Fray Symposium - Physical And Chemical-Mineralogical Characterization Of Fine Recycled Aggregates From Construction And Demolition Waste
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2011-Sustainable Industrial Processing Summit
SIPS2011 Volume 4: Materials Recycling, Silicon Photovoltaic Cells, Boron & Borates

Editors:Florian K
Publisher:Flogen Star OUTREACH
Publication Year:2012
Pages:754 pages
ISBN:978-0-9879917-3-7
ISSN:2291-1227 (Metals and Materials Processing in a Clean Environment Series)

    Physical And Chemical-Mineralogical Characterization Of Fine Recycled Aggregates From Construction And Demolition Waste

    Rodrigues Fernando1; M. Teresa Carvalho1; Manuel Francisco Pereira1; Luis Evangelista2; Jorge de Brito1;
    1IST, Lisbon, Portugal; 2ISEL, Lisbon, Portugal;
    Type of Paper: Regular
    Id Paper: 187
    Topic: 12

    Abstract:

    Recycled aggregates from construction and demolition waste (CDW) are commonly classified in coarse (CRA) and fine (FRA) fractions. Unlike CRA, which are now widely used in different applications including concrete, FRA (minus 4 mm fraction) are used as low-value products (for roads, landscaping and landfilling). One of the main reasons for this is the poor knowledge of their properties which prevents their application in added-value products such as concrete.The development of a methodology to classify FRA aiming at their application in different applications relies on the physical and chemical-mineralogical characterization that is conditioned by the composition of the CDW and by the processing they were subjected to.This paper describes the experimental work carried out aiming at the characterization of this fraction of recycled aggregates and of its influence on the properties commonly used to predict concrete behavior.For this purpose, samples of 7 Portuguese CDW recycling plants were collected. The criteria to choose the plants were the geographical location and the type of CDW processing at the recycling plant. The former was due to the geological environment where the materials used in the construction were collected and to the building techniques employed, because they are most probably related with the composition of CDW and the resulting aggregates. The CDW processing diagram, equipment type and parameter settings may also affect the physical and the physical aggregate properties.The particle size analysis of each FRA was carried out and the +1 mm fraction was manually separated in different materials (e.g. aggregates, wood, plastics) for composition evaluation. The inert fraction was grinded and dissolved in HCl for carbonates and other soluble minerals quantification. Then, a chemical-mineralogical characterization of the remaining sample by means of X-ray fluorescence and X-ray diffractometry was made.Finally, the physical properties of the aggregates that are commonly used to predict concrete behavior sucha as bulk density, water absorption and voids percentage were determined. The relationship between these and the physical and chemical-mineralogical characteristics was obtained leading to classification of FRA in different categories.

    Keywords:

    CDW, Recycling, Recycled Aggregates, Mineralogy, Physical and chemical characterization

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    Cite this article as:

    Fernando R, Carvalho M, Pereira M, Evangelista L, de Brito J. Physical And Chemical-Mineralogical Characterization Of Fine Recycled Aggregates From Construction And Demolition Waste. In: Florian K, editors. Sustainable Industrial Processing Summit SIPS2011 Volume 4: Materials Recycling, Silicon Photovoltaic Cells, Boron & Borates. Volume 4. Montreal(Canada): FLOGEN Star Outreach;2012. p..