Fosroc Conbextra EPGP
Solvent-free, three-component epoxy resin grout engineered for free-flow placement into 20-80 mm gaps beneath dynamically and mobile-loaded machinery, with high chemical resistance and very low permeability.
What is it?
A solvent-free, three-component (epoxy base + hardener + pre-graded aggregate) free-flow epoxy resin grout from Fosroc, designed for grouting gap widths of 20-80 mm under heavily and dynamically loaded equipment.
Where is it used?
Machine and turbine foundations, crane and gantry rails, compressor and pump bedplates, structural baseplates, crusher and mill anchors, and pile-top encapsulation across power, steel, cement, petrochemical and heavy-fabrication plants.
Why use it?
It delivers 80 N/mm2 compressive, 17 N/mm2 flexural and 12 N/mm2 tensile strength at 7 days with nil water penetration and negligible chloride permeability, so it carries vibration, impact and chemical exposure that cementitious grouts cannot.
How is it applied?
The whole hardener pack is blended into the base, the graded aggregate is added in a forced-action mixer for 2-3 minutes, and the grout is poured continuously from one side within its pot life into leak-proof formwork, maintaining a hydrostatic head.
About Fosroc Conbextra EPGP
Fosroc Conbextra EPGP is a multi-purpose, solvent-free epoxy resin grout supplied as a three-component system: an epoxy base, an epoxy hardener and a bag of specially graded aggregate, all pre-proportioned for whole-pack mixing on site. It sits in the upper tier of the Conbextra grout family, above the cementitious Conbextra GP/HF range and alongside dedicated epoxy machine grouts such as Conbextra EP10 and EP75. The product is built for situations where the long-term mechanical performance, low permeability and chemical resistance of the cured grout must be of the highest order, and where the gap to be filled is comparatively deep at 20-80 mm. For engineers and consultants in India specifying foundations for rotating or reciprocating equipment, EPGP is the answer when the application combines a meaningful annular or under-plate gap with sustained dynamic loading. Because it is solvent-free, it can be used in enclosed plant rooms and pits without the ventilation and flammability concerns of solvented systems, although the associated Nitoprime 25 steel primer and Fosroc Solvent 102 cleaner are flammable and must be handled accordingly. The whole-pack philosophy is deliberate: no site water, sand or filler is added, which removes the single largest source of on-site grout variability and guarantees that the placed material reproduces the laboratory-tested properties. Supplied in 14 litre packs, EPGP is positioned for heavy-duty industrial grouting rather than thin bedding, and it is the natural specification where free-flow placement, high early strength for fast plant commissioning, and resistance to acids, alkalis, water and frost all have to coexist in one pour.
The technical insight
The defining characteristic of an epoxy grout like Conbextra EPGP is that load is transferred through a continuous polymer-bonded aggregate matrix rather than a hydrated cement paste, which is why it tolerates vibration and dynamic stress that would micro-crack a cementitious grout. The published 7-day figures of 80 N/mm2 compressive (BS 6319 Part 2), 17 N/mm2 flexural (BS 6319 Part 3) and 12 N/mm2 tensile (BS 6319 Part 7) are notable for the high flexural-to-compressive and tensile-to-compressive ratios typical of resin systems; that flexural reserve is what resists edge-lifting and fatigue under repeated impact at the bond line. EPGP is formulated for relatively deep gaps (20-80 mm) where the lower exotherm of an aggregate-filled epoxy is an advantage over neat or lightly filled resins, which can over-heat and shrink in thick sections. Flow data confirm its free-flow design: under a 100 mm head at 35 degrees C it travels around 1000 mm through a 35 mm gap and 1800 mm through a 70 mm gap, so a single carefully fed pour from one side can fill long base-plate voids without air entrapment. Pot life is the practical constraint, dropping from about 2 hours at 25 degrees C to roughly 1 hour at 35 degrees C, so Indian site temperatures directly govern batch sizing and pour logistics; above 35 degrees C Fosroc requires special procedures. Durability is underwritten by nil water penetration after 7 days (DIN 1048 Part 5:1991) and negligible rapid chloride permeability (AASHTO T277-83), which together make the cured grout effectively impermeable and part of the waterproofing envelope around a foundation.
Where it is used
- Grouting machine and equipment baseplates with 20-80 mm gaps under dynamic, vibrating or mobile loads
- Heavy-duty support and bedding of large structural elements and steel columns
- Foundations for compressors, pumps, turbines, fans and other rotating equipment
- Crane rails, gantry tracks and crusher/mill anchor systems subject to impact loading
- Pile-top encapsulation and load transfer at pile heads
- Underplate grouting where high chemical resistance and very low permeability are specified
- Grouting in chemical, marine and effluent environments exposed to acids, alkalis, water or frost
Key advantages
- High flexural strength and adhesion give excellent fatigue performance under dynamic and impact loading
- High early strength allows minimum downtime and early commissioning of plant and machinery
- Free-flow consistency fills deep 20-80 mm gaps and long voids from a single pour without vibration
- Resists a wide range of chemicals, acids and alkalis, plus water and frost attack
- Very low / nil water penetration and negligible chloride permeability for long-term durability
- Solvent-free formulation suits enclosed plant rooms and pits
- Pre-proportioned whole-pack system removes site batching errors and reproduces tested properties
Limitations & considerations
- Designed for gap widths of 20-80 mm; not intended for thin bedding or very large mass pours in a single lift
- Pot life is short and temperature-sensitive (about 2 hrs at 25C, 1 hr at 35C); above 35C special procedures are required
- Continuous, well-organised placement is essential as stiffened material must be discarded after pot life
- Considerably more expensive than cementitious Conbextra GP/HF grouts, so reserved for genuinely demanding duty
- Some users are sensitive to epoxy resins; gloves, barrier cream and eye protection are required
- Steel base plates should be primed with Nitoprime 25 and surfaces must be substantially dry and free of standing water
- Associated primer and cleaning solvent are flammable and need ventilation and fire precautions
Selection & best practice
Cut back defective or laitance-affected concrete to a sound base and blow bolt pockets clean; the foundation must be free of oil, grease and loose material and substantially dry with no standing water. Where steel base plates may be left exposed before grouting, prime the underside and edges with Nitoprime 25 to prevent rust and ensure bond. Build leak-proof formwork using foam strip or mastic sealant, keeping the gap to roughly 75 mm on the pouring side and 25 mm on the opposite side for underplate work, with flank formwork tight to the plate edge and air-relief holes at high spots. Pour the full hardener into the base, mix until homogeneous, then add the entire aggregate in a forced-action mixer for 2-3 minutes until uniform in colour, never adding extra water or filler. Place from one side only, maintaining a continuous grout front and hydrostatic head to avoid air entrapment, and size each batch to the time available within the pot life for the actual site temperature. Clean tools immediately with Fosroc Solvent 102 before the grout hardens.
Specifications
| Product type | Multi-purpose, solvent-free epoxy resin grout (three-component: base + hardener + graded aggregate) |
| Designed gap width | 20-80 mm |
| Compressive strength | 80 N/mm2 at 7 days (BS 6319: Part 2) |
| Flexural strength | 17 N/mm2 at 7 days (BS 6319: Part 3) |
| Tensile strength | 12 N/mm2 at 7 days (BS 6319: Part 7) |
| Pot life | 2 hrs at 25C; 1 hr at 35C |
| Maximum flow (100 mm head @ 35C) | 1000 mm through a 35 mm gap; 1800 mm through a 70 mm gap |
| Water penetration | Nil after 7 days (DIN 1048: Part 5:1991) |
| Rapid chloride permeability | Negligible (AASHTO T277-83) |
| Mixing | Whole-pack only; no water, sand or filler added on site |
| Pack size | 14 litre packs |
| Ancillary products | Nitoprime 25 steel primer (1 & 4 L); Fosroc Solvent 102 cleaner (5 L) |
| Shelf life | 12 months in dry, cool, unopened original packaging |
| High-temperature working | Above 35C special procedures required – consult Fosroc |
Industry use cases
Power & energy
Grouting turbine, generator, fan and compressor baseplates on dynamically loaded foundations in thermal and captive power plants, where high flexural strength resists vibration fatigue.
Steel & metals
Bedding rolling-mill stands, crane and gantry rails and crusher anchors that take continuous impact and mobile loads in integrated steel plants.
Cement & minerals
Anchoring mills, kiln drives and crusher foundations where the grout must survive both vibration and chemically aggressive dust and washdown conditions.
Petrochemical & chemical
Pump and compressor skids in process areas demanding resistance to acids, alkalis and spillage, with the nil-permeability cured grout acting as part of the spill containment.
Infrastructure & marine
Pile-top encapsulation and heavy structural support in port, bridge and coastal works where chloride resistance and low permeability are essential.
Heavy fabrication & EPC
Free-flow underplate grouting of large machinery on EPC projects with 20-80 mm gaps, allowing fast commissioning through high early strength.
Frequently asked questions
Is Fosroc Conbextra EPGP an epoxy or a cementitious grout?
What gap widths and strength can I expect from Conbextra EPGP?
How long is the working time (pot life) on an Indian site?
Do I need to prime the steel base plate before grouting?
How is Conbextra EPGP supplied and how do I mix it?
When should I choose EPGP over Conbextra EP10, EP75 or a cementitious grout?
Can Space Arc Engineering supply EPGP across India with technical support?
How we position Fosroc Conbextra EPGP
Within the Fosroc range, Conbextra EPGP is the deep-gap, dynamically-loaded epoxy grout: it overlaps in chemistry with Conbextra EP10, EP75 and EP300 but is specified where the 20-80 mm gap and chemical/permeability demands rule out both thinner precision epoxy grouts and the economical cementitious Conbextra GP, GPC and HF families. It is naturally paired with Nitoprime 25 (steel primer) and Fosroc Solvent 102 (cleaner), and on the same foundation contractors often use Conbextra GP for non-critical grouting and Nitofill or Conbextra EP injection resins for crack repair. Against the wider market, credible alternatives include Sika Grout-3200 and SikaGrout-318 epoxy grouts, MC-Bauchemie (MBS) Emcekrete/Ucrete-type epoxy systems, STP (Shalimar/STP) epoxy machine grouts, BASF/MBS Masterflow epoxy grouts, and Dr. Fixit/Pidilite Roff epoxy grouts for lighter duty; cementitious competitors such as Sika MonoTop and Dr. Fixit Pidicrete cover only the lower-performance end and are not direct substitutes for dynamic, chemically-exposed foundations. Honestly assessed, EPGP’s strengths are its proven BS 6319 mechanical figures, free-flow placement in deep gaps and impermeability; its trade-offs are cost and a temperature-sensitive pot life, so it should be reserved for foundations where vibration, impact or chemical exposure genuinely justify an epoxy system over a cementitious grout.
Related Grouts & Anchors products
Source Fosroc Conbextra EPGP for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.