Effect of calcium hydroxide on fresh state behavior of sodium carbonate activated blast furnace slag pastes

Aktürk B. , Kızılkanat A. B. , Kabay N.

CONSTRUCTION AND BUILDING MATERIALS, vol.212, pp.388-399, 2019 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 212
  • Publication Date: 2019
  • Doi Number: 10.1016/j.conbuildmat.2019.03.328
  • Page Numbers: pp.388-399
  • Keywords: Alkali activated materials, Sodium carbonate, Slag, Calcium hydroxide, Fresh properties, Carbonate concentration, MECHANICAL-PROPERTIES, PORE SOLUTION, ALKALINE ACTIVATION, REACTION-KINETICS, WASTE GLASS, CEMENT, RHEOLOGY, HYDRATION, STRENGTH, CONCRETE


This study represents the fresh state behavior of Na2CO3-activated ground granulated blast furnace slag (GGBS) pastes. Sodium carbonate (NC) is a suitable activator, though with an extended setting time. To accelerate the hydration process, NC was replaced with sodium hydroxide (NH), then, slaked lime (CH) was used as a carbonate binding agent. This replacement improved the rheological properties, but increased the setting time. The use of 3% CH with GGBS caused a significant decrease in setting time, enabled to set within 6.5 h. The decrement was attributed to the removal of a large amount of dissolved carbonate ions from the fresh state pastes. The NH replacement did not effectively enhance the fresh properties. In the pore solution, the CO32- ion concentration is one of the major parameter that affects the reaction besides other ions released from raw material. (C) 2019 Elsevier Ltd. All rights reserved.