Concrete retarder delays the initial setting time of concrete, that is, it inhibits the hydration rate of cement. Early strength additives increase the hydration rate and facilitate the early improvement of concrete strength. The two cannot be mixed. The former is used for temperatures above 5 degrees, and the latter is used for temperatures below -5 degrees. If you want to know the difference between them, let us first take a look at their respective scope of application. You already know it from the literal meaning, one is to slow down the curing, and the other is to speed up!
Retarder, retarding water reducing agent and retarding high-efficiency water reducing agent can be used in large-volume concrete, roller compacted concrete, concrete constructed in hot climate conditions, concrete poured in large areas, and to avoid cold joints Concrete produced, concrete that needs to be parked for a long time or transported over long distances, self-leveling vibration-free concrete, concrete constructed with slip form construction or pull form construction, and other concrete that needs to delay the setting time. It is suitable for use in concrete construction where the daily minimum temperature is above 5°C. It is not suitable to be used alone for concrete and steam-cured concrete with early strength requirements. When used, the variety should be selected according to the temperature and the dosage should be adjusted to meet the engineering requirements before use.
Early strength agent and early strength water-reducing agent are suitable for steam-cured concrete and concrete projects with early strength requirements constructed in environments with normal temperature, low temperature and the lowest temperature not lower than -5℃. It is not advisable to use early-strengthening agents and early-strengthening water-reducing agents in hot environments.
From the above two aspects, it can be generally seen that these two admixtures should not be used at the same time.
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