About Fosroc Conbextra EP 150

Fosroc Conbextra EP 150 sits at the deep-gap, high-volume end of the Conbextra epoxy grouting family. It is a solvent-free epoxy resin system supplied as three pre-batched components – a base resin, a liquid hardener and a sack of specially graded inert fillers – all delivered in the correct proportions so that the entire pack is mixed together on site with nothing else added. The defining feature is its free-flow consistency combined with the ability to fill gaps from roughly 10 mm right up to 150 mm in a single pour, which is well beyond the reach of thinner epoxy grouts such as Conbextra EP 10. That makes it the natural choice for installations where the void beneath a heavy base plate is deep, the loads are punishing, and the environment is chemically hostile. For contractors and consultants in India, EP 150 answers a specific brief: where cementitious shrinkage-compensated grouts cannot deliver the chemical resistance or the fatigue performance demanded by reciprocating and rotating plant, and where the gap is simply too deep for a standard precision epoxy. Typical hosts are reciprocating machinery, testing equipment, heavy crane and transporter rails, high-speed turbines, centrifuges and drop forges – the kind of equipment found in steelworks, refineries, electroplating shops and chemical processing plants. The grout’s extended working time is deliberately tuned for the large-volume pours and elevated ambient temperatures common on Indian sites, giving crews enough open time to complete a deep pour before the mix begins to gel. Once cured it behaves as a rigid, dense, low-creep bedding medium that transmits machine loads uniformly into the foundation while resisting the repetitive shocks that would loosen or fatigue a weaker bed. As an authorised Fosroc distributor and applicator serving Delhi NCR and pan-India, Space Arc Engineering supplies EP 150 alongside method-statement support so that specifiers get both the right product and the right placement discipline for deep-gap epoxy grouting.

The technical insight

The performance of Conbextra EP 150 rests on the balance between its filled epoxy matrix and its low coefficient of thermal expansion. Cured at 35 degrees C, it develops a compressive strength of around 100 N/mm2 at 7 days (ASTM C579), with the official data showing 78/92/100/105 N/mm2 at 1/3/7/28 days when cured at 24 degrees C and 82/96/105/110 N/mm2 at 36 degrees C – confirming that warmer curing accelerates early strength, an advantage on Indian summer sites. Tensile strength is 16 N/mm2 (ASTM C307, 7 day) and flexural strength is 30 N/mm2 (ASTM C580, 7 day), with a modulus of elasticity of approximately 11 kN/mm2 that keeps the bed stiff enough to seat machinery without excessive deflection. The mixed grout is dense at 2040 kg/m3 (specific gravity around 2.04), and its linear coefficient of thermal expansion of 42 x 10-6 mm/mm/degree C is low for a filled epoxy – this matters because a high-expansion epoxy in a deep, unrestrained section is prone to cracking and peeling under cyclic temperature swings. The practical lever for the installer is pot life: about 150 minutes at 24 degrees C falling to 105 minutes at 35 degrees C, with a gel time of 100 minutes at 38 degrees C (ASTM D2471). Because every epoxy generates an exotherm, the depth of a single lift, the ambient temperature and the pour rate must be planned together – deep, hot pours shorten the usable window, so head-box pouring from one side in a continuous operation is essential to keep the flowing front moving (flow is 200 mm at 24 degrees C) and to expel entrapped air before the mass starts to gel.

Where it is used

• Bedding of heavy reciprocating machinery base plates where dynamic and impact loads demand a fatigue-resistant grout
• Grouting under high-speed turbines, centrifuges, compressors and rotating equipment requiring low creep and a rigid bed
• Deep-gap grouting beneath crane rails, transporter rails and drop forges in steel plants
• Anchoring and bedding of machinery in refineries, electroplating works and chemical plants where chemical spillage is likely
• Filling deep voids of 10-150 mm in a single pour where cementitious grouts or thin epoxy grouts are unsuitable
• Test-bed and dynamometer foundations where high static load and vibration are present

Key advantages

• Bridges deep gaps from approximately 10 mm up to 150 mm in a single continuous pour
• Low creep under sustained load and high resistance to repetitive dynamic and impact loading
• Non-shrink behaviour ensures complete contact and bond across the full base-plate area
• High compressive (around 100-110 N/mm2), tensile (16 N/mm2) and flexural (30 N/mm2) strengths
• Solvent-free and supplied as a pre-batched whole-pack system – no site proportioning or extra additions
• Extended working time suited to large-volume pours and high ambient temperatures
• Resists oil, grease, fats, mild acids and alkalis, fresh water and sea water

Limitations & considerations

• Not a cementitious grout – higher material cost than Conbextra GP/HF, so reserve for genuine epoxy duties
• Exothermic during cure; deep single lifts in high ambient temperatures shorten pot life and risk excessive heat build-up
• Unrestrained deep sections exposed to cyclic temperature change can crack or peel – careful shuttering to minimise exposed shoulders is required
• Cure must proceed above 5 degrees C for the grout to reach full properties
• Substrate must be clean, sound, dry and oil-free; concrete should be at least 28 days old and steel grit-blasted for proper bond
• Pot life is temperature-sensitive (about 150 min at 24 C, 105 min at 35 C) – mixing and placing must be planned and continuous
• For chemical exposure beyond mild acids/alkalis or for concentrated solvents, the specific chemical should be checked with Fosroc/Space Arc first

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Conbextra EP 150

Within the Fosroc Conbextra family, EP 150 is the deep-gap, free-flow epoxy specialist: use it where the void is 10-150 mm and the machinery is heavy, vibratory or chemically exposed. For thin epoxy sections (around 10 mm and below) the right product is Conbextra EP 10, while ultra-high-strength precision needs in the 10-100 mm band point to Conbextra EP 65 Plus. Where chemical resistance and epoxy-grade fatigue performance are not required, the economical cementitious choices are Conbextra GP/GP2 (general-purpose shrinkage-compensated, up to ~100 mm) and Conbextra HF (high-flow, up to ~125 mm) – these should be specified for routine structural and machine grouting to keep cost down, reserving EP 150 for genuine epoxy duties. Among competing brands available in India, credible epoxy-grout alternatives include Sika’s SikaGrout epoxy precision grouts and Sikadur range, MBS Engineering’s epoxy grouts, Dr. Fixit (Pidilite) Pidigrout EP epoxy grouts, and STP epoxy grouting systems; cementitious equivalents to the GP/HF line include SikaGrout cement grouts and Dr. Fixit Pidigrout NS/GP. Space Arc Engineering, as an authorised Fosroc distributor and applicator across Delhi NCR and pan-India, recommends EP 150 specifically for deep-gap, high-dynamic-load and chemically aggressive machine-grouting applications, and can advise on selecting between the epoxy and cementitious Conbextra grades for a given foundation, load case and exposure.

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