Understanding the effect of triethanolamine on grinding and hydration of blast furnace slag, focusing on the degrees of slag consumption and C(-A)-S-H formation

This study investigated the effect of the use of triethanolamine (TEA) on grinding blast furnace slag (BFS) for enhancing hydration performance of slag cement . Raw BFS was pulverized with different dosages (0.02, 0.1, and 0.5 wt%) of TEA then various experiments including the quantification of degrees of slag consumption and C(-A)-S-H formation were conducted. As a result, with increasing TEA content, the aluminate reaction was accelerated while the silicate reaction was retarded. At 0.02 wt% TEA, the change in the fineness and hydration products was barely observed. Meanwhile, at 0.1 wt% TEA, a remarkable enhancement in compressive strength was measured (around 40 % increase). The improvement was explained by (1) a refinement of the slag fineness, (2) an increase in the slag reaction, and (3) porosity reduction. However, although 0.5 wt% TEA still promotes the formation of AFm phases, the hydration of the slag was not enhanced as much as that of TEA 0.1 wt% because of significantly delayed silicate reaction. • The influence of TEA with different dosages was investigated when TEA was used as a grinding agent for BFS. • At 0.1 % dosage of TEA, the most pronounced grinding efficiency was observed, while 0.02 % and 0.5 % of dosages hardly exhibited an improvement in the fineness. • As TEA content increased, the silicate reaction of HVSC was retarded while the aluminate reaction accelerated, resulting in more formation of AFm phases. • The highest 28-day compressive strength was achieved at 0.1 % dosage of TEA due to the enhanced reaction of slag.