Assessment of salt stress resistance of concrete containing sodium silicate-based nano-silica

Abstract

This study proposes advanced sodium silicate-based nano-silica (SS) as a supplementary cementitious material for enhancing the physical properties and electrochemical performance of the concrete to increase the salt stress resistance of reinforced concrete structures located in the seashore. Moreover, the mixture of the proposed material was compared with ordinary Portland cement and binary-blended cement mixtures, which are conventionally used. In order to evaluate salt stress resistance of reinforced concrete, two different laboratory-scale salt stress environments are artificially designed and one natural place along the seafront is adopted, and reinforced concrete specimens are exposed to those environments. In addition to salt stress resistance properties of all mixtures the compressive strength of all concrete mixtures is conducted. The results of salt stress resistance test for all environments show that the mixtures containing SS have much better salt stress resistance than conventional mixtures. Meanwhile, the amount of SS between 5% and 10% of SS to cement ratio by weight do not significantly affect the salt stress resistance. For compressive strength, specimens containing SS show higher compressive strength than other concrete mixtures.

Keywords

• sodium silicate-based nano-silica
• resistance to salt stress
• chloride ions
• electrochemical reaction