Improvement of the mechanical properties of the cement mortar by the incorporation of silica particles with low and high surface area

Abstract

In recent years, nanoaprticules with different sizes have been incorporated in the cement mortar in order to improve their mechanical characteristics. The present work focuses onto the influence of the silica nanoparticles (SiO2) with low and high surface area over the stability and mechanical properties of the cement mortar. The quantities of nanosilica added into the cement mortar to ameliorate their mechanical characteristics vary from 0.5 % to 1.5 %wt. The obtained material after the incorporation of the SiO2 nanoparticles have been characterized by several techniques such as TG, DTG, DSC and their morphologies were determined by using SEM analysis. The workability, water absorption, compressive and flexural strengths of these materials have also been evaluated. The results obtained show that the introduction of the SiO2 nanoparticles into the cement mortar has been greatly improved their compressive and flexural strengths, and the specimens incorporated by nanosilica with high surface area are found more effective than those containing the silica nanoparticles with low surface area, suggesting that the specific surface play a crucial role in the improvement of their mechanical properties. The results show also that the appropriate dosage of silica nanoparticles in the cement mortar to have a maximum enhancement of their mechanical properties was found around 1.5 wt% by weight of cement for the nanosilica with high surface area.

Keywords

• Cement mortar
• Compressive and flexural strengths
• Nanosilica
• Workability