Mechanical and microstructural characterization of recycled aggregate concrete containing silica nanoparticles

Abstract

The present study correlates the mechanical properties with parameters of the interfacial transition zone (ITZ) of concrete made with recycled aggregates and nano-silica. Compressive and tensile strength of normal concrete and 100% recycled aggregate concrete incorporating 0 and 3% nano-silica is determined. The ITZ parameters such as porosity and unhydrated cement content along with various minerals present are examined by conducting Backscatter Scanning Electron Microscopic and Energy Dispersive X-ray Spectrometer analysis on thin sections prepared from different types of concrete mixes. In addition, Vickers Microhardness of concrete specimens is determined and relationships are devolved among various mechanical and ITZ parameters. The results of investigation depict that mechanical properties of concrete have strong correlation with ITZ parameters.

Keywords:

• backscatter scanning electron microscopic image
• colloidal nano-silica
• strength
• recycled aggregate concrete
• Vickers microhardness