Photocatalytic pavements with epoxy-bonded TiO2-containing spreading material

• A new surface treatment method to achieve photocatalytic asphalt pavement was developed.
• Custom-designed TiO2-cement mortar was pulverized and bonded to asphalt pavement surface by epoxy.
• Durable NOx degradation efficiency was achieved using the new method.
• The new method also provides asphalt pavement excellent skid resistance during its life time.

Titanium dioxide (TiO2) is a photocatalyst which can accelerate the oxidation of nitrogen oxides (NOx) and other pollutants under ultraviolet (UV) radiation. In this study, a new method to coat TiO2 onto asphalt pavements was developed with the aim to enhance the NOx decomposition efficiency and durability of the coating material for asphalt pavements. In this method, pulverized TiO2-cement mortar is used as the spreading material, which is bonded to asphalt pavement surface by epoxy resin. The composition of the TiO2-cement mortar was optimized in terms of its mechanical properties. The long-term NOx degradation efficiency, abrasion resistance, and skid resistance of the spreading material were measured after it was subjected to 300 min polishing by the advanced Aachen Polishing Machine (APM). It was concluded that durable NOx degradation efficiency can be achieved by the developed method and the method is feasible for practical implementation.