421 CI Rapid 65LB Bag: 2 Hour Fast Set


  • Full depth repairs
  • On grade, above, and below grade on concrete
  • On horizontal surfaces
  • Vertical and overhead surfaces when formed and pumped or poured
  • As a structural repair material for parking facilities, industrial plants, walkways, bridges, tunnels, dams and balconies
  • Filler for voids and cavities
  • High early strength
  • Fast-setting
  • Integral corrosion inhibitor
  • Prepackaged coarse aggregate: Eliminates need to extend material in the field; Eliminates the risk of reactive aggregate
  • Excellent workability and finishing characteristics
  • Rapid hardening as defined by ASTM C-928 (Type R3)
  • VDOT Approved

Product Data Sheet

Safety Data Sheet

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SKU: SIKACRETE421RAPID Category: Tags: , , , , , ,

421 CI Rapid 65LB Bag: 2 Hour Fast Set

421 CI Rapid is a one-component, early strength-gaining concrete containing factory blended coarse aggregate. Sikacrete 421 CI Rapid is a one-component, early strength-gaining concrete containing factory blended coarse aggregate. This concrete is air entrained and also contains a migrating corrosion inhibitor. Single Component, just add water. Questions? Contact us


  • Start mixing with 5.5 pints (2.6 L) of water.
  • An additional 0.5 pint (0.2 L) can be added if needed.
  • Do not overwater as excess water will cause segregation.
  • Add Sikacrete®-421 CI Rapid while continuing to mix. Mix to a uniform consistency, maximum 3 minutes. Mechanically mix with a low-speed drill (400–600 rpm) and paddle or in appropriate-size mortar mixer or concrete mixer.


  • Pre-wet surface to SSD.
  • Ensure good intimate contact with the substrate is achieved. To accomplish this, material should be scrubbed into the substrate or other suitable means should be employed such as vibration of the material or pumping under pressure.
  • Vibrate form while pouring or pumping.
  • Pump with a variable pressure pump.
  • Continue pumping until a 3 to 5 psi increase in normal line pressure is evident then STOP pumping.
  • Form should not deflect.
  • Vent to be capped when steady flow is evident, and forms stripped when appropriate.


  • As per ACI recommendations for Portland cement concrete, curing is required.
  • Moist cure with wet burlap and polyethylene, a fine mist of water or a water based* compatible curing compound.
  • Curing compounds adversely affect the adhesion of following lifts of mortar, leveling mortar or protective coatings.
  • Moist curing should commence immediately after finishing. Protect freshly applied mortar from direct sunlight, wind, rain and frost.

* Pretesting of curing compound is recommended.


  • 0.5 ft3 (0.01 m3)per bag
  • (Coverage figures do not include allowance for surface profile and porosity or material waste)

Sika USA

Weight 26.50 lbs
Dimensions 50.8 × 30.48 × 7.62 in