Abstract
The effects of limestone powder (LP) on the performance of Portland cement based composites have been extensively studied, considering that LP not only acts as nuclei sites, but that it is also chemically involved in the hydration process, which improves the reaction degree at the early age. In high calcium containing alkali activated system, the function of LP is considered as inert filler, probably due to the low solubility of calcium carbonate. However, the role of LP may differ in sodium carbonate activated slag (AAM) with respect to the initial precipitated calcium carbonate sharing the same chemical composition to LP. By replacing the solid ingredient ground granulated blast furnace slag (GGBS) with LP at different levels (5%-30% by mass of slag), the reaction kinetics and compressive strength of sodium carbonate activated slag-LP blends were studied. The results show that the reaction of sodium carbonate activates is slightly accelerated when the content of LP is within 5%. When further increasing the LP content, the reaction process is gradually delayed. Besides, the intensity of the reaction as shown by calorimetric measurement is increased with up to 10 % of LP. On the other hand, the compressive strength of mixtures benefits from the incorporation of LP till 15%, and then decreases 2.4% when 30% LP is used. Furthermore, the highest strength was achieved with 10% replacement of LP, which is in line with the calorimetric results, indicating that the incorporation of LP accelerates the reaction of sodium carbonate activated slag.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 9th International Concrete Conference, 4-6 July 2016, Dundee, Scotland |
| Place of Publication | s.l. |
| Publisher | s.n. |
| Pages | 348-355 |
| Number of pages | 8 |
| Publication status | Published - 4 Jul 2016 |
Keywords
- Limestone powder
- sodium carbonate
- ground granulated blast furnace slag
- reaction kinetics
- mechanical properties