RLA UW Penaflow Grout

For structural grouting underneath precast concrete panels, filling core holes, and securing anchor bolts, UW Penaflow Grout is a Class A non-shrink cementitious grout that controls settlement using a gaseous expansion system. It is formulated to eliminate shrinkage while in a plastic state, ensuring complete contact and load transfer between concrete substrates and base plates.

How it works

UW Penaflow Grout uses a pre-blended mix of Portland cement, graded aggregates, and chemical additives that trigger a 1% to 2% volumetric expansion while the mix is still plastic. This expansion begins 15 minutes after mixing and finishes within 3 hours, pushing the grout into close contact with unrestrained surfaces before curing begins. The formula contains no metallic iron, preventing rust staining on exposed concrete panel edges and joint lines.

Numbers that matter

• 20mm to 150mm application thickness: Allows single-pass pours underneath precast sections and inside deep cavities without the risk of thermal cracking.
• 55 MPa compressive strength (at 28 days): Provides high load-bearing capacity for underpinning and structural base infills (tested to AS1012.9 and AS2073).
• 10 MPa bond strength (at 28 days): Ensures high-strength adhesion to structural concrete surfaces, measured via the ASTM C882-1987 Slant Shear Method.
• Adjustable consistency yields: A 20kg bag yields 10.3 litres as a dry pack, 10.6 litres when trowellable, and 11.0 litres when mixed to a flowable consistency.

Where to use it

• Grouting underneath precast concrete panels and structural concrete sections.
• Filling core holes created in panels by core drilling.
• Securing anchor bolts and filling structural cavities, gaps, and base infills.
• Core filling in block work and structural underpinning.

Limitations

• Do not mix by hand: Must be mixed using a mechanical forced-action mixer, high shear mixer, or a drill with a spiral mixing paddle at 500-600 rpm.
• Strict water limits: Do not add water beyond the specified ratios (maximum 2.9L for dry pack, 3.4L for trowellable, and 4.0L per 20kg bag for flowable). Excess water causes segregation, bleeding, and loss of strength.
• Do not vibrate: Mechanical vibration must not be used to assist flow; rely on gravity flow with a header box or a positive displacement pump.
• Temperature limits: Only apply when substrate and ambient temperatures are between 10°C and 30°C. Cold temperatures extend setting and strength development times; high temperatures accelerate setting and may cause cracking.
• Substrate condition: Never apply mixed grout to a dry porous substance; the concrete must be pre-soaked with water for 4 hours before application.

How to apply

Saturate the concrete substrate with clean water for 4 hours before grouting to reduce porosity and prevent water loss from the mix. Remove all excess water, puddles, and standing water from bolt holes and cavities prior to pouring.

Formwork must be constructed to be completely watertight. Seal the base of the formwork using foam rubber strips or a polyurethane or silicone sealant. Build the formwork to maintain a grout head on the pouring side, allowing continuous gravity flow beneath the base plate to prevent air entrapment.

Always add the grout powder to pre-measured cold water. Mix mechanically for 3 to 5 minutes until a homogeneous consistency is reached. Discard any mix that has begun to stiffen or has become unworkable.

Once placed, protect all exposed grout surfaces immediately by covering them with plastic sheeting, wet hessian, or a liquid curing compound such as the Curecon range.