Recycled concretes for aggressive environments: mix design requirements

Author(s): P. Alaejos, M. Sánchez de Juan, C. Thomas, J.A. Polanco, F. Agrela
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 1441- 1451
Total Pages: 10
Language: English

Abstract: 
One of the most unknown aspects of recycled concretes is related to their durability in aggressive environments. In this research, recycled concretes with total coarse aggregate replacement and reference concretes with four increasing w/c ratios (0,45-0,50-0,55-0,65) have been cast to compare the behaviour under accelerated carbonation and water permeability.

Relationships have been established between water penetration depth, carbonation depth and water/cement ratio. Results show that, for the same w/c ratio, the behaviour of recycled concretes is worse due to the porosity of the recycled aggregates. The results are slightly better for carbonation because of the presence of additional cement paste in the particles of recycled aggregates.

On the other hand, differences between reference and recycled concretes decrease for low w/c ratios, as in this case the main factor influencing is the low porosity obtained in the improved new cement paste of the concrete.

According to the results obtained, recommendable water/cement ratios of mixtures for recycled aggregates in aggressive environments will be proposed.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00