MC-Injekt EP — Two-Component Low-Viscosity Epoxy Resin for Structural Crack Injection — Rigid Bonding of Load-Bearing Concrete Cracks in Beams, Columns, Walls, and Slabs

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MC-Bauchemie MC-Injekt EP

A two-component, solvent-free epoxy injection resin that structurally rebonds cracked concrete, restoring the member to near-monolithic strength.

BrandMC-BauchemieCategoryConcrete RepairFormA low-viscosity, two-part epoxy injection resin from MC-Bauchemie that penetrates fine cracks and cures rigid to…

What is it?

A low-viscosity, two-part epoxy injection resin from MC-Bauchemie that penetrates fine cracks and cures rigid to rebond concrete structurally, conforming to EN 1504-5.

Where is it used?

Dormant (non-moving) structural cracks in beams, columns, shear walls, slabs, rafts and water-retaining structures across dry and damp conditions.

Why use it?

It transmits load across a crack again, recovering compressive and tensile capacity so a cracked member behaves close to an uncracked one rather than simply being cosmetically sealed.

How is it applied?

Surface ports are fixed along the crack, the crack face is sealed, then the mixed 4:1 resin is pressure-injected port-to-port until refusal and left to cure.

About MC-Bauchemie MC-Injekt EP

MC-Injekt EP is MC-Bauchemie’s epoxy-based structural injection resin, built for one job that matters a great deal to a repair engineer: putting load back through a crack. When reinforced concrete cracks under overload, shrinkage or thermal movement, the section loses continuity. A rigid epoxy that is thin enough to travel deep into the crack and strong enough to out-perform the surrounding concrete effectively welds the two faces together again. That is exactly what this resin is formulated to do, and it is classified as a force-transmitting (rigid) injection product under EN 1504-5, the European standard that governs structural bonding of concrete.

The chemistry is a bisphenol epoxy resin (Component A) reacted with an amine hardener (Component B), mixed on site at a fixed 4:1 ratio by volume. Once combined it stays workable for roughly 25 minutes per 100 g batch at 20 degrees C, giving crews a realistic window to prime the pump and inject before it begins to gel. It is moisture-tolerant, so it can be used on damp substrates and even cures under dynamic conditions, which is useful on live structures where traffic or plant cannot be fully stopped. In the Indian context this makes it a dependable choice for consultants and applicators handling distressed beams, columns, water tanks and bridge elements, where a genuine structural repair, not a cosmetic fill, is the specified outcome.

The technical insight

The mechanism rests on two properties working together: viscosity and bond. At roughly 310 mPa.s the resin is thin enough to be drawn deep into cracks by injection pressure and capillary action, wetting the crack walls all the way through the section rather than bridging only at the surface. It then cures to a rigid duromer with a compressive strength around 60 MPa and a flexural tensile strength near 45.7 MPa, both comfortably above the tensile capacity of ordinary structural concrete. Because the cured resin is stronger in tension than the parent concrete, any future overstress tends to relocate to fresh concrete rather than reopen the repaired crack. Injection is worked systematically from the lowest port upward, so resin displaces air and fills the void progressively instead of trapping voids. The moisture compatibility is what separates a structural epoxy like this from ordinary adhesives: the amine system still develops full bond on a damp crack face, which is the normal condition inside real concrete rather than a laboratory dry specimen.

Where it is used

  • Structural rebonding of dormant flexural and shear cracks in RCC beams
  • Injection repair of cracked columns and shear walls to restore load path
  • Sealing and strengthening of cracked slabs, rafts and foundation elements
  • Monolithic repair of cracks in water tanks, basements and retaining structures
  • Crack injection in bridge decks, piers and other transport infrastructure
  • Filling of voids and honeycomb pockets adjacent to reinforcement
  • Bonding of hairline to fine cracks under both dry and damp conditions
  • Filling of pre-placed injection hoses in construction joints

Key advantages

  • Low viscosity (approx. 310 mPa.s) drives deep penetration into fine cracks
  • Rigid, force-transmitting cure conforming to EN 1504-5 for genuine structural repair
  • High mechanical performance: approx. 60 MPa compressive and 45.7 MPa flexural tensile strength
  • Moisture-compatible, so it bonds reliably on damp crack faces common in real concrete
  • Cures even under dynamic conditions, allowing repair without fully stopping the structure
  • Solvent-free formulation with a fixed, easy-to-control 4:1 mix ratio
  • Fast hardening keeps site programmes tight and returns members to service quickly
  • Backed by MC-Bauchemie documentation (TDS, DoP) for specification and QA files

Limitations & considerations

  • Rigid by design, so it is unsuitable for live, moving or expansion joints that flex
  • Best suited to dormant cracks; active cracks should be investigated and stabilised first
  • Below +8 degrees C substrate or ambient temperature work must stop, as cure is impaired
  • Application time is short (approx. 25 minutes per 100 g at 20 degrees C), so batching discipline is essential
  • Cured resin can only be removed mechanically; spills and tooling must be cleaned within pot life
  • Not a coating or waterproofing membrane on its own; it treats the crack, not the surface

Selection & best practice

Start with a proper crack survey to confirm the crack is dormant and to map its depth and pattern, because injecting a still-moving crack wastes resin and will re-crack. Rout and clean the crack line, fix surface ports at spacings roughly equal to the member thickness, and seal the crack face and around each port with an epoxy capping paste so pressure builds instead of leaking. Mix only the quantity you can inject within the pot life, stir Components A and B at 4:1 slowly until fully homogeneous, and repot before pumping. Inject from the lowest port and move upward, holding each port until resin appears at the next, then cap and continue. Keep injection pressure moderate and controlled; excessive pressure can propagate secondary cracks or blow the surface seal. Do not work below +8 degrees C, clean tools with MC-Thinner EP within the working time, and allow full cure before removing the surface seal or loading the member.

Specifications

Product type Two-component, solvent-free low-viscosity epoxy injection resin
Standard EN 1504-5 (rigid, force-transmitting injection)
Mixing ratio 4 : 1 by volume (Component A : Component B)
Viscosity approx. 310 mPa.s at 20 degrees C
Density approx. 1.08 kg/dm3
Compressive strength approx. 60 MPa
Flexural tensile strength approx. 45.7 MPa
Application time approx. 25 minutes per 100 g at 20 degrees C
Application temperature +8 degrees C to +35 degrees C

Industry use cases

Commercial & residential buildings

Rebonding cracked RCC beams, columns and slabs after overload, shrinkage or settlement so members recover their design load path.

Water-retaining structures

Structurally sealing cracks in tanks, sumps and basement walls where a moisture-tolerant epoxy can bond damp crack faces.

Bridges & transport infrastructure

Injecting cracks in decks, piers and abutments, with a resin that cures under dynamic traffic-induced conditions.

Industrial & foundation works

Filling cracks and honeycomb pockets in rafts, machine foundations and floors where a rigid, high-strength repair is specified.

Repair & rehabilitation contractors

A documented EN 1504-5 injection resin for tender-driven strengthening jobs that require verifiable structural performance.

Frequently asked questions

Is MC-Injekt EP a structural repair or just a crack sealer?
It is a structural repair. As a rigid, force-transmitting epoxy classified under EN 1504-5, it rebonds the crack faces so the member carries load across the crack again, rather than merely sealing the surface against water.
Can it be injected into damp or wet cracks?
Yes. It is moisture-compatible and develops full bond on damp crack faces, which reflects the real condition inside most concrete. Standing water should still be removed and free-flowing leaks stabilised before injection.
What crack widths can it handle?
Its low viscosity lets it penetrate fine, hairline-scale cracks by injection. Very fine cracks are treated by low-pressure port injection; wider cracks fill readily. A crack survey should confirm the crack is dormant before injection.
Why can’t I use it on an expansion or movement joint?
Because it cures rigid. A joint that continues to move needs a flexible polyurethane resin or an elastomeric sealant; a rigid epoxy in a moving joint will simply crack again. Use it only on dormant cracks.
What is the mixing ratio and how long do I have to work with it?
Components A and B are mixed 4:1 by volume until homogeneous. You then have roughly 25 minutes per 100 g batch at 20 degrees C, so mix only what you can inject and clean tools with MC-Thinner EP within that window.
How is it supplied and can Space Arc deliver Pan-India?
It is a two-component epoxy supplied in combination packs (commonly boxed litre packs and canisters). Space Arc Engineering supplies and, where required, applies it across Delhi NCR and Pan-India, with the manufacturer TDS and Declaration of Performance for your QA file.

How we position MC-Bauchemie MC-Injekt EP

MC-Injekt EP sits in the structural (rigid) end of MC-Bauchemie’s MC-Injekt injection range. Where the crack is live or the joint continues to move, switch to a flexible MC-Injekt polyurethane resin such as MC-Injekt 2300 rather than a rigid epoxy. For surface capping of the crack line and fixing of ports, pair it with an MC epoxy capping paste, and for tool cleaning use MC-Thinner EP (MC-Verdunnung EP). Across our other brands, comparable structural epoxy injection resins include Sika’s Sikadur crack-injection systems and, from Fosroc, the Nitofill EPLV / Conbextra EP family. Consultants specifying to a particular brand standard can be matched to the exact equivalent from our multi-brand shelf.

Preferred brand · Fosroc equivalent

Fosroc Nitofill EPLV — Choose the Fosroc option when the project or client specification is written around the Fosroc/Nitofill system, or when you want a low-viscosity epoxy injection resin backed by Fosroc’s India-wide technical support and documentation.

Compare with Fosroc Nitofill EPLV →

Source MC-Bauchemie MC-Injekt EP for your project

Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.


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