MC-Bauchemie MC-Injekt 2K PU
A rigid two-component polyurethane resin that re-bonds load-bearing cracks in concrete and masonry, working through both dry and damp substrates where epoxy struggles.
What is it?
A two-component, low-viscosity rigid polyurethane (duromer) injection resin from MC-Bauchemie that force-fits and structurally re-bonds cracks in concrete, masonry and natural stone.
Where is it used?
Dormant structural cracks, voids and honeycombs in RCC beams, columns, slabs, basement walls, water-retaining structures, bridges and old masonry — including surfaces that are damp or water-displacing.
Why use it?
It cures to a rigid, high-strength polymer that transmits load across the crack, restoring monolithic behaviour, and it tolerates damp cracks that would defeat a conventional epoxy.
How is it applied?
Metered A+B components are machine-mixed and injected under pressure through packers set along the crack, filling the full section before the resin gels.
About MC-Bauchemie MC-Injekt 2K PU
MC-Injekt 2K PU is MC-Bauchemie’s answer to a problem every rehabilitation engineer eventually meets: a structurally significant crack that has to be re-bonded, but a substrate that will not stay dry long enough for an epoxy to bite. It is a two-component polyurethane system — an isocyanate side and a polyol side — that reacts on mixing into a rigid, force-transmitting duromer resin. Injected under pressure, it penetrates the crack section, displaces residual moisture, and cures into a hardened polymer that knits the two crack faces back together so the member behaves as one again. On our page it is positioned as a rigid 2K PU structural injection resin conforming to the EN 1504-5 injection principle for restoring load transfer across cracks (Principle 4, structural bonding).
What separates it from the flexible PU foams in the same MC-Injekt family is its intent. Foaming grades chase active water and stay elastic; this grade is engineered to go rigid and carry load. That makes it a repair material rather than just a water-stop — you use it where a crack has compromised the structural continuity of concrete, brickwork or stone and you need the section to act monolithically once more. Because it is low in viscosity and water-displacing, it reaches into fine and tight cracks and works on cracks that are merely damp rather than gushing, giving the specifier a genuinely rigid re-bonding option on real-world, moisture-affected structures. Space Arc supplies and applies it as MC-Bauchemie’s authorised distributor and applicator across Delhi NCR and pan-India.
The technical insight
The mechanism turns on two properties working together: rigidity and water tolerance. Epoxy injection resins re-bond cracks superbly, but their chemistry is intolerant of moisture — a wet crack face interferes with cure and adhesion. Polyurethane chemistry is different: the isocyanate group is comfortable in the presence of water, so a PU resin can displace residual moisture and still cure. Most PU injection grades exploit that by foaming and flexing to seal moving, leaking cracks. MC-Injekt 2K PU deliberately does the opposite — it is formulated as a duromer (thermoset) so that, once reacted, it is a hard, high-strength solid rather than an elastic foam. The result is a resin that shares the epoxy’s job of transmitting load across a bonded crack, while keeping the PU’s ability to work through a damp section. Its low mixed viscosity lets it travel deep into narrow cracks under injection pressure before it gels, so the fill is complete through the thickness of the member and not just at the surface. The trade-off is inherent in the rigidity: a rigid re-bond only makes sense on a dormant crack, because a cured rigid resin cannot accommodate continued movement.
Where it is used
- Structural re-bonding of dormant flexural and shear cracks in RCC beams, columns and slabs
- Injection of cracks in basement retaining walls, raft slabs and water-retaining structures
- Filling and consolidating voids, honeycombs and cavities in concrete and masonry members
- Repair of cracks in bridge piers, abutments, beams and deck slabs
- Re-bonding cracks in old brick and natural-stone masonry in heritage and civil structures
- Sealing and strengthening of rigid construction joints where load transfer is required
- Rehabilitation of damp or moisture-affected cracks that rule out epoxy injection
- Restoring monolithic continuity in hydraulic and general civil-engineering structures
Key advantages
- Cures to a rigid, force-transmitting polymer that restores structural load transfer across the crack
- Works on dry and damp substrates, tolerating moisture that would defeat an epoxy resin
- Low mixed viscosity gives deep penetration into fine and tight cracks under injection pressure
- Water-displacing action helps it advance through residual moisture in the crack
- High compressive and tensile strength once cured, suited to structurally loaded members
- Suitable for concrete, masonry and natural stone, widening the range of repairable structures
- Conforms to the EN 1504-5 principle for injection of cracks to restore load transfer
- Supplied and applied by Space Arc as MC-Bauchemie’s authorised distributor, with method-statement support
Limitations & considerations
- Suitable only for dormant (non-moving) cracks — a rigid re-bond will re-crack if the member keeps moving
- Not the right choice for gushing, high-flow active water leaks, where a fast-reacting flexible PU is intended
- Needs a proper crack survey and structural assessment before injection to confirm rigid re-bonding is appropriate
- Two-component system that must be accurately metered and machine-mixed; poor mixing compromises cure and strength
- Injection through packers under pressure is a specialist operation best left to trained applicators
- Isocyanate-based chemistry requires correct PPE, ventilation and handling during application
Selection & best practice
Start with diagnosis, not injection. Survey the crack, confirm it is dormant, and have the structural cause assessed — rigid re-bonding is only valid where movement has stopped. Clean the crack line, then set injection packers at a spacing suited to the section thickness, typically working from the widest point or, on vertical cracks, from the bottom upward. Surface-seal the crack between packers so the resin builds pressure inside the section rather than bleeding out. Meter Components A and B at the specified ratio and mix thoroughly — accurate proportioning and mixing are what deliver the rated strength — then inject through a suitable pump, moving packer to packer until refusal or until resin shows at the next port. Allow full cure, remove packers, and make good the surface. For any pressurised injection, follow the current MC-Bauchemie technical data sheet and safety data sheet for exact ratios, pot life, temperature limits and PPE; Space Arc can provide the TDS and a project-specific method statement.
Specifications
| Product type | Two-component rigid polyurethane (duromer) injection resin |
| Components | Component A (isocyanate) + Component B (polyol), reacted on mixing |
| Cured character | Rigid, force-transmitting solid (not a flexible foam) |
| Viscosity | Low-viscosity, formulated for deep penetration into fine cracks |
| Moisture tolerance | Water-displacing; suitable for dry and damp cracks |
| Suitable substrates | Concrete, masonry and natural stone |
| Crack condition | Dormant (non-moving) structural cracks, voids and honeycombs |
| Standard / principle | EN 1504-5 injection — restoring load transfer across cracks |
| Application method | Pressure injection through packers using metered A+B mixing |
Industry use cases
Commercial & residential RCC
Re-bonding dormant flexural and shear cracks in beams, columns and slabs to restore monolithic behaviour after distress or overload.
Basements & water-retaining structures
Injecting cracks in retaining walls, raft slabs and tanks where the section is damp but movement has stopped and rigid re-bonding is needed.
Bridges & infrastructure
Structural crack repair in piers, abutments, beams and deck slabs, restoring load transfer across cracks on moisture-exposed elements.
Heritage & masonry
Consolidating cracks, voids and open joints in old brick and natural-stone structures where a rigid, deep-penetrating fill re-knits the section.
Hydraulic & civil works
Sealing and strengthening rigid joints and cracks in general civil and hydraulic structures where load must be carried across the repair.
Frequently asked questions
Is MC-Injekt 2K PU an epoxy or a polyurethane?
Can I use it on a crack that is still moving?
Will it work on a wet or damp crack?
How does it compare with an epoxy injection resin like Nitofill LV?
What standard does it work to?
Can Space Arc carry out the injection, not just supply the resin?
How we position MC-Bauchemie MC-Injekt 2K PU
Within the MC-Bauchemie MC-Injekt family, choose by what the crack is doing. MC-Injekt 2K PU is the rigid, force-transmitting grade for structurally re-bonding dormant cracks on dry or damp concrete and masonry. Where the crack is actively leaking water and needs a fast, flexible seal, MC-Bauchemie’s foaming and flexible PU injection grades (the MC-Injekt water-reactive and elastic resins) are the right siblings, and the 2700 / 2700 L rigid duromer resins cover heavier force-transmitting and soil-consolidation work. Across our other brands, Space Arc also stocks Fosroc’s injection range — the epoxy Nitofill LV for structural crack re-bonding on dry sections, and the water-reactive Nitofill UR63 for chasing active leaks — so a specifier can match resin to substrate condition regardless of brand.
Fosroc Nitofill UR63 — Choose the Fosroc PU when the crack is actively leaking and needs a fast, water-reactive seal rather than a rigid structural re-bond; for a dry structural re-bond, Fosroc’s epoxy Nitofill LV is the closer match.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.