RLA Penapatch HB80 Mortar

For structural repairs on concrete panels, spalled masonry, and corroded rebar, Penapatch HB80 Mortar is a shrinkage-compensated, polymer-modified structural mortar. It is formulated to achieve high-build vertical and overhead repairs without slumping, restoring structural integrity to damaged substrates while providing low permeability to protect steel reinforcement from chloride attack and carbonation.

How it works

Penapatch HB80 Mortar uses a blend of cements and polymers to form a dense, high-compressive-strength mortar that bonds tenaciously to concrete and masonry. The shrinkage-compensated formulation ensures dimensional stability over the long term, preventing the shrinkage cracking common in standard sand-and-cement mortar repairs. Its high build capability allows installers to rebuild vertical surfaces up to 80mm in a single pass without using formwork, or up to 160mm in small pockets or when supported by temporary forms.

Numbers that matter

• 68 MPa compressive strength (at 28 days, AS1478.2-2005): High structural capacity to support loads on structural concrete panels and columns.
• 10 MPa flexural strength (at 28 days, AS1012-11-2000): Resists bending stresses under load without cracking at the repair boundaries.
• 5mm to 100mm vertical build (up to 180mm horizontal): Allows thick single-application repairs, reducing the need for multi-layer build-ups.
• 1.5 hours initial / 2.5 hours final set time (at 20°C): Provides an efficient work window before setting, minimizing downtime before subsequent finishes can be considered.
• 3.6 litres of water per 20kg bag: Precise water-to-powder ratio required to prevent sag, preserve compressive strength, and control drying shrinkage.

Where to use it

This repair mortar is suitable for internal or external applications on concrete, masonry, steel, and rebar. Common structural repairs include:

• Rebuilding spalled or deteriorated concrete caused by rusted, expanding steel reinforcement.
• Repairing chipped, cracked, or damaged structural concrete panels.
• Overhead, vertical, and horizontal patching where high abrasion resistance is required.

System components

For a complete structural repair, Penapatch HB80 Mortar must be used with the following system components as specified by the substrate and service conditions:

• RLA Zinc Rich Primer: Applied directly to grit-blasted steel and rebar to stop further oxidation and rust.
• RLA Rendergrip A Bonding Agent and Primer: Standard host concrete primer. Apply the mortar while Rendergrip A is tacky. If the primer dries, it must be reapplied. Do not apply over wet primer to avoid slumping.
• RLA Epilox Binder: Required as the substrate primer for damp repairs, areas exposed to occasional or permanent water, or under fully immersed conditions. Apply the mortar while the binder is tacky, not dry.
• RLA Curecon A: Curing compound applied after the final trowel to ensure correct cement hydration, especially in high-wind or exposed conditions.

Limitations

• Concrete substrates must be at least 21 days old before application.
• Do not apply in areas less than 5mm thick, except in very localised spots.
• Do not use when ambient temperatures are below 5°C or above 35°C.
• Ensure the repaired area does not contact water or rain for at least 24 hours after application.
• If the host substrate moves or cracks, reflective cracking will appear in the cured mortar.
• Do not mix part bags, mix by hand, or add more than 3.6 litres of water per bag, as excess water reduces final strength and increases drying shrinkage.