Pre-weighed, chloride based accelerating powder


Specco Set Fast A-98 is a powdered, calcium chloride set accelerating admixture for masonry. Set Fast A-98 is designed to reduce the setting time of the mix, and to help develop early compressive and tensile strengths. Set Fast A-98 speeds the reaction between the cement and water, provides added heat generation, as well as lowers the freezing point of the mix. Set Fast A-98 is conveniently packaged in pre-measured 1 lb. bags with printed instructions for easy addition to the mixer.


  • Provides faster set times in cold temperatures.
  • Increases early strength development.
  • Protects against frost damage.
  • Pre-measures bags allow even job consistency.

COMPOSITION: Calcium chloride powder.

DOSAGE: The recommended Set Fast A-98 dosage is dependent on both working temperature and mortar composition type. For temperatures ranging from 15-32° F, Set Fast A-98 is typically dosed at 2 bags per 94 lbs. of portland cement for portland cement-lime mortars. If masonry cement mortar, or pre-packaged mortar mix bags are used, add 1 bag of Set Fast A-98 for every 2 bags of masonry cement or pre-packaged mortar used. For temperature above 32° F, the above dosages can be reduced as needed. The amount of acceleration obtained will vary with jobsite temperature, air movement, sand and water temperatures, mix design components or other admixtures, as well as heat, insulation, or wind-break protective measures used. For additional reference, Specco recommends following the cold weather masonry construction guidelines listed under Chapter 5 of ACI 531R-79 Building Code Requirements for Concrete Masonry Structures.

AVAILABLE IN: 1.0 lb. bag (25 bags / carton)