MC-Bauchemie Nafufill Concrete Repair Mortar
MC-Bauchemie’s fibre-reinforced, shrinkage-compensated PCC/SPCC repair mortars — engineered to restore carbonated and spalled concrete to Class R4 structural grade under EN 1504-3.
What is it?
A single-component, polymer-modified and fibre-reinforced cementitious repair mortar (PCC/SPCC) from MC-Bauchemie’s Nafufill range, available in grades up to Class R4 under EN 1504 Part 3. The flagship Nafufill KM 250DS-IN carries dual shrinkage compensation and hits 55 N/mm2 at 28 days.
Where is it used?
Structural and non-structural repair of reinforced concrete — bridges, tunnels, dockyards, water-retaining structures, industrial buildings and any spalled, carbonated or chloride-attacked concrete needing reinstatement.
Why use it?
It rebuilds lost concrete section with a statically allowable, carbonation-resistant and chloride-proof mortar that bonds monolithically to the parent substrate and protects embedded steel — a compliant, engineered alternative to site-batched patch concrete.
How is it applied?
Applied by hand or wet spray onto a pre-wetted, saturated-surface-dry substrate over an MC bond coat, from 10 mm minimum up to 50 mm per pass (80 mm total), then floated and cured for three days.
About MC-Bauchemie Nafufill Concrete Repair Mortar
MC-Bauchemie’s Nafufill range is one of the most widely specified concrete-replacement systems in the repair-and-rehabilitation trade, and Space Arc supplies it across Delhi NCR and Pan-India for projects where a genuine EN 1504-3 mortar is a contractual requirement rather than a nice-to-have. Unlike a bag of site-mixed sand-cement, Nafufill is a factory-blended, polymer-modified and fibre-reinforced dry mortar that arrives with a declared performance class — from Nafufill LM at R1, through KM 220 (R2) and KM 230 (R3), up to the fully structural KM 250DS-IN at R4. That laddered range lets a consultant match the mortar to the actual load case instead of over- or under-specifying, which is exactly the kind of decision that separates a repair that survives the next monsoon cycle from one that debonds within a season.
The flagship Nafufill KM 250DS-IN is a one-component PCC/SPCC concrete replacement built for structural reinstatement of deteriorated members. It is statically allowable, carbonation resistant and chloride-proof, and it satisfies the exposure classes an Indian structural engineer actually writes into a spec — XC1 to XC4 for carbonation, XD and XS for chlorides, XF for freeze-thaw and XA for chemical attack under DIN 1045-2 / EN 206. Crucially, it also works as an anode-embedding and repair mortar under EN 12696 for cathodic-protection schemes, so it fits both conventional patch repair and the more demanding corrosion-management jobs on jetties, flyovers and effluent structures.
The technical insight
The engineering story behind Nafufill KM 250DS-IN is its dual shrinkage compensation. Ordinary repair mortars fail at the bond line because they shrink as they cure while the surrounding concrete does not — that differential builds tensile stress at the interface, opens micro-cracks and eventually peels the patch. Nafufill counters shrinkage in both the plastic and hardened phases, so the repair stays dimensionally stable and keeps its grip on the parent concrete. The polymer modification densifies the matrix and refines the pore structure, which is why the mortar records a carbonation depth of 0 mm at 90 days and resists chloride ingress — the two mechanisms that drive reinforcement corrosion in the first place. Fibre reinforcement holds the fresh mortar together during vertical and overhead placement and controls plastic-settlement cracking. The result is a repair layer that behaves as a monolithic extension of the substrate — sharing load, matching thermal movement and shielding the rebar — rather than a cosmetic skim sitting on top of it.
Where it is used
- Structural reinstatement of spalled, carbonated or delaminated reinforced concrete columns, beams and soffits
- Repair of chloride- and de-icing-salt-attacked concrete in marine, coastal and dockyard structures
- Rehabilitation of tunnels, bridges and flyover elements under dynamic and non-dynamic loading
- Reprofiling and section restoration of water-retaining and effluent-treatment structures
- Vertical and overhead patch repair applied by hand or wet-spray without shuttering
- Anode-embedding and repair mortar for cathodic-protection schemes under EN 12696
- General-building and civil concrete repair where an EN 1504-3 compliance class is specified
- Non-structural levelling and fine filling using the lower-class Nafufill grades (LM, KM 220, KM 230)
Key advantages
- Full EN 1504-3 laddered range from R1 to R4, so the mortar can be matched to the real load case
- Class R4 structural grade (KM 250DS-IN) reaching 55 N/mm2 compressive strength at 28 days
- Dual shrinkage compensation minimises debonding risk at the repair interface
- Carbonation depth of 0 mm at 90 days and chloride-proof — attacks the root causes of rebar corrosion
- Single-component: gauged with water on site, no field batching of polymers or aggregates
- Fibre reinforcement supports thick vertical and overhead placement up to 50 mm per pass
- Applies by hand or wet spray, suiting both small patch jobs and large-area machine application
- Doubles as an anode-embedding mortar for cathodic-protection works under EN 12696
Limitations & considerations
- Cementitious system — needs a pre-wetted, saturated-surface-dry substrate and three-day moist curing, so it is not a rapid-turnaround overnight repair
- Requires an MC bond coat (Nafufill KMH or an MC bonding agent) for hand application; skipping it compromises adhesion
- Application restricted to substrate and air temperatures between +5 and +35 degrees C
- Minimum 10 mm layer thickness per pass means it is not suited to feather-edging or very thin skims — use a fine mortar or the appropriate lower grade instead
- Deteriorated reinforcement must first be de-rusted to Sa 2 and, where needed, protected with a separate corrosion-protection coat
- Shelf life is limited to 9 months in unopened packaging and the powder must be kept dry, off the ground and out of direct sun
Selection & best practice
Start by cutting back to sound concrete and removing every trace of unsound or contaminated material; exposed reinforcement should be de-rusted to a Sa 2 blast standard and, where corrosion is active, treated with an MC corrosion-protection coat before mortar goes on. Pre-wet the substrate thoroughly so it is saturated but surface-dry — slightly damp with no standing water — at the moment of application. For hand placement, apply an MC bond coat (Nafufill KMH or an MC Solid Range bonding agent) and work the mortar in while it is still tacky. Mix each 30 kg bag with 4.5 to 5.1 litres of clean water (roughly 15 to 17 percent) in a forced-action or slow double mixer for at least five minutes; do not hand-mix or gauge partial bags. Build up in layers of 10 mm minimum to 50 mm maximum per pass, keeping within an 80 mm total, then float or sponge to the required finish. Protect the fresh repair from sun and wind and cure it for three days to develop full strength and durability.
Specifications
| Product type | Polymer-cement concrete (PCC/SPCC), single-component |
| EN 1504-3 class | Class R4 (Nafufill KM 250DS-IN); range spans R1 to R4 |
| Compressive strength | 30 N/mm2 (48 h) / 42 N/mm2 (7 d) / 55 N/mm2 (28 d) |
| Flexural strength | >5 N/mm2 at 28 days |
| Tensile strength | >1.5 N/mm2 at 28 days |
| Carbonation depth | 0 mm at 90 days |
| Layer thickness | 10 mm min / 50 mm max per pass; 80 mm total |
| Added water | 4.5 to 5.1 litres (15 to 17%) per 30 kg bag |
| Packaging / shelf life | 30 kg sacks; 9 months in unopened packaging |
Industry use cases
Bridges & flyovers
Reinstating spalled soffits, piers and crash barriers on dynamically loaded structures where a statically allowable R4 mortar is mandated.
Marine & dockyards
Repairing chloride-attacked jetties, quay walls and coastal RCC using a chloride-proof mortar suited to XS and XD exposure classes.
Water & effluent structures
Section restoration of tanks, channels and STP/ETP concrete that must resist carbonation and aggressive chemical exposure (XA classes).
Tunnels & infrastructure
Hand or wet-spray repair of tunnel linings and civil concrete needing high carbonation resistance and reliable overhead build.
Industrial buildings
Structural and non-structural patch repair across the Nafufill grade ladder, matching R2/R3/R4 mortars to the member being repaired.
Frequently asked questions
Is Nafufill an epoxy mortar or a cementitious one?
Which Nafufill grade do I specify for structural repair?
What compressive strength does it reach?
How thick can it be applied in one pass?
Do I need a separate bond coat and corrosion protection?
Can Space Arc supply it across India with application support?
How we position MC-Bauchemie Nafufill Concrete Repair Mortar
Within MC-Bauchemie’s own system, Nafufill is best specified as a family rather than a single SKU: Nafufill LM (R1) for lightweight non-structural fill, KM 220 (R2) and KM 230 (R3) for progressively more demanding surface repair, and KM 250DS-IN (R4) for full structural reinstatement — paired with Nafufill KMH or an MC bonding agent as the bond coat and MC’s corrosion-protection range for treating exposed steel. For coating and protecting the completed repair, MC’s Emcephob and MC-DUR product lines cover anti-carbonation and chemically resistant finishes. Where a project is standardised on the Fosroc system instead, the equivalent hand-applied repair mortars are Fosroc’s Renderoc family (see below), and Space Arc can supply either system depending on the specifier’s preference and the approved-vendor list on the job.
Fosroc Renderoc HB — A specifier standardised on the Fosroc concrete-repair system may prefer Renderoc HB for hand-applied high-build vertical and overhead patch repair, though it is a Class R2 mortar and does not match the R4 structural grade of Nafufill KM 250DS-IN.
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