Fosroc Conbextra EP10
Solvent-free, two-component epoxy resin grout that reaches 80 N/mm² in 7 days — built for precision baseplate grouting under dynamic machinery and for injecting cracks and honeycombs from 0.25 mm.
What is it?
A high-strength, solvent-free epoxy resin grout from Fosroc’s Conbextra range. It is an all-liquid, two-component system (base plus hardener) supplied pre-proportioned for whole-pack mixing, and flows freely into gaps of 0.25 mm to 10 mm.
Where is it used?
Under turbine and machinery baseplates, crane and transporter rails, and in steelworks, refineries, chemical and electroplating plants — plus injection of cracks, honeycombs and construction joints in high-strength concrete.
Why use it?
Non-shrink bearing contact, 45 N/mm² compressive strength within a day and 80 N/mm² at 7 days, good general chemical resistance, and one product that handles both precision grouting and resin injection.
How is it applied?
Mix the full pack for 2-3 minutes, then pour from one side under leak-proof formwork with a maintained hydrostatic head. For crack repair, inject through 8-10 mm nipples with a suitable pump until resin shows at the adjacent port.
About Fosroc Conbextra EP10
Conbextra EP10 sits at the top end of Fosroc’s grouting range, specified where a cementitious grout simply cannot deliver the required strength, chemical resistance or fatigue performance. It is a two-component epoxy system with no fillers and no solvent — just a resin base and hardener supplied in matched proportions in a 1 litre pack. Because the mixed material is entirely liquid, it flows into clearances as tight as 0.25 mm and up to 10 mm, wetting out both the concrete foundation and the underside of a steel plate to give full surface-to-surface bearing.
The same low viscosity makes it a practical injection resin. Indian contractors routinely use Conbextra EP10 through nipple-and-pump systems to reinstate cracks, honeycombed pockets and construction joints between 0.25 mm and 9 mm wide in high-strength concrete. Specification clauses typically call for a minimum 7-day compressive strength of 80 N/mm², which the product meets at standard curing. Space Arc Engineering stocks and supplies Conbextra EP10 across Delhi NCR and pan-India, with applicator support for both grouting and injection work.
The technical insight
The performance comes from the chemistry of an unfilled thermoset. When the hardener is folded into the epoxy base, the two react and cross-link into a rigid three-dimensional polymer network — no water is involved, so there is no bleed, no plastic settlement and no drying shrinkage. That is why the grout holds full contact under a baseplate instead of pulling away as it hardens. The cured matrix is far stronger than the concrete around it — 80 N/mm² in compression, 40 N/mm² in flexure and 20 N/mm² in tension at 7 days — so repetitive dynamic loads from turbines or reciprocating machinery pass through the grout without fatigue cracking at the bearing interface. The dense cross-linked structure is also what gives the grout its general chemical resistance in spillage-prone plants. The trade-off is exothermic, confined curing: the resin must be restrained by formwork or the surrounding void, because unrestrained shoulders of grout can crack as the reaction proceeds.
Where it is used
- Underplate grouting beneath substantial structural elements and steel baseplates
- Machine foundation grouting under dynamic loads — turbines, compressors and reciprocating plant
- Crane rail and transporter rail grouting for heavy material-handling systems
- Heavy industrial installations in steelworks, refineries, chemical plants and electroplating works
- Structural infill of narrow voids where very high strength is essential
- Low-pressure injection of cracks in high-strength concrete members (0.25-9 mm)
- Filling honeycombs, cavities and construction joints by resin injection
Key advantages
- Reaches 45 N/mm² compressive strength in 1 day, allowing early plant commissioning and minimal downtime
- 7-day compressive strength of 80 N/mm² — well above the concrete it sits on
- Non-shrink behaviour maintains full bearing contact between foundation and plate
- Free-flowing all-liquid consistency fills 0.25-10 mm gaps without vibration
- One material covers both precision grouting and crack injection on the same site
- Good general chemical resistance for spillage-prone industrial floors and plinths
- Pre-proportioned whole-pack mixing eliminates site batching errors
- Proven under repetitive dynamic loading, not just static loads
Limitations & considerations
- Designed for 0.25-10 mm gaps only — thicker pours need a different grout grade, such as a cementitious Conbextra
- Must be placed in a restrained situation; unrestrained shoulders and exposed plinth edges can crack as the resin cures
- Pot life is about 50 minutes at 27°C and drops sharply in Indian summer heat, so batches must be planned and poured without interruption
- Substrates must be completely dry immediately before placement — damp foundations compromise the bond
- Rigid once cured, so it is not suitable for live or moving cracks
- Epoxy resins can sensitise skin; gloves, goggles and barrier cream are required, and hardened resin cannot be removed with solvent from skin
Selection & best practice
Preparation decides the result. Cut back defective or laitance-affected concrete to a sound base, remove oil and grease, and blow bolt pockets clean with compressed air. If steel baseplates will wait before installation, prime their underside and edges with Nitoprime 25 after cleaning the steel bright. Build leak-proof formwork — foam strip or mastic under the boards — keeping roughly 75 mm clearance on the pouring side and 25 mm opposite, and use a feeding hopper to maintain a hydrostatic head. Pour the entire hardener can into the base container and mix 2-3 minutes to a uniform colour; never split packs. Pour from one side only so air is driven ahead of the grout front. For injection, drill 8-10 mm holes along the crack, fix GI or PVC nipples with epoxy putty, seal the crack face, and pump until resin appears at the adjacent nipple. Above 35°C, shade the packs, keep equipment cool and avoid midday application. Clean tools immediately with Nitoflor Sol.
Specifications
| Form | Two-component, solvent-free, all-liquid epoxy resin grout (base + hardener) |
| Gap range (grouting) | 0.25 mm to 10 mm |
| Injection range (cracks/voids) | 0.25 mm to 9 mm |
| Compressive strength | 45 N/mm² @ 1 day; 60 N/mm² @ 3 days; 80 N/mm² @ 7 days |
| Tensile strength | 20 N/mm² @ 7 days |
| Flexural strength | 40 N/mm² @ 7 days |
| Pot life | Approx. 50 minutes @ 27°C |
| Density (mixed) | Approx. 1050 kg/m³ |
| Supply / shelf life | 1 litre pack; 12 months stored below 35°C |
Industry use cases
Power & Heavy Engineering
Grouting turbine, compressor and generator baseplates where repetitive dynamic loads would fatigue an ordinary grout — with next-day strength that keeps commissioning schedules intact.
Steel Plants & Refineries
Bearing plates, equipment plinths and spillage-zone grouting where acids, oils and process chemicals attack cementitious materials over time.
Infrastructure & Metro
Resin injection of dormant cracks, honeycombed pockets and construction joints in high-strength structural concrete on bridges, stations and precast elements.
Cement & Manufacturing
Re-grouting of mills, crushers and reciprocating machinery during shutdowns, where the 1-day strength of 45 N/mm² shortens outage windows.
Ports & Material Handling
Crane rail and transporter rail grouting where impact and rolling loads demand a non-shrink, high-strength bedding layer.
Frequently asked questions
When should I specify Conbextra EP10 instead of a cementitious grout like Conbextra GP2?
Can Conbextra EP10 be used for crack injection?
How quickly can machinery be re-commissioned after grouting?
Can I mix part of a pack for small jobs?
How does site temperature affect application in India?
Do steel baseplates need a primer before grouting?
How we position Fosroc Conbextra EP10
Conbextra EP10 is the precision, thin-gap epoxy option within Fosroc’s grouting family. For general-purpose baseplate grouting at larger clearances under mainly static loads, the cementitious Conbextra GP2 is the workhorse alternative at a lower cost per litre. Pair EP10 with Nitoprime 25 where steel plates are prepared ahead of installation, and keep Nitoflor Sol on site for tool cleaning. For bonding fresh repairs to old concrete around the same works, Nitobond EP is the usual companion. Space Arc also supplies comparable high-strength epoxy grouts from Sika and MC-Bauchemie for projects standardised on those systems — talk to us about matching the specified strength class rather than forcing a brand swap.
Related Sealants & Joint Treatment products
Source Fosroc Conbextra EP10 for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.