Factor affecting hydration rate of cement:
- The phase composition of cement. Different types of cement have varying chemical compositions, which can influence the rate of hydration.
- The amount and form of gypsum in the cement: whether gypsum is present in the dihydrate, hemihydrate. or the anhydrite form.
- Fineness of cement: Higher the fineness, higher the rate of reaction due to availability of a large surface area.
- water cement ratio of mix: At high W/C, hydration may progress till all the cement is consumed, while at low W/C the reaction may stop altogether due to lack of water.
- Curing condition: The relative humidity can have major effects on the process of hydration.
- Hydration temperature: Increase in temperature generally cause an increase in the rate of the reaction, although the hydrated structure can be different at different temperature.
- Admixtures, such as accelerators and retarders, can be added to the mix to control the hydration rate. Accelerators speed up hydration, while retarders slow it down.
- Presence of chemical admixture: For example, plasticizers, and set controllers.
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