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Donplast HC-ST
Cement hydration controlling admixture (Formerly known as Flocrete HC-ST)
  • Reduce concrete waste in case of changing concrete casting schedule.
  • Excellent retardation for long time up to 3 days.
  • Excellent slump retention for very long concrete deliveries.
  • Saving transit mixers drums in case of accident.
  • Reduce the needed amount of water to clean the transit mixer.
  • Chloride-free.

Donplast HC-ST is a liquid admixture formulated from selected polymers specially designed to retard the setting time by controlling the hydration process of Portland cement and other cementitious materials for long time.

This effect can be used to keep concrete mixes workable for a long time starting from 3 hours until 3 days.

  • For wet type shotcrete.
  • For long distance concrete delivery.
  • High-performance concrete.
  • Concrete wash water stabilization.
  • To avoid setting of concrete in transit mixers in case of an accident.

Donplast HC-ST is available in 5 gal (19 litre) containers as well as 275 gal (1,041 litre) and 330 gal (1,249 litre) IBC totes. Bulk supply in tanker trucks is also available upon request.


The recommended dosage of Donplast HC-ST is between 0.75 to 38 fl oz/100 lb (50 to 2,470 ml/100 kg) of cementitious materials in the mix, including GGBFS, PFA or micro-silica.

Actual dosage depends on the desired retardation.

Representative trials should first be conducted to determine the optimum dosage of Flocrete HC-ST to meet the performance requirements by using the materials and conditions in actual use.
For tradi􀆟 onal compliance with ASTM C494, the
recommended dosage is between 0.75 to 5 fl oz/100 lb
(50 - 325 ml/ 100 kg) of cemen􀆟 􀆟 ous materials in the mix.


Donplast HC-ST complies with the requirements of Specification for Chemical Admixture for Concrete ASTM C494 as a Type B admixture.

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Donplast HC-ST
Donplast HC-ST