Validation of carbonation behavior of self compacting concrete made with recycled aggregates using microstructural and crystallization investigations

Abstract

The sustainable binary and ternary blends of Self compacting concrete (SCC) were prepared with replacement of natural fine aggregates (NFA) and natural coarse aggregates (NCA) with recycled fine aggregates (RFA) and recycled coarse aggregates (RCA) respectively sourced from construction and demolition (C&D). Accelerated carbonation tests were conducted using conventional acid/base method. The results indicate that with the increase in RFA and RCA content as replacement of NFA and NCA, decrease in the carbonation resistance of SCC has been observed. The addition of Metakaolin (MK) has been found in recompensing the respective loss in carbonation resistance up to some extent. For validating the results, microstructural and crystallization studies have been performed with the help of Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. In addition to above, compressive strength tests were also conducted for reference.

Keywords:

• Carbonation
• natural aggregates
• recycled aggregates
• self compacting concrete
• scanning electron microscopy
• X-ray diffraction

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 article.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The financial assistance in the form of fellowship to the first author from the Ministry of Human Resource Development (MHRD), Government of India is appreciatively acknowledged.