Mechanical properties of cement mortar with Al 2O3 nanoparticles

Abstract

In this Paper, the split tensile and flexural stren gth together with the setting time of concrete by p artial replacement of cement with nano-phase Al 2O3 particles has been studied. Al 2O3 nanoparticles with the average diameter of 15 nm were used with four different contents of 0.5%, 0.1%, 1. 5% and 2.0% by weight. The results showed that the use of nano- Al 2O3 particles up to maximum replacement level of 2.0% produces concrete with improved split tensile streng th. However, the ultimate strength of concrete was gained at 1.0% of cement replacement. The flexural strength of fresh concrete was increased by increasing the content of Al 2O3 nanoparticles. The setting time of fresh concrete was decreased by increasing the content of Al 2O3 nanoparticles. It is concluded that partial replac ement of cement with nanophase Al 2O3 particles improves the split tensile and flexural strength of concrete but decreases its setting time. (Journal of Americ an Science 2010;6(4):94- 97). (ISSN: 1545-1003).