Progress of Recycling in the Built Environment

Final report of the RILEM Technical Committee 217-PRE

herausgegeben von: Enric Vázquez

Verlag: Springer Netherlands

Buchreihe : RILEM State-of-the-Art Reports

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik" , Springer Professional "Wirtschaft"

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Über dieses Buch

This report is a useful tool for countries starting to recycle aggregates or construction and demolition waste.

It contains the latest developments in this field, introduces a completely new approach to the procedure of proportioning concrete mixtures with recycled aggregate, references recent publications, opinions and discrepancies in relation to the durability of recycled concrete, such as freeze-thaw standards, studies of chloride penetration and diffusion, and sulfate attacks, the use of the fine fraction <4mm, quality assurance of concrete recycled aggregate, sustainability and recycling construction waste and global impact assessment of urban renewal based on sustainable recycling strategies for construction and demolition waste.

This volume will be of interest to recyclers, researchers and consumers.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction and Activities

Abstract

This report is the result of the work done by the members of the TC and collaborators, discussed in nine meetings and the rich contributions of the Symposium of Sao Paulo 2008, the Sao Paulo International RILEM Conference Progress of Recycling in the Built Environment 2009 and Shanghai RILEM 2nd International Conference on Waste Engineering and Management 2010.This events were promoted by members of the TC 217 and co sponsored by RILEM.

Enric Vázquez

Chapter 2. Construction and Demolition Waste Recycling in a Broader Environmental Perspective

Abstract

The scope of this chapter is to analyse the prospects for recycling the mineral fraction of construction and demolition wastes as aggregates within the frame of sustainable construction, and to identify research needs. Sustainable construction is defined by life-cycle evaluation of environmental, economic and social aspects, and is dependent not only from production processes but also from local constraints and market alternatives. Environmental performance of recycling construction and demolition waste must be evaluated cradle-to-grave, using multi-criteria life-cycle assessment tools. Economic performance depends on life cycle cost and has to consider externalities. Social assessment can be done using the new social life cycle assessment methodology. The flows of aggregates and construction waste in the near future, as well as the presence of informal activities in the supply chain, have strong influence on the sustainability in every location. Attractiveness of recycling CDW as aggregates will depend of local environmental, social and economic conditions. Examples of life cycle thinking applied to CDW aggregates are given and research needs discussed.

Enric Vázquez

Chapter 3. Overview Regarding Construction and Demolition Waste in Several Countries

Abstract

The objective of this chapter is to collect the data of advancements, achievements, problems and solutions most representative of the various countries. Thereby, each country can learn from examples and underpin a pedagogy for the effective implementation of recycling. A short review of the history of recycling of construction and demolition waste is presented. Market situation, applications, standards and characteristics of the production in countries are described.

Enric Vázquez

Chapter 4. Recycled Concrete

Abstract

A new approach to the proportioning of concrete mixtures with recycled aggregate is presented. This procedure requires less cement, which makes it more economical and environmentally attractive. Recent publications, opinions and discrepancies in relation to the durability of recycled concrete, such as freeze-thaw standards, studies of chloride penetration and diffusion, and sulfate attacks, are examined. The removal of gypsum constituents from recycled aggregates during their processing seems indispensable. This can be achieved with jigging machines, in which asymmetrical jig stroke diagrams can be implemented. Another effective technique for reducing gypsum content is selection by means of near infrared spectroscopy. It is discussed if appropriate test methods exist to evaluate the specific characteristics of recycled concrete aggregates with respect to frost durability. The miscellany of recently published papers, with results based in laboratory studies with accelerated tests led to conclusions relatively optimistic about the use of concrete with recycled concrete aggregates in environments with chlorides.

Enric Vázquez

Chapter 5. Use of Fine Fraction

Abstract

As an outcome of recycling the mineral part of construction and demolition waste significant quantities of the fine fraction, particle size below 4 mm in Europe, are generated. A common feature of the produced fine recycled aggregates is the high content of cement paste that could impair its quality. With the recent advances on the processing technologies improvement on the characteristics of the fine fraction of C&DW can be envisaged and new perspectives to their application arise.

After a brief review of the new technologies developed for C&DW processing, of the characteristics of fine recycled aggregates and of the requirements they must fulfill, an overview of different solutions for the use of the fine fraction is provided. The use in the field of precast concrete elements, of rendering and bedding mortars or for producing cement blends constitute some of the highlighted applications.

Isabel Martins, Annette Müller, Angel di Maio, John Forth, Jörg Kropp, Sergio Angulo, Vanderley John

Chapter 6. Quality Assurance of Recycled Aggregates

Abstract

Recycled aggregates differ from the natural ones in several properties, making their quality lower in general, but suitable enough to be used in different applications inside the construction field in many cases.

On the other hand, recycled aggregates are quite more heterogeneous compared to natural ones, varying their characteristics along the production process. Therefore, quality assurance is extremely important in order to provide users enough confidence in the material, having properties satisfying requirements, and also with defined tolerances on variation throughout a delivery.

Main factors affecting the quality of recycled aggregates are described in this chapter: influence of the production process, types of treatments, Impurities content, quality of the original debris. The composition and the nature of its components as well as the presence of impurities are the principal parameters affecting the final quality of the recycled aggregates. However, some specific methods and operations may be taken into account during the production process in order to obtain suitable recycled aggregate for use in higher-value applications. The control of the incoming deliveries to the recycling plant is also a basic measure to avoid an excessive heterogeneity in recycled aggregates.

In several countries, the standards have been amended in order to cover specific aspects of recycled aggregates, and even some certification systems have been also developed. Different international standards on quality assurance of recycled aggregates are reviewed in this chapter.

Pilar Alaejos, Marta Sánchez de Juan, Jorge Rueda, Roberto Drummond, Ignacio Valero

Backmatter

Titel: Progress of Recycling in the Built Environment
herausgegeben von: Enric Vázquez
Verlag: Springer Netherlands
Electronic ISBN: 978-94-007-4908-5
Print ISBN: 978-94-007-4907-8
DOI: https://doi.org/10.1007/978-94-007-4908-5