Civil Engineering Reference
In-Depth Information
However, due to lack of specifications that ensures the maintenance of safety
and in-use requirement of built elements, the use of this waste material is still in
ordinary applications such as bases and sub-bases of road pavements despite the
potential shown by CDW aggregates in various experimental researches performed
worldwide. This chapter surveys the greatest possible number of standards and
specifications relating to the use of RA in place of natural (primary) aggregates.
For some of these, a direct analysis was possible but others were analysed indi-
rectly through scientific papers, dissertations or topics (Gonçalves
2007
).
This chapter presents an overall review of how the production of concrete with
CDW aggregates is treated in normative standards of different countries, as well as
its response to the need for a sustainable development. Based on existing norms
and specifications that allow the use of RA in the production of concrete, a
comparison is made of the parameters involved, such as density, water absorption
and contaminants ratio within the RA and maximum strength allowed for RA
concrete (RAC).
7.2 Normative Documents
Specifications in use in several countries for the requirements of RA and their
quality control, together with their application and conditions of use are given
below. The comparison of all the parameters is also made in the following section
of this chapter.
7.2.1 Brazil
7.2.1.1 Introduction
In Brazil, specification NBR 15.116 ''Recycled aggregates from construction and
demolition waste'' (2005) allows the use of RA only in non-structural concrete,
and both coarse and fine fractions are permitted in concrete production.
7.2.1.2 Classification
CDW is separated into four classes (A, B, C and D) and of these, waste of Class A
can be considered as aggregate for use in concrete. The waste types that belong to
Class A are the following:
• Construction waste generated in the demolition, renovation and repair of
pavements and other infrastructural works including soil from earthworks;
