Mechanical Properties and Permeability of Mortar Modified with Metakaolin

This paper deals with the mechanical properties and permeability of mortar modified with Metakaolin. Comparisons were made to normal mortar without metakaolin in order to determine its influence of addition and replacement percentage. Cement was replaced on a mass basis of 5%～20% for metakaolin. The permeability determined by the electric flux and water absorption was investigated as well as mechanical properties. Technique of Scanning electron microscopy (SEM) was employed to characterize the microstructure of the new mortar system. The experimental results obtained reveal that Metakaolin contributed to lower the water absorption rate and the electric flux and yield a good mechanical property. Moreover,there exists an optimal displacement percentage of metakaolin,15%,in the mortar system. SEM pictures illustrate that Metakaolin makes mortar more compacted. Evidence can be given that Metakaolin can be applied to protect the steel reinforcement of concrete from corrosion.