Diethanol-isopropanolamine (DEIPA) is an alkanol amine used in the formulation of cement additives and concrete admixtures. Besides being a good grinding aid in the cement mill, DEIPA increases the strength of cements at all hydration ages, and cements blended with fly ash and slag tend to show a greater response to the chemical.In this research, the impact of DEIPA on the hydration of blast furnace slag blended cements is studied using several analytical techniques, such as quantitative X-ray diffraction with Rietveld refinement (QXRD), scanning electron microscopy (SEM) with backscattered electron image analysis, thermogravimetric analysis (TGA), and chemical shrinkage. Isothermal calorimetry was also used to demonstrate the impact of DEIPA on the reactivity of slag in blended cements.Compressive strength tests were performed to assess the impact of the amine in such cements.It is demonstrated that DEIPA increases the mortar strength by enhancing primarily the aluminate hydration and the morphology and composition of the hydrates, such as calcium hydroxide and C-S-H.The visual observation was confirmed by isothermal calorimetry, where DEIPA was found to directly enhance the rate of reaction of granulated blast-furnace slag after 48 hours of hydration.