Mechanisms of silica nano particles effect on mechanical properties of concrete microstructure study

Application of Nano particles is recently shown a powerful potential to improve concrete specification. Few study has previously claimed that introducing little amount of nano particles could improve compressive strength and mechanical properties of concrete. However، these studies reported different and confusing mechanisms for nano effect and reaction that make difficult to developing and predicting other specification of nano concrete، especially durability specification. This paper aimed to study and identify the quality and interaction of these mechanisms، respect to mechanical properties. Laboratory tests and SEM survey is utilized in order to examination of microstructure of nano concrete. The findings of this study explain how and in whether nano particle effect on properties of concrete. It concluded that in the early age Nucleation effect of nano particle can explain the behavior of nano concretes; while by hydration developing، filing effect and pozolanic reaction have higher influence. Findings of this study are extremely agreed with mechanical properties of previous reports