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RLA Penapatch HB50 High Build Repair Mortar: A Technical Overview
RLA Penapatch HB50 is a polymer-modified, fibre-reinforced, shrinkage-compensated cementitious mortar designed for vertical and overhead structural repairs. The formulation delivers high build in a single pass with excellent bond to concrete and low permeability to resist chloride ingress and carbonation. Supplied in 20 kg bags, it mixes with ~3.0 L water and exhibits a fresh wet density ~2120 kg/m³. Typical coverage is ~1.85 kg/m² per mm of thickness, enabling predictable estimating and consistent outcomes across Australian job sites (application range 5–35 °C).
55 MPa
28-day compressive strength
Core Features & Specifications
- High build capability: 5–80 mm in a single application (up to 120 mm in small pockets/formwork).
- High strength profile: ~15 MPa (1 day), ~40 MPa (7 days), ~55 MPa (28 days).
- Flexural strength: ~8.5 MPa (28 days) for durable edge retention and impact resistance.
- Low permeability for improved durability against chlorides and carbonation.
- Shrinkage-compensated and dimensionally stable to reduce cracking risk.
- Excellent workability and compaction; simply add water (≈3.0 L per 20 kg).
- Application temperature window: 5–35 °C; internal and external use.
- Coverage guidance: ~1.85 kg/m²/mm (≈1.08 m² at 10 mm per 20 kg bag).
- Colour: Grey; Shelf life: 12 months in unopened bags stored dry.
- Packaging: 20 kg polylined bags.
The RLA Penapatch HB50 Advantage
- Delivers Engineered Certainty in vertical and overhead patches with minimal slump/sag.
- Reduces call-backs thanks to low shrinkage and strong bond to prepared concrete.
- Supports long-term durability where chloride exposure or carbonation is a concern.
- Predictable estimating and less waste using the clear coverage rate and water addition.
- Site-friendly: pre-bagged consistency and water-only mix for fast, repeatable results.
Proactive Troubleshooting
Scenario: Applying over weak, laitance-contaminated concrete
Potential Outcome: Debonding or hollow-sounding patches.
Adheseal Best Practice: Mechanically prepare to sound substrate (e.g., scabbling, grinding, or high-pressure water-blasting). Remove dust, slurry and contaminants. Saw-cut to a minimum depth to avoid feather edges.
Scenario: Over-watering to extend pot life
Potential Outcome: Reduced strength, increased shrinkage and surface dusting.
Adheseal Best Practice: Stick to ~3.0 L water per 20 kg. Mix to a cohesive, non-slump consistency suitable for vertical/overhead application; do not re-temper once setting has begun.
Applications in Practice: Trade Scenarios
For Remedial Contractors (On-site Applicator): Patch repair of spalled columns
The Professional's Challenge
Restore cover to corroded reinforcement on vertical elements without sag, while hitting program deadlines and strength targets.
The Adheseal Solution: Engineered Certainty in Practice
Cut back to sound concrete and clean steel; prime steel where required. Pre-dampen substrate to SSD, then place HB50 at 20–40 mm in one pass. Compact well to encapsulate bars. Finish with float/sponge; cure to prevent rapid moisture loss.
Best Practice Note
Avoid feather edges — saw-cut the perimeter; where depths exceed 80 mm, build in layers or use local formwork/pockets up to 120 mm.
For Builders (Business Owner): Panel edge repairs prior to coating
The Professional's Challenge
Tight finishing window before coating; need consistent edges and minimal shrinkage to avoid telegraphing under paint.
The Adheseal Solution: Engineered Certainty in Practice
HB50’s shrinkage-compensated matrix limits movement across step-downs. Apply 10–20 mm; finish and cure. Once dry and stable, proceed with the selected protective coating system per manufacturer guidance.
Best Practice Note
Respect ambient conditions (5–35 °C). Protect from wind and direct sun; use curing compound or wet hessian where appropriate.
For Specifiers/Engineers: Durability repairs in chloride-exposed assets
The Professional's Challenge
Achieve long-term cover and reduced permeability to mitigate chloride ingress and carbonation risk.
The Adheseal Solution: Engineered Certainty in Practice
HB50’s low permeability and strength development support durable reinstatement of cover. Specify substrate prep to SSD, controlled water addition (~3.0 L/bag), compaction, and curing to standard concrete practice.
Best Practice Note
Document thickness limits (single lift 5–80 mm; up to 120 mm in pockets/formwork) and curing regime aligned to Australian climate zones.
Frequently Asked Questions
What thickness can I apply in one pass on vertical surfaces?
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.
How much water do I add per 20 kg bag?
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.
What is the coverage per bag?
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.
Can I use Penapatch HB50 externally?
Yes. It is suitable for internal and external applications on properly prepared concrete. Protect fresh repairs from rain, sun and wind during early cure.
When can I coat over the repair?
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.
What is the recommended temperature range for application?
Apply between 5–35 °C. In hot or windy conditions, cool materials where possible and implement curing to prevent rapid moisture loss.
Applications & Benefits
| 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 |
Applying RLA Penapatch HB50 High Build Repair Mortar: Enhanced Protocols & Best Practices
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Surface Preparation
Cut back to sound concrete; remove weak/contaminated material. Clean and pre-dampen to SSD. Protect adjacent finishes.
Mechanical key
Scabble, grind or high-pressure water-blast to expose sound aggregate and provide a profile.
Edge detailing
Saw-cut to a minimum depth to avoid feather edges and ensure patch integrity.
Timing: Proceed once the substrate is SSD (no standing water).Pro Tip: Clean reinforcing steel to bright metal and prime if specified. -
Mixing
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.
Water control
Adjust within manufacturer tolerance for placement method; do not over-water.
Slurry bonding coat (optional)
For difficult substrates, prepare a thin bonding slurry and apply wet-on-wet before main placement.
Timing: Use mixed material promptly; do not re-temper once setting commences.Pro Tip: Cool mixing water/materials in hot weather to extend working time. -
Placement & Build
Press firmly into the substrate, compact to eliminate voids, and build to the required thickness.
Thickness guidance
Single pass 5–80 mm vertical/overhead; up to ~120 mm in small pockets or with formwork. Layer for deeper sections.
Finishing
Float/sponge finish once material has firmed sufficiently; avoid over-working the surface.
Timing: Allow adequate stiffening between layers; follow standard concrete practice.Pro Tip: Compact around reinforcement to ensure full encapsulation and bond. -
Curing & Overcoating
Protect fresh repairs from rapid drying, rain and temperature extremes. Implement curing suitable to conditions (e.g., curing compound, damp hessian, or shade).
Coating
Overcoat once the repair has hardened and dried to the coating manufacturer’s requirements. Verify moisture and surface condition before coating.
Timing: Cure immediately after finishing; drying time varies with thickness and climate.Pro Tip: In hot/windy Australian conditions, increase curing measures to prevent plastic shrinkage.
Limitations & Safety
Product Limitations
Not for application below 5 °C or above 35 °C, or onto frozen/ice-laden substrates.
Not suitable for feather-edge finishing; maintain minimum thickness and saw-cut edges.
Do not add cement, lime, or admixtures; water-only addition (~3.0 L/20 kg).
Not intended for direct application to timber, metals or plastics without a suitable system/bonding approach.
Safety & Handling Requirements
Personal Protective Equipment
Wear gloves, safety glasses and a P2/P3 dust mask when handling powder and mixing. Use protective clothing to avoid skin contact.
Ventilation Requirements
Ensure good ventilation during mixing and placement, especially indoors or in confined spaces.
Fire & Handling Precautions
Non-flammable. Avoid generating airborne dust. Store sealed in a cool, dry area away from moisture uptake.
Emergency First Aid
Eyes:
Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing and seek medical advice.
Skin:
Wash with soap and water. Remove contaminated clothing and launder before reuse.
Inhaled:
Move to fresh air and rest. Seek medical attention if symptoms persist.
Swallowed:
Rinse mouth; do not induce vomiting. Seek medical attention immediately.
Seek medical attention immediately in all cases of serious exposure.
RLA Penapatch HB50 High Build Repair Mortar Application Guide
Concrete (vertical/overhead)
Surface Preparation
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).
Primer Requirements
Primer typically not required on well-prepared SSD concrete
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)Reinforcing Steel (within repair)
Surface Preparation
Clean to bright metal; remove rust/scale. Replace severely corroded sections per engineering advice.
Primer Requirements
Primer optional per project specification
If specified, apply an appropriate steel primer/passivator and allow to cure before placing HB50.
Steel passivating primer (as specified)Horizontal concrete patches
Surface Preparation
Prepare to sound concrete and SSD. Maintain minimum thickness; compact to avoid entrapped air.
Primer Requirements
Primer not required on SSD concrete
Where substrate is very smooth, lightly roughen to create a mechanical key.
—Masonry (cementitious)
Surface Preparation
Remove friable material; roughen and clean. Pre-dampen to SSD prior to placement.
Primer Requirements
Primer recommended where suction is high
Use a cementitious bonding slurry or compatible bonding agent per project spec.
Cementitious bonding slurry- Choosing a selection results in a full page refresh.