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Recycled aggregate (RA) from construction and demolition waste is traditionally used for the manufacture of concrete for different applications. Due primarily to high water content required by RA, the quality of the concrete is determined by the amount of replacement RA. The aim of this study is to determine if RA pre-soaking enhances the properties of pre-cast concrete for street furniture, with low mechanical and structural requirements, in which 100% of the coarse fraction is replaced. The results of physical and mechanical tests performed on concrete specimens in which the RA was pre-soaked using five different methods applied are compared with a reference concrete sample and a concrete sample made with non-pre-soaked RA. The results show that non-pre-soaked RA offers improved physical-mechanical properties for pre-cast concrete, except for the workability; problems arising from poorer workability could be improved with the use of plasticizers, which can be easily included in the production process. RESUMEN: Estudio de las ventajas potenciales del premojado en las propiedades del hormigón prefabricado con árido reciclado grueso.El árido reciclado (AR) procedente de residuos de construcción y demolición se utiliza tradicionalmente en la elaboración de hormigón para diferentes aplicaciones. Debido principalmente al mayor contenido en agua requerido por el AR, la calidad del hormigón está determinada por la cantidad de AR reemplazado. El objetivo de este estudio es determinar si el AR premojado mejora las propiedades del hormigón prefabricado para mobiliario urbano, con bajas exigencias mecánicas y estructurales, en el que se sustituye el 100% de la fracción gruesa. Los resultados de los ensayos físicos y mecánicos realizados sobre muestras de hormigón en las cuales el AR se ha premojado usando cinco métodos diferentes se han comparado con una muestra de hormigón de referencia y una muestra de hormigón fabricada con AR no premojado. Los resultados muestran que el AR no premojado proporciona propiedades físico-mecánicas mejoradas en el hormigón prefabricado, a excepción de la trabajabilidad; los problemas derivados de una deficiente trabajabilidad pueden ser fácilmente corregidos con la incorporación de plastificantes en el proceso de fabricación.

Recycled concrete has a microstructure more complex than natural concrete, as it includes new interfacial transition zones, the quality of which is conditioned by the state of humidity of the aggregates used, which in turn will affect the final properties of the concrete. Bearing in mind the greater absorption capacity of recycled aggregates, it is important to improve its properties by means of a treatment method that is capable of reducing the negative effects that this may produce in the new concrete. Therefore, the influence of the pre-soaking method of recycled aggregates on the formation of the microstructure of concretes manufactured with these aggregates is analysed, to determine which treatment is the most effective for the production of concretes for non-structural use. The results show that the microstructure of the evaluated concretes differs according to the treatment method used, the most optimal method being one that uses aggregates without pre-soaking.

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Granada and its metropolitan area lie on the eastern edge of a basin where the foothills rise into the adjacent Sierra Nevada (3,482 m). On the west the valley is bordered by several faulted, Quaternary-age alluvial fans and by dissected terraces of the Genil River. Landscape evolution from about Tortonian to Pleistocene time is reflected by relict Quaternary glaciers preserved on a deeply eroded lower Paleozoic terrain and by terrace remnants and channels resulting from rapid Late Pleistocene and Holocene fluvial incision. This particular geological, geomorphic, and active tectonic setting, combined with a Mediterranean climate under continental influence, and the rapid urban development in the last 60 years have increased exposure to several natural hazards. Urban expansion has increased flash-flood and mass-wasting vulnerability, and seismic risk is similarly increasing with the 1884 Andalusian Earthquake (M 6.3), reflecting the last of several large, ,500-year recurrence temblors that have affected the area since at least Roman times. Modern Granada and its metropolitan area, with about a half million inhabitants, are currently increasingly challenged by the highest levels of exposure to natural hazards, by strain on traditional society resulting from adapting to the changes produced by the three decades since the advent of democracy (1978) and by the consequences of the deep economic crisis.