Effect of Nano-Alumina on Pore Structure and Durability of Class F Fly Ash Self-Compacting Mortar

Abstract

In this study the effect of pore structure on the mechanical properties and durability characteristics of Self-Compacting Mortars (SCM) containing nano-Al₂O₃ (NA) and class F fly ash are investigated. Al₂O₃ nanoparticles with the maximum size of 15 nm in three different proportions of 1, 3 and 5% of the binder content were utilized to partially replace the cement. The 25% of the cement weight was also replaced by class F fly ash. The pore structure of cement mortars was determined through the Mercury Intrusion Porosimetry (MIP) and Gas Adsorption (BET) methods. The microstructure of the SCMs was evaluated by Scanning Electron Microscopy (SEM). The results indicated a reasonable correlation which was observed between the pore structure and other properties of mortars. The addition of the NA at proportions over 1% led to an increase in the pore volume of specimens by virtue of agglomeration. In overall, it seems that 1% NA can be considered as a suitable replacement regarding the pore structure and hardened properties.