Hydroxypropyl methylcellulose has many effects on cement hydration
August 24, 2020
Hydroxypropyl methyl cellulose has a delay in the hydration of cement-based mortar, and the delay effect increases with the increase of the cellulose content. The influencing factors of cellulose on cement hydration are: dosage, degree of etherification and cement type.
The influence of cellulose content on cement hydration: The influence of hydroxypropyl methylcellulose content on cement hydration is that the test temperature of cement slurry is 23°C, and the heat flow meter is used to measure the heat of hydration reaction. Isothermal calorimetry is to analyze the influence of cellulose on the hydration time of inorganic mineral binder by tracking the change of heat. The addition of cellulose delays the hydration of cement. The higher the amount, the greater the impact.
The degree of cellulose etherification affects cement hydration: In mortar products, the degree of etherification of hydroxypropyl methylcellulose affects the setting time of cement. The higher the degree of etherification of cellulose, the greater the impact on cement hydration.
The effect of cement type on cement hydration under the same cellulose: the effect of cement type on hydration, the test is based on cement-based tile binder, which contains 40% cement and 0.5% MC, and the amount of water added is 25%. Cement hydration starts earlier, and its strength increases faster; blast furnace cement hydrates more slowly than composite cement.