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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
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