Fosroc Construction Grout - Technical Details, Specifications, and Features

Product Overview

Fosroc Construction Grout is a Class A, economical, shrinkage-compensated cementitious grout supplied as a ready-to-use dry powder. It is designed for general-purpose grouting applications in gaps ranging from 10mm to 100mm and is particularly suitable for grouting between base plates and substrates, such as stanchion base plate installations.

Key Advantages

Fosroc Construction Grout offers several distinct advantages for construction applications:

• Gaseous expansion system that compensates for shrinkage and settlement in the plastic state
• Non-shrink performance according to ASTM C1107:2020
• High ultimate strength and low permeability ensuring durability of the hardened grout
• Versatile application methods - can be dry packed, trowelled, poured, and pumped
• No metallic iron content to prevent staining
• Prepackaged material that overcomes potential on-site batching variations
• RCS (Respirable Crystalline Silica) Hazard Free - classified not hazardous for RCS in accordance with Australian Inventory of Industrial Chemicals, containing less than 0.1% RCS

Product Composition

Fosroc Construction Grout is a blend of:

• Portland cement
• Graded fillers (designed to assist uniform mixing and produce consistent grout)
• Chemical additives that provide controlled expansion in the plastic state while minimizing water demand

The low water demand ensures high early strength development.

Technical Specifications and Properties

Standards Compliance

• AS 1478.2-2005: Appendix E Test for Early Volume Change
• AS 1478.2-2005: Table 4.1.2.2 Tests for Consistency

Compressive Strength

The following compressive strength values are measured according to AS 1478.2:2005:

Consistency	Water Addition (L/20kg)	1 Day (MPa)	7 Days (MPa)	28 Days (MPa)
Stiff	2.6	40	55	65
Plastic	3.4	35	50	57
Flowable	3.6	25	45	53

Additional Mechanical Properties

• Flexural Strength (Modulus of Rupture) at flowable consistency (3.6L water): 4.2 MPa (1 day), 8.0 MPa (7 days), 8.5 MPa (28 days)
• Indirect Tensile Strength at flowable consistency: 2.9 MPa (1 day), 4.7 MPa (7 days), 6.0 MPa (28 days)
• Setting Time: 4 hours initial set, 5 hours final set (ASTM C191:2021)
• Fresh Wet Density: 2200 kg/m³ (flowable consistency) per ASTM C185:2020
• VOC Content: 0.65g/litre (ASTM D3960-5)
• Alkali Reactive Particles: Non-reactive (Rapid Mortar Bar Test)

Supply and Packaging

Product Code: FC501000-20KG

Fosroc Construction Grout is supplied in 20kg moisture-resistant plastic bags.

Grout Yield

Allowance should be made for wastage when estimating quantities required. The approximate yields are:

Consistency	Litres of Mixed Material
Stiff	10.4
Plastic	10.7
Flowable	10.8

Mixing Instructions

A forced-action mixer is essential for optimal results:

1. Mixer specification: 140mm helical mixing paddle fitted to a heavy-duty 1600W mixer
2. Mixing speed: Slow speed (400-500 rpm)
3. Mixing duration: 3 to 5 minutes in a suitably sized drum

Water Addition Rates

The selected water content must be accurately measured into the mixing bucket:

Required Consistency	Litres of Water per 20kg Bag	Yield (Litres)
Stiff	2.6 - 3.4	10.4
Plastic	3.4 - 3.6	10.7
Flowable	3.6 - 3.9	10.8

Critical procedure: Always add the powder to the water while mixing continuously for 5 minutes, ensuring a smooth, even consistency is obtained.

Larger Volume Mixing

For larger quantities, a high shear vane mixer is required. Colloidal impeller mixers must not be used.

Application Instructions

Placement Requirements

• Placement time: At 23°C, place the grout within 20 minutes of mixing to gain full benefit of the expansion process
• Maximum thickness: Construction Grout can be placed in thicknesses up to 100mm in a single pour when used as an underplate grout
• Thicker sections: For sections exceeding 100mm, Construction Grout should be filled out with dry, well-graded, silt-free 5 to 6mm aggregate such as Conbextra Grout Aggregate to minimize heat buildup

Bolts and Pockets

Any bolt pockets must be grouted prior to grouting between the substrate and base plate.

Continuous Flow

• Sufficient grout must be prepared before starting
• The time taken to pour a batch must be regulated to the time required to prepare the next one
• Pouring should be from one side of the void to eliminate air or pre-soaking water entrapment under the baseplate
• Grout should be poured across the shortest distance of travel to minimize air entrapment
• Maintain grout head at all times to achieve continuous grout front

Pumping

Where large volumes must be placed, Construction Grout may be pumped using:

• Heavy-duty diaphragm pump (recommended)
• Screw feed or piston pumps (may be suitable)
• Maximum aggregate size for pumping: 0.3mm

Curing

On completion of the grouting operation, exposed areas should be thoroughly cured using:

• Concure curing membrane
• Continuous application of water and/or wet hessian

Temperature Considerations

Low Temperature Working

• When air or contact surface temperatures are 10°C or below on a falling thermometer, use warm water (30-40°C) to accelerate strength development
• For ambient temperatures below 10°C, keep formwork in place for at least 36 hours

High Temperature Working

• At ambient temperatures above 35°C, use cool water (below 23°C) for mixing the grout prior to placement

Storage

• Shelf life: 36 months from date of manufacture if kept in original, unopened bags
• Storage condition: Refer to the manufacture date indicated on the packaging
• Condition requirements: Do not use if there are lumps in the product or if a loss of workability (requiring more water to be added) is experienced

Cleaning

Construction Grout should be removed from tools and equipment with clean water immediately after use. Cured material can be removed mechanically.

Safety Information

A Safety Data Sheet (SDS) and Technical Data Sheet (TDS) are available from the Fosroc website. Both documents must be read carefully prior to use, as application or performance data may change over time. In emergencies, contact any Poisons Information Centre (phone 13 11 26 within Australia) or a doctor for advice.

References

• [1] Fosroc_Construction_Grout_TDS.pdf
• [5] Fosroc_Conbextra_Grout_Aggregate_TDS.pdf