubber-modified porous asphalt in coastal regions. Recommendations for future studies include the investigation of long-term leachate dynamics under diverse environmental conditions and the exploration of effective mitigation strategies to enhance the ecological compatibility of asphalt pavements.