Water penetration resistance of the self-compacting concrete by the combined addition of micro and nano-silica

Abstract

This paper presents the combined effects of micro-SiO2 (MSi) and nano-SiO2 (NSi) on the water permeability and absorption of the self-consolidating concrete (SCC). To this aim, eight mixes of the SCC were created with w/b ratio of 0.45 and various proportions of NSi and/or MSi as following; 10% MSi, 1, 2 or 3% NSi, 9% MSi + 1% NSi, 8% MSi + 2% NSi, and 7% MSi + 3% NSi. Consequently, the experimental study showed that the combination of MSi and NSi had a good effect on the water penetration resistance of the SCC. The combination of 9% MSi + 1% NSi lowered the water penetration depth of the SCC nearly 58% and the short-term and total water absorption by approximately 23% and 30%, respectively. The combined addition of MSi and NSi could be more effective; as a result, the microstructure of the SCC would be more uniform and compact, thereby enhancing the water resistance.