Influence of chemical pore-clearing method on infiltration rates of pervious asphalt concrete pavement

ABSTRACT

Pervious asphalt concrete (PAC) pavement is an environmentally friendly type of pavement due to its highly porous structure. However, with the increase in the service life of PAC, small substances such as damaged rubber particles, industrial dust, sand, and grease collected in rainwater infiltrate the voids of PAC so that it loses its original pervious structure and functions. In order to explore the effects of chemical pore-clearing methods on the infiltration rate of blocked PAC pores in the present study, chemical agents such as sodium hydroxide solution (H₂O₂) and hydrogen peroxide (NaOH) solution were used to rinse the voids in PAC specimens obtained from field sampling and laboratory preparation. The effectiveness of different chemical pore-clearing methods in restoring the permeability and stability of PAC was evaluated by water infiltration rate measurements, Cantabro abrasion tests, and CT scanning. The results showed that the capability of H₂O₂ solution to restore PAC porosity was greater than that of tap water and NaOH solution, especially when the H₂O₂ content in the solution was 6%. In addition, the decomposition products of H₂O₂ are oxygen and water, which are environmentally friendly products, this method proved highly effective in preventing groundwater contamination from pavement-cleansing chemical solutions.

Keywords
Pervious asphalt concrete; Chemical pore-clearing methods; Infiltration rate; Environmental product