Porous Concrete (PC) pavements have been gaining a lot of attention in recent years because of the many advantages they can provide, especially in urban areas because they are easy to lay and capable of mitigating the problems caused by conventional roads. For this reason, PC pavements have been recognized as one of the best solutions to reduce water and air environmental impacts, as well as to increase driver safety. Nevertheless, their use is still limited, since there are not enough studies addressing them comprehensively, mainly because of the lack of awareness about all their potential benefits. Therefore, this paper reviews the main properties that PC mixtures can provide for designing multifunctional and sustainable pavements. To this end, the investigations undertaken during the last decade (2009-2018) in this topic were analyzed in detail, identifying the regions where they are being most widely studied, analyzing and predicting their future potential developments. Results revealed that mechanical and hydraulic capacity are the two main properties studied in PC pavements. In addition, a predicted growth for 2019-2030 of 2.51% (4.29 PC publications per year) is expected.

Alternative materials to replace cement in pavements have recently been widely studied with the purpose of decreasing the environmental impacts that the construction industry generates. In this context, the implementation of sustainable urban drainage systems has grown, especially with porous pavements, with the intention to reduce water and environmental impacts. In the present investigation, the addition of alternative materials to minimize the use of cement in porous concrete pavements is evaluated. Starting from a partial substitution of Portland cement with metakaolin, experimental geopolymer concretes were produced with metakaolin and waste basalt powder according to several dosages. Two sets of mixtures were analyzed to evaluate the Porous Concrete Design (PCD) methodology for porous concrete mixtures with alternative materials. A deep analysis was proposed for the evaluation of the mechanical and volumetric properties of the mixtures. Results demonstrated that replacing 5% of cement with metakaolin can increase both permeability and indirect tensile strength. Geopolymer mixtures can achieve permeability significantly higher than the traditional porous concrete, but this decreases their indirect tensile strength. However, considering the promising results, an adjustment in the mix design of the geopolymer mixtures could increase their mechanical properties without negatively affecting the porosity, making these materials a suitable alternative to traditional porous cement concrete, and a solution to be used in urban pavements.

Despite the number of environmental advantages that porous concrete (PC) pavements can provide, they are mainly used in light-traffic roads, parking lots and sidewalks due to their low mechanical strength. This research focuses on the common additives employed in PC pavements, according to a literature review, with the aim of increasing their mechanical strength while maintaining an acceptable infiltration capacity. The results demonstrated that the combination of superplasticizers and air-entraining additives can provide indirect tensile strength values over 2.50 MPa, with an infiltration capacity over 0.40 cm/s. In addition, polypropylene fibers were seen to provide very good safety properties, preserving some structural integrity in the case of failure. All mixtures studied obtained outstanding skid resistance results under both dry and wet conditions.

Many cities around the world are handling many problems derived from urbanization, resulting in an uncontrolled growth of cities. Moreover, Climate Change effects are affecting all countries and specially cities. In this context, urban drainage and paving strategies demand a bigger economical investment to avoid a great impact in citizens quality of life, and in the environment. The main objective of this research is to contribute, in an innovative way, with the construction of concrete urban pavements by studying, quantifying and trying to join together a series of characteristics and benefits that are analyzed nowadays, but in a separately way. Trying to achieve an integrated pavement, with resilient properties (adapted to Climate Change) and more sustainable (economically, socially and environmentally).

Research has been done to obtain a Porous Concrete (PC) mixture capable of bearing heavy traffic loads while maintaining sufficient air voids (AV) to percolate water into the ground. This research aims to establish several design parameters in PC mixture dosage in order to generate a multicriteria methodology that helps to obtain a final product, which is beneficial for both citizens and environment. Compression strength, indirect tensile strength, permeability, skid resistance, and stiffness modulus were evaluated, employing different aggregate gradations (AG), water to cement (w/c) and sand to cement (s/c) ratios, designing with the Porous Concrete Design (PCD) methodology. Results demonstrated that the right addition of sand and AG can improve mechanical capacity by around 10% and permeability rates by around 25%. This investigation provides a starting point for the use of additives in PC mixtures that helps to bring multifunctional properties such as heat island mitigation, air purification (photo-catalysis) and noise reduction, among others.