Particle characteristics and hydration activity of ground granulated blast furnace slag powder containing industrial crude glycerol-based grinding aids

• C-GLY can effectively optimize the particle characteristics of ground GBFS powder.
• Hydration degree and activity index of ground GBFS are also improved by C-GLY.
• The properties of C-GLY are close to that of TEA and better than that of glycerol.
• C-GLY as GBFS grinding aids is very feasible.

This paper investigates the viability of industrial crude glycerol (C-GLY) as grinding aids of the granulated blast furnace slag (GBFS). The effects of C-GLY on the particle characteristics and hydration activity of GBFS are studied. The results show that C-GLY can effectively optimize the particle characteristics of ground GBFS. Both the sieve residue and angle of repose of GBFS powder with 0.08 wt% C-GLY are obviously reduced and the specific surface area is improved. The particle size distribution of GBFS powder with C-GLY becomes narrow and particle content of less than 32 μm is obviously increased. In the initial grinding period, the uniformity coefficient of GBFS powder is reduced by C-GLY, while the uniformity coefficient is increased in the latter grinding period. Additionally, 7d and 28d hydration degree of ground GBFS (50 min grinding time) paste with C-GLY are improved by 4.9% and 5.8%, respectively. For the different grinding time, all the activity indexes of different ground GBFS powder are effectively improved by C-GLY. And the uniformity and compactness of hydration products of blended cement paste containing ground GBFS with C-GLY are also improved. By contrast, the action effects of C-GLY on the grinding performance and hydration activity of GBFS are close to that of TEA and better than that of glycerol. Due to the huge cost advantage of C-GLY, its comprehensive performance is better than that of other grinding aids, selecting C-GLY as GBFS grinding aids is feasible.