The effect of temperature rise inhibitor on the hydration and strength development of slag/fly ash blended cement paste

This study compares the effects of Temperature Rise Inhibitor (TRI) on the exothermic process and development of compressive strength of slag/fly ash blended cement systems. Isothermal calorimetry results reveal that, even if there is an enhancement effect on cement hydration due to the filler effect, TRI can still effectively lower the hydration heat flow of composite cementitious materials during the early age. By adjusting the content of TRI and SCMs, these two opposite effects will reach a balance at a critical dosage. However, a distinct effect of TRI on compressive strength development can be observed in these two systems. In the slag system, the compressive strength of the TRI-blended sample can catch up with the reference within 28 days. While in the fly ash system, it takes longer to recover to the normal level. In addition to the difference in SCMs' intrinsic hydration reactivity in alkaline cement paste, competitive adsorption of TRI between cement and SCMs particle and the change of pore structure further enhance the variation in later strength development.