Centre of Materials and Building Technologies

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Organizational Unit

Publications

Towards Rural Land Use: Challenges for Oversizing Urban Perimeters in Shrinking Towns

Publication . Sá, João Paulo Costa e; Virtudes, Ana L.

This article, based on the literature review, aims to study the challenges of the urban dispersion and oversizing of urban perimeters, in the cases where the towns are shrinking or spreading to the rural land-use. It is focused on the case of Portugal where during the last decades there was an escaping to the big cities alongside to the sea (Atlantic and Mediterranean) shore. In the Interior part of the country, which means near to the border with Spain, several towns are shrinking, despite their huge urban perimeters, proposed by the municipal master plans, since the middle of the nineties. Consequently, these urban perimeters are nowadays oversizing, with empty buildings and non-urbanized areas. At the same time, the social patterns of occupation of this territory have changed significantly, moving from a society with signs of rurality to an urban realm, understood not only in territorial terms but also regarding the current lifestyle. This deep changing has occurred not only in urbanistic terms but also in the economic, cultural and social organizations of the country, under a movement that corresponds to a decline of the small urban settlements in rural areas, far away from the cosmopolitan strip of land nearby the sea, in between the capital city, Lisbon and the second one Oporto. These transformations were not driven by any significant public policy for landuse actions. On the contrary, the production of urban areas, supporting the new model of economic and social development was largely left to the initiative of economic and social private agents and land owners. These agents were the leading responsible for the new urban developments and housing. In this sense, this research aims to present some strategies for the short time period regarding the devolution of urban areas to rural land use. In this sense, the next steps of spatial planning policies, under the role of local authorities (the 308 municipalities including Madeira and Azores islands, plus the continental part of the country), which are their main promoters, will be motivated by the need of advocating the swap of many urban areas towards the rural land use, shrinking many existent urban perimeters in depressed territories. How will the non-urbanized spaces, included in the urban perimeters, twenty years ago, by the pivotal instrument of spatial planning in Portugal, the Municipal Master Plans turn back to the rural land-use, losing their market value? This is the base of the challenges ahead, analysed in this article.

2017Journal article

Open access

Characterization of the Skid Resistance and Mean Texture Depth in a Permeable Asphalt Pavement

Publication . Afonso, Márcia Isabel Lopes; Almeida, Marisa S. Dinis; Fael, Cristina Maria Sena

Road pavements need a deep characterization of the surface layer, with which the vehicles have direct contact and, therefore, must provide security to the users. The use of permeable asphalt pavements (PAP) with porous layers has provide obvious advantages in reducing runoff and the rainwater infiltration into the soil or for storage. However, the study of the interaction between the pavement surface layer and the tire rubber requires additional tests in terms of texture and friction, since they are important parameters for the design, construction, management, maintenance and roads safety. Considering the application of a PAP in a parking lot, the study objective was to characterize in the field the pavement surface in terms of mean texture depth (MTD) and skid resistance (Pendulum test value, PTV). The methods used were the volumetric technique by the patch test and the pendulum test, according to EN 13036-1 and EN 13036-4, respectively. The double layer porous asphalt (DLPA) at the surface is characterized by having a structure with high voids content that led to results of clearly rougher macrotexture and good skid resistance. The normalized limit values were met, however, a very strong correlation between MTD and PTV was not observed. A comparison was also made with porous surfaces of other studies and it was found that porous asphalt has a good behaviour at the start of construction which may tend to improve in the long term. From the study, it is concluded that the PAP presents good performance of the surface layer, providing road safety to users.

2019-02Conference object

Open access