Nano-Silica Modified Recycled Aggregate Concrete: Mechanical Properties and Microstructure

Author: Khaleel H. Younis^1
1Erbil Polytechnic University (EPU), Erbil, Iraq

Abstract:  Sustainability of concrete could be enhanced by incorporating recycled aggregate in the production of concrete. The aim of this study is to assess the effect of using nano-silica (nanoparticles of SiO₂) to improve the performance of recycled aggregate concrete (RAC) containing recycled aggregate (RA) derived from processing construction and demolition waste of concrete buildings. In this study, compressive strength of concrete and the microstructure of RA and RAC with and without nanoparticles of SiO₂ were examined. Nine mixes: one control mix with natural aggregate without nanoparticles, two mixes with RA at 50% and 100% contents (without nano-silica) and three mixes for each content of RA with nano-silica content of 0.4, 0.8 and 1.2% (by mass of cement) were investigated. The results showed that nanoparticles of silica can improve the compressive strength and modify the microstructure of RAC.

Keywords: Nanoparticles SiO₂, Compressive Strength, Recycled Aggregate, SEM

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doi: 10.23918/eajse.v3i3p167

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