Porous concrete for pedestrian pavements
Changes in weather patterns directly impact urban transport infrastructures. The increase in temperature and the ongoing precipitation changes should be handled and managed more frequently. In urban areas, most of the soil is impermeable and water hardly infiltrates into the subsoil. Permeable pavement is a technology that helps mitigate the effects of urban heat islands and surface impermeabilization. Porous concrete for pedestrian pavements ensures good structural, functional, and environmental performances. A pervious concrete mix differs from a conventional one in terms of the gradation of aggregates, namely, a lack of fine aggregates. The material porosity (on average 20%) causes compressive and flexural strengths lower than those of traditional concrete. The material is suitable for low-load pavements where the passage of motorized vehicles is forbidden or occasional. The pavement can be laid either monolithically or modularly, using two operating systems: returning water to underground aquifers and reducing runoff. The latter is the most frequently adopted in urban areas, where pedestrian and interdicted to motorized vehicle areas form a continuous and distributed network. In a common urban quarter, where 80% of the surface is impermeable, porous concrete pavements could cover up to 6% of the surface and provide architectural and aesthetic value for the environment.