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Leaching issues in recycled                                 12


           aggregate concrete

           Manuel Cabrera, Adela Pe ´rez Galvı´n and Francisco Agrela
           Construction Engineering Area, University of Cordoba, Leonardo Da Vinci Building,
           Rabanales Campus, Cordoba, Spain






           12.1    Environmental risks of recycled aggregate concrete

           Recycled aggregate concrete is defined as concrete manufactured with waste materials
           in order to reduce the negative environmental impact that results from the manufactur-
           ing process of cement, achieving a more sustainable product. For that purpose, scien-
           tific investigations have evaluated a wide variety of waste materials that can be
           incorporated to the concrete mixture: recycled aggregate from construction and demoli-
           tion waste (CDW, the most extensively researched material), glass, coal fly ash, bio-
           mass bottom ash, plastic, tyres, volcanic ash, iron and steel slag or foundry sand.
              Regardless of the physical and mechanical properties of the waste materials used
           in the concrete, it is essential to assess their pollutant potential due to the presence
           of hazardous compounds that may be released to the environment. The release level
           of hazardous chemical elements must be evaluated and their content in the recycled
           aggregate concrete cautiously controlled. Leaching tests have proved to be a useful
           analytical tool.


           12.1.1 Legal regulations for environmental assessment of
                   recycled aggregate concrete

           Since 2005, the European Commission has supported environmental activities and
           initiatives with the aim of the enforcement of the European policies of waste con-
           trol at national levels for each Member State. The main objective of these policies
           has been focused on different aspects as: optimising waste management and the
           involved agents, increase research and innovation studies in waste recycling, maxi-
           mising reusing and recycling and minimising landfilling. In that sense, the linear
           economy (materials used to manufacture a product and converted into waste after
           its use) can be definitely replaced by a circular economy (in which any waste
           becomes another’s raw material after its recycling and management).
              To achieve the implementation of a circular economy at all levels, it is essential
           to perform an evaluation of the environmental risks produced during the extraction
           of raw materials and natural resources, throughout the entire life cycle of the
           manufacturing process of a product, or during the phase of elimination or disposal
           of residues.
           New Trends in Eco-efficient and Recycled Concrete. DOI: https://doi.org/10.1016/B978-0-08-102480-5.00012-9
           © 2019 Elsevier Ltd. All rights reserved.
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