Carbonation resistance of self-compacting recycled aggregate concretes with silica fume

Abstract

The paper presents the results of carbonation resistance of Self-Compacting Concrete (SCC) made with coarse recycled concrete aggregates and fine recycled concrete aggregates. To evaluate the carbonation resistance of SCC mixes, two different groups consisting of nine SCC mixes were prepared. The impact of coarse recycled concrete aggregates and fine recycled concrete aggregates has been quantified based on the observed performance of SCC mixes of Group-I whereas, the influence of Silica Fume (SF) has been observed on the SCC mixes of Group-II. The incorporation of SF in various SCC mixes not only improves the compressive strength, the carbonation resistance is significantly increased. It has also been observed with the scanning electron microscopy analysis that the incorporation of SF in SCC mixes containing different contents of recycled concrete aggregates, resulted in the production of SCC mixes, with higher/comparable performance to that of control SCC mix.

Keywords:

• carbonation
• self-compacting concrete
• recycled concrete aggregates
• silica fume
• scanning electron microscopy

Acknowledgements

The authors acknowledge the support of the staff of Structures Testing Laboratory at Dr. B R Ambedkar National Institute of Technology, Jalandhar, India during the experimentation work reported in the paper.