Pervious (lean) concrete for sustainable road pavements: results of the Belgian Be-Drain project

With the impacts of climate change, we are increasingly affected by major flooding events, also in Belgium, against which action has to be taken urgently enabling more infiltration and buffering of rain water. To this effect, porous lean concrete is already known and applied for a long time in Belgium as a base layer material, especially for block paving. Nonetheless, there is still a demand for a more representative compaction method in the lab, in the framework of certification of these mixtures for base layers. On the other hand, due to the need for more integral stormwater management, more recently there is also increased interest & demand for water permeable pavements among which cast-in-place pervious concrete. However, currently no technical guidelines nor any performance requirements exist in the Belgian road sector for the application of porous concrete for road pavements. Hence, to tackle both topics the Belgian Road Research Centre conducted a national prenormative research, called Be-Drain, in collaboration with the national cement research centre CRIC-OCCN); the Be-Drain project’s principal objectives were to provide: Technical guidelines, performance requirements and adapted testing methods for pervious (draining) concrete mixes as a function of application (top or base layer), compaction methods and functional requirements (e.g. freeze-thaw resistance); Recommendations for Belgian standard tender specifications and possible normalization. In this paper we aim to summarize the main findings of the Belgian Be-Drain project with a view to further develop pervious (lean) concrete as a promising solution for sustainable water management in urban areas.