Omid Nejadkazem - Department of Construction & Mineral Material, Standard Research Institute, Karaj, Iran
Behzad Mehdikhani - Department of Construction & Mineral Material, Standard Research Institute, Karaj, Iran

The alkali activation of industrial sub products (especially those coming from industrial and mining activities) has become an important area of research in many laboratories. It is due to their advantages of low energy cost, high strength and good durability compared to Portland cements. On the other hand concrete can be damaged by a chemical reaction between the active silica constituents of the aggregate and the alkalis in the cement. In the present paper an overview of the advantages and disadvantages of alkali activated cements is presented. Also limitation of alkali content not more than 0.6 percent have been suggested to be benefitted of advantages and prevent disadvantages of alkali aggregate of concrete.

Alkali, Cement, Sub product and Aggregate