Influence of clogging on the hydrologic performance of a double layer porous asphalt

ABSTRACT

Nowadays, the increasing urbanisation and the effect of climate change in cities has been a constant concern. In particular, the floods cause a significant increase in surface runoff, mostly on roads and parking areas. As an alternative to asphalt pavements, usually used in these areas, permeable pavements have been developed with Porous Asphalt (PA). These pavements allow the infiltration of water from the surface to the ground due to the high void content of the PA, thus reducing the surface runoff and increasing recharge of groundwater. Over the years, the infiltration capacity of the mixtures decreases with the clogging by sediments from the vehicles themselves and/or from the local environment. In order to mitigate this effect, a Double Layer Porous Asphalt (DLPA) was developed. This research intends to deepen the knowledge about the influence of the clogging of a DLPA, with respect to the infiltration capacity, since it is an essential theme in the pavements lifespan and that needs to be developed. This study considered different evaluation phases of the infiltration capacity with two clogging cycles (500 and 1000 g/m2). The materials used were: sand, region soil, and rubber waste. The infiltration capacity test was performed in different phases after a rainfall event of 100 mm/h with a rainfall simulator developed for this purpose. Furthermore, the permeability test with the falling head permeameter was carried out in parallel, obtaining outflow times for each clogging phase and subsequent maintenance phase. The research concluded that DLPA has a high infiltration capacity after the first clogging cycle in both performed tests. In the second clogging cycle, the results show that the infiltration decreased due to the partial filling of the pores, mainly, for the rubber-filled DLPA. The type of clogging material influences the infiltration capacity, nevertheless partially recovered after simple maintenance was performed.

KEYWORDS:

• Infiltration capacity
• clogging
• porous asphalt
• maintenance
• rainfall simulator
• falling head permeameter

Acknowledgements

This work is supported with Portuguese national funds by FCT - Foundation for Science and Technology within the UID/ECI/04082/2013 project. The authors are grateful for the supply of rubber waste granules by Biogoma company.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Márcia Lopes Afonso http://orcid.org/0000-0002-1911-891X

Additional information

Funding

This work is supported with Portuguese national funds by FCT - Foundation for Science and Technology within the [grant number UID/ECI/04082/2013] project.