For high-build structural concrete restoration on vertical, horizontal, or overhead faces, Penapatch HB50 Mortar provides a shrinkage-compensated, medium-weight repair barrier. It is formulated to reinstate structural integrity in damaged concrete panels and spalled areas caused by reinforcing steel corrosion, reaching a high ultimate compressive strength of 55 MPa at 28 days without requiring formwork for standard vertical builds up to 80mm.
Penapatch HB50 Mortar forms a low-permeability barrier that resists carbon dioxide and chloride intrusion, protecting embedded steel rebar from carbonation and corrosion. The polymer-modified cementitious design provides high adhesion to concrete and masonry substrates while managing drying shrinkage (under 350 micro-strain at 28 days) to prevent edge curling or separation. It can be applied manually with a trowel or gloved hand, or wet-sprayed and pumped through a nozzle for larger-scale compaction on site.
Prepare the substrate to a minimum depth of 5mm to avoid feather-edging, breaking out up to a clean saw-cut edge. Remove all weak concrete, laitance, and contamination by scabbing or high-pressure water blasting. Clean any corroded steel rebar to a bright condition using grit blasting, and prime immediately with RLA Zinc Rich Primer, ensuring the zinc primer does not contact the host concrete.
Prime concrete and masonry surfaces with RLA Rendergrip A Bonding Agent and Primer, allowing it to reach a tacky consistency before mortar application. If the primer dries, it must be re-applied. For porous substrates, pre-soak with water and remove excess before priming. For repairs exposed to permanent or occasional dampness, or for fully immersed applications, prime the substrate with RLA Epilox Binder.
Mix using a mechanical forced-action mixer with a high-shear spiral paddle. Do not use free-fall mixers, do not mix part bags, and do not hand-mix. Add the 20kg powder to exactly 3.0 litres of clean water and mix for 3 to 5 minutes until homogenous. Compact the mortar thoroughly into the substrate and around exposed rebar, finishing with a steel trowel without overworking the surface. Cure using RLA Curecon A in accordance with good concrete practice. Decorative or protective coatings may be applied directly over the cured surface.
Typical single-lift range is 5–80 mm on vertical surfaces. In small pockets or with formwork, depths up to ~120 mm are achievable. For thicker sections, build in layers with adequate curing between lifts.
Use ~3.0 L of clean water per 20 kg bag. Mix to a cohesive, non-slump consistency suitable for vertical or overhead placement. Do not over-water and do not re-temper.
Covers approximately 1.85 kg/m²/mm. A 20 kg bag yields about 1.08 m² at 10 mm thickness. Always allow for substrate profile and wastage.
Yes. It is suitable for internal and external applications on properly prepared concrete. Protect fresh repairs from rain, sun and wind during early cure.
Once the repair has hardened and dried sufficiently. Timing depends on thickness and conditions. Follow the coating manufacturer’s moisture/strength requirements and carry out a moisture check before coating.
Apply between 5–35 °C. In hot or windy conditions, cool materials where possible and implement curing to prevent rapid moisture loss.
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Spalled concrete repairs around corroded reinforcement | High build with strong bond and low permeability for durability | Remedial contractors, builders |
| Vertical/overhead patching of columns, beams, soffits | Thixotropic, non-slump placement up to 80 mm in a pass | Builders, civil contractors |
| Precast panel edge and corner reinstatement | Shrinkage-compensated, high early/ultimate strength for crisp edges | Precast installers, remedial specialists |
| Durability repairs in chloride-exposed infrastructure | Low permeability to resist chloride ingress and carbonation | Engineers/specifiers, asset maintenance |
Cut back to sound concrete; remove weak/contaminated material. Clean and pre-dampen to SSD. Protect adjacent finishes.
Scabble, grind or high-pressure water-blast to expose sound aggregate and provide a profile.
Saw-cut to a minimum depth to avoid feather edges and ensure patch integrity.
Add powder to ~3.0 L clean water per 20 kg while mixing with a low-speed drill (≈400–600 rpm) or paddle mixer. Mix to a cohesive, thixotropic paste.
Adjust within manufacturer tolerance for placement method; do not over-water.
For difficult substrates, prepare a thin bonding slurry and apply wet-on-wet before main placement.
Press firmly into the substrate, compact to eliminate voids, and build to the required thickness.
Single pass 5–80 mm vertical/overhead; up to ~120 mm in small pockets or with formwork. Layer for deeper sections.
Float/sponge finish once material has firmed sufficiently; avoid over-working the surface.
Protect fresh repairs from rapid drying, rain and temperature extremes. Implement curing suitable to conditions (e.g., curing compound, damp hessian, or shade).
Overcoat once the repair has hardened and dried to the coating manufacturer’s requirements. Verify moisture and surface condition before coating.
Wear gloves, safety glasses and a P2/P3 dust mask when handling powder and mixing. Use protective clothing to avoid skin contact.
Ensure good ventilation during mixing and placement, especially indoors or in confined spaces.
Non-flammable. Avoid generating airborne dust. Store sealed in a cool, dry area away from moisture uptake.
Seek medical attention immediately in all cases of serious exposure.
Mechanically remove laitance, weak or contaminated layers; break out to sound substrate. Saw-cut perimeter; avoid feather edges. Pre-dampen to SSD (surface-saturated, no standing water).
Where substrates are highly absorbent or placement conditions are challenging, a compatible bonding slurry (HB50 mixed to a thin slurry) may be used to promote adhesion. Place wet-on-wet.
Bonding slurry (site-made)Clean to bright metal; remove rust/scale. Replace severely corroded sections per engineering advice.
If specified, apply an appropriate steel primer/passivator and allow to cure before placing HB50.
Steel passivating primer (as specified)Prepare to sound concrete and SSD. Maintain minimum thickness; compact to avoid entrapped air.
Where substrate is very smooth, lightly roughen to create a mechanical key.
—Remove friable material; roughen and clean. Pre-dampen to SSD prior to placement.
Use a cementitious bonding slurry or compatible bonding agent per project spec.
Cementitious bonding slurry| Property | Value |
|---|---|
| Base Chemistry | Polymer-modified, Fibre-reinforced cementitious mortar |
| Colour | Grey |
| Density | 2120 kg/m³ (approx.) |
| Compressive Strength | 1 day: 15 MPa, 7 days: 40 MPa, 28 days: 55 MPa |
| Flexural Strength | 1 day: 5 MPa, 7 days: 7 MPa, 28 days: 8.5 MPa |
| Shrinkage | Shrinkage compensated (dimensionally stable) |
| Application Temperature | Yes (conforms to standard requirements) |
| Humidity Range | 5–80% |
| Water Vapour Transmission | Low (chloride and carbonation resistance) |
| Water Ratio | 3.0 L |
| Coverage Rate | ≈ 1.08 m² |
| Bed Thickness | Up to ~120 mm |
| Packaging | 20 kg bag |
| Shelf Life | 12 months (unopened, Dry storage) |
Here are some common examples on where RLA Penapatch HB50 Mortar used by our customers.
