Triethanolamine and triisopropanolamine on slag cement impact of hydration process
The slag cement has the advantages of low hydration heat, high late strength, inhibition of alkali aggregate reaction, and resistance to sulfate corrosion, and has been applied in a large number of projects. When producing slag cement, because the slag is more greasy than the clinker, the best active particle size can not be achieved when co-grinding, and the single grinding will cause a lot of energy consumption, so it is used in the grinding process. Grinding aids to reduce grinding energy consumption and improve cement performance. Triethanolamine (TEA) and Triisopropanolamine (TIPA) are the main components of common grinding aids. They have strong polarity and can reduce the free energy of cement particles, prevent particle agglomeration and increase particles. The specific surface area can also accelerate the hydration rate of clinker minerals, so it has attracted extensive attention from scholars at home and abroad. Previous studies have focused on the grinding effect of alcohol-amine organic compounds and their composites on cement. The research on the mechanism of TEA and TIPA on hydration of slag cement is still rare. Both TEA and TIPA can reduce the fineness of slag cement, increase the specific surface area, increase the content of fine particles, increase the water demand of cement, but have less effect on the setting time; TEA and TIPA have a significant effect on the strength of slag cement. The strength of slag cement increases with the increase of the amount of grinding aid. The compressive strength of cement with 0.05% TIPA increases by 5.58 MPa. The enhancement effect of TIPA on slag cement is obviously better than that of TEA. Under the action of TEA and TIPA, the hydration rate of slag cement is accelerated, the type of hydration product is unchanged, but the quantity is increased and the crystallinity is better. These hydration products are cross-linked to form a more dense structure.