Criteria for the Use of Fine Recycled Concrete Aggregates in Concrete Production

Title: Criteria for the Use of Fine Recycled Concrete Aggregates in Concrete Production
Author(s): Evangelista
Paper category : conference
Book title: International RILEM Conference on the Use of Recycled Materials in Building and Structures
Editor(s): E. Vázquez, Ch. F. Hendriks and G.M.T. Janssen
Print-ISBN: 2-912143-52-7
e-ISBN: 2912143756
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 503 - 510
Total Pages: 8
Nb references: 10
Language: English

Abstract: In many research programs, recycled aggregates from concrete have been used to produce
new concrete with promising results. However, in almost all of these research programs, only
the coarse aggregates have been used and it was taken for granted that the fine portion was
unsuitable for this purpose. Nevertheless, in many countries the extraction of fine natural
aggregates (sand) has had tremendous environmental repercussions, namely in rivers and sea
coastal areas.
The present research program, in which concrete has been produced with different ratios of
substitution (10%, 20%, 30%, 50% and 100%) of natural sand with fine recycled concrete
aggregates, has been divided in three parts: tune-fining the workability of the admixtures in
order to keep it approximately constant; choosing the maximum allowable substitution ratio
according to performance criteria; performing a large set of laboratory tests to compare the
behaviour of concrete with that same substitution ratio of fine recycled aggregates with the
behaviour of a reference concrete produced exclusively with fine natural aggregates. In all
compositions, the coarse portion is made of natural limestone aggregates.
The present paper partially describes the first and second parts of this research program
and the criteria used to limit the maximum replacement ratio, based on compressive strength,
short-term shrinkage and water absorption.

Online publication: 2004-09-29
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143756.056