Effects of the combined usage of micro and nano-silica on the drying shrinkage and compressive strength of the self-compacting concrete

Abstract

In this paper, the effects of the combined usage of micro-silica (MSi) and/or nano-silica (NSi) on the drying shrinkage and compressive strength of the self-compacting concrete (SCC) were investigated. For this purpose, twenty-four types of the SCC mixes made with w/b ratios of 0.35, 0.40, and 0.45 and different percentages of MSi and/or NSi were applied in this research. The replacement ratios included 10% of MSi, 1, 2 or 3% of NSi, 9% MSi + 1% NSi, 8% MSi + 2% NSi, and 7% MSi + 3% NSi. The obtained results revealed that the combined use of 9% MSi + 1% NSi reduced the 150-day drying shrinkage of the SCC up to 17%, while it increased the 90-day compressive strength of it by 38%, as compared to the control sample. Moreover, it was found that replacing cement by MSi and NSi led to certain synergistic effects and their combination was stronger than the sums of the individual uses.

Keywords:

• SCC
• drying shrinkage
• compressive strength
• nano-silica
• micro-silica

Disclosure statement

No potential conflict of interest was reported by the authors.