This paper reports on the development of artificial aggregates based on granulated reactive silica (AAGS) powder materials activated by alkaline components. The alkali content was optimized depending on the properties of the reactive silica (RS) material. The best RS component for AAGS was determined to maximize the volume of synthesized soluble polysilicates. Additional research was conducted to evaluate the materials for the formation of a strong shell for AAGS. The effect of RS and AAGS composition on the structure of hardened cement composite was investigated. (C) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.