ProSpec® Slab Bedding Grout Rapid

1 of 5 products in this brand
ProSpec® Slab Bedding Grout Rapid is an ultra-fast-setting, non-shrink, high-compressive-strength, load-bearing, non-metallic grout designed for placing precast concrete slabs. It is cement-based and non-corrosive. This highly fluid grout can be pumped through 1 1/4" (32 mm) grout ports and helps in extending the set time.

Product Type: Grout

Features: Cementitious, Fast Setting, Good Compressive Strength, Non Corrosive

Chemical Family: Polyurethanes (PU)

Technical Data Sheet
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Identification & Functionality

Features & Benefits

Labeling Claims
Ready-to-Use Product Features
Product Benefits
  • Highly fluid, can be pumped through 32 mm grout ports
  • Ultra-fast set: up to 2,500 psi compressive strength in 1 hour
  • Non-metallic
  • Cement based, non-corrosive
  • Set time can be extended by using ProSpec® Set Extender

Applications & Uses

  • Ideal for bedding grout for precast concrete roadway panels
  • Fill small voids between the prepared sub-grade and precast concrete slabs
  • Ideal for grouting applications of limited clearance


  • All materials should be stored at 7.2°C to 27°C 24 hours prior to installation.
  • All grout access ports must be free of any obstructions, dirt, grease, oil or other contaminants.

Note: It is the responsibility of the installer/applicator to ensure the suitability of the product for its intended use.

Job Mockups:

The manufacturer requires that when its ProSpec® products are used in any application or as part of any system that includes other manufacturers’ products, the contractor and/or design professional shall test all the system components collectively for compatibility, performance and long-term intended use in accordance with pertinent and accepted industry standards prior to any construction.


  • Ideal mixed product temperature at placement is 18º- 24ºC, where the initial setting time is 7-15 minutes. Higher temperatures will shorten setting time, while lower temperatures will extend setting time.
  • Hot Weather: Keep Slab Bedding Grout Rapid cool and adjust using ProSpec® Set Extender.
  • Cold Weather: Do not use antifreeze. Warm water can be used.

Mixing (at 4.4-24°C):

  • Mix as close to the area being installed as possible.
  • Use 6.0-6.3 qt. (5.7-6.0L) clean potable water per 16 kg. bag.
  • Place the potable water into a mortar mixer or similar mechanical mixer and add the grout while mixing. Due to the ultra-rapid setting feature of Slab Bedding Grout Rapid, do not mix by hand.
  • Mix for about 2 minutes to a lump-free consistency.
  • Do not re-temper or add extra water after mixing is complete.
  • To achieve optimum flow, continuous agitation is required.

Note: The water quantities shown are approximate and may vary slightly with type of equipment and application conditions.
Mixing (at 27-38°C):

The optimum placement air and temperature range is 18 - 24°C. For applications above this range of temperatures, use ProSpec® Set Extender to adjust the set time.

  • Slab Bedding Grout Rapid is installed by pumping into the grout distribution system cast into each slab.
  • The grout is very fluid, but will take a short while to disperse beneath the slab, so that the port will need to be refilled occasionally until the level ceases dropping in the port.
  • Continue with the pumping of grout into each distribution channel until all the channels in each slab are grouted.

Note: The water quantities shown are approximate and may vary slightly with type of equipment and application conditions

Set Extender per 35 lb. Slab Bedding Grout Rapid Initial Set (minutes):

Bags of Set Extender 40ºF 50ºF 60ºF 70ºF 80ºF 90ºF 100ºF
0 61 34 16 12      
1 116 60 30 15 12    
2 144 90 49 27 16 13 12
3 174 104 55 36 22 15 16

Clean tools immediately before Slab Bedding Grout Rapid sets, typically 10 - 25 minutes.

  • Do not re-temper after mixing
  • Do not overwater, add other cements or additives
  • Do not exceed 2 inches in one lift

16 kg bag = 11.3L


Technical Data
ValueUnitsTest Method / Conditions
Strength (at 73°F, 1h)min. 17.2MPa-
Strength (at 45°F, 1h)min. 13.8MPa-
Strength (at 73°F, 1 day)min. 41.4MPa-
Strength (at 45°F, 1 day)min. 37.9MPa-
Strength (at 73°F, 7 day)min. 52.4MPa-
Strength (at 45°F, 7 days)min. 41.4MPa-
Strength (at 73°F, 28 days)min. 55.1MPa-
Strength (at 45°F, 28 days)min. 48.3MPa-
Expansion0 - 3%ASTM C940
Bleeding (for 30 min)max. 0.1%ASTM C940
Efflux Timemax. 20sASTM C939
Grout Bond Strength (Bond to dry PCC - CT551, at 24 hr)427.0psi-

Packaging & Availability

Packaging Type
Regional Availability
  • North America
Packaging Information

15.87 kg bag

Storage & Handling

Shelf Life
6 Months
Storage Condition

Store in the original, unopened container, away from moisture, under cool, dry conditions and out of direct sunlight.