A review of design, construction, and performance of permeable asphalt mixes in rainy countries: case of Colombia

Abstract

Colombia is located in a tropical region, characterized by a predominant humid rainforest climate. In rainy seasons, traffic accidents are more likely to occur due to the wet condition of the pavement. To overcome this situation, permeable asphalt mixes (PAM) represent a feasible alternative to evacuate runoff water from the surface asphalt layer. PAM are discontinuously-graded asphalt mixes with a high content of air voids (AV) allowing a surface macrotexture and a high hydraulic conductivity attaining safer roads. Over the last decade, road concessionaires -private sector firms that build and operate roads in Colombia for periods consisting of twenty to thirty years- have developed projects employing PAM as top layers over primary-level roads (Inter-state). In consequence, the gained experiences using PAM are varied; some agencies have reported satisfactory behavior, whereas others have reported raveling as the primary distress at the end of their life cycle and then discontinuing its use. This paper aims at providing an overview of the design, construction, and performance of PAM in rainy countries. After explaining the current design practice in Colombia, three case-studies are reported and comprehensively analyzed, considering functionality and durability. From these analyses and compared to abroad experiences, some insights are given to improve the current practice based on performance criteria particularly for rainy countries. At the end, this paper represents a contribution towards the state-of-practice and implementation of PAM in countries with heavy rainfall regimes.