Conbextra EP65 Plus: Ultra High Strength Epoxy Grout

Product Overview

Conbextra EP65 Plus is a rapid hardening, ultra high strength epoxy grout manufactured by Fosroc. It is designed as a precision, heavy-duty multi-purpose epoxy grout for specialized engineering applications. The product is supplied as a two-component system consisting of epoxy resin incorporating inert fillers and a hardener, which combine to produce a highly fluid grout suitable for demanding construction and industrial environments.

Key Technical Specifications

Physical Properties

Conbextra EP65 Plus is supplied in 14-litre two-component, pre-weighed packs, which facilitate convenient handling and ensure consistent proportioning. The product features:

• Color (mixed): Dark grey
• Cured density: 1840 kg/m³
• Minimum thickness: 10mm
• Maximum thickness: 100mm (single pour applications)

Compressive Strength

The product demonstrates exceptional compressive strength development across varying temperatures:

Cure Time	10°C	23°C	30°C	40°C
2 hours	0 MPa	40 MPa	50 MPa	65 MPa
3 hours	5 MPa	70 MPa	80 MPa	90 MPa
4 hours	15 MPa	80 MPa	85 MPa	95 MPa
1 day	60-75 MPa	75 MPa	—	—
7 days	92 MPa	92 MPa	—	—

Note: Compressive strength values are measured using cube samples and will vary if alternative testing standards or sample dimensions are used.

Additional Mechanical Properties

• Adhesion to concrete: >3 MPa
• Indirect tensile strength (7 days): 15 MPa
• Flexural strength (7 days): 29 MPa
• Modulus of elasticity: 13.5 GPa
• Thermal coefficient of expansion: 9.22 × 10⁻⁵ mm/mm°C
• Slant shear bond strength: 36.7 MPa (substrate failure)
• Moisture absorption: <0.1%

Flow Characteristics

The maximum flow distance of Conbextra EP65 Plus is governed by gap thickness, hydrostatic head of grout, and ambient temperature:

Temperature	Gap Thickness	Hydrostatic Head	Maximum Flow
5°C	10mm	100mm	600mm
5°C	35mm	100mm	700mm
20°C	10mm	100mm	750mm
20°C	35mm	100mm	2000mm
30°C	10mm	100mm	950mm
30°C	35mm	100mm	2500mm

Pot Life

Working time varies significantly with ambient temperature:

Temperature	Pot Life
10°C	60 minutes
15°C	45 minutes
20°C	30 minutes
30°C	15 minutes

Component Specifications

Conbextra EP65 Plus Base

• Product code: FC524460-11.5L
• Shelf life: 24 months from date of manufacture (when stored in dry, cool conditions in original, unopened packs)

Conbextra EP65 Plus Hardener

• Product code: FC524470-2.5L
• Shelf life: 36 months from date of manufacture (when stored in dry, cool conditions in original, unopened packs)

Key Features and Advantages

Performance Characteristics

• Very high compressive, tensile, and flexural strengths ensuring superior structural integrity
• Rapid hardening formulation enabling fast installation with high early strength gain
• Resistant to repetitive dynamic loads, making it ideal for machinery and heavy equipment applications
• Low creep characteristics under sustained loading, ensuring long-term performance stability
• Cures with negligible shrinkage, maintaining dimensional accuracy

Chemical and Environmental Resistance

• Resistant to oil, grease, and fats
• Withstands common chemical spills
• Resistant to mild acids and alkalis
• Compatible with fresh and sea water exposure
• Completely resistant to frost and sub-zero temperatures in service
• Suitable for service temperatures up to 55°C when cured

Design Advantages

• Optimized for effective bearing area, enabling efficient load transfer from base plate to foundation
• Excellent chemical anchor properties for anchoring applications
• Convenient installation with fast setting characteristics
• Standards compliant: Complies with AS 4020-2018 and AWQC Report 323631 (suitable for use in potable water)

Typical Applications

Conbextra EP65 Plus is designed for use in precision, heavy-duty multi-purpose engineering applications, including:

• Grouting under baseplates, crane rails, and turbines where heavy dynamic loads are encountered
• Reciprocating machinery requiring precision grouting
• High-speed turbines and centrifuges
• Drop forges and heavy industrial equipment
• Anchoring of steel bars and vertical starter bars
• Electro-plating and chemical plants requiring chemical resistance
• Underwater grouting and repair of water-immersed concrete structures (such as bridge piles and wharf piles)

Application Instructions

Surface Preparation

All contact surfaces must be:

• Free from oil, grease, free-standing water, or loosely adherent material
• Cut back to sound base for maximum bond
• Abraded or roughened (preferably by mechanical means such as needle gun, grit blasting, or grinding)
• Dust-free with bolt holes blown clean

Mixing Process

Pour all hardener (Part B - amber liquid) into base (Part A - black) and mix thoroughly using a slow-speed heavy-duty mixer (400/500 rpm) for 3-5 minutes until uniform grey colour is achieved. A forced-action mixer is essential.

Placing

• Pour steadily from one side only to eliminate air entrapment or water displacement
• Maintain continuous grout flow throughout placement
• Ensure sufficient grout is available before starting
• Regulate pouring time to match batch preparation time

Aggregate Addition

Conbextra Grout Aggregate can be added (up to 10kg per 14-litre kit) to reduce exothermic heat development for larger pours, providing approximately 4 litres yield increase per 10kg aggregate added.

Temperature Requirements

• Application: May be carried out without special precautions at ambient temperatures from 5°C to 25°C
• Pot life reduction: Occurs when temperatures exceed 20°C
• Service performance: Suitable for use up to 55°C; completely resistant to frost and sub-zero temperatures

Storage and Shelf Life

Both components maintain defined shelf lives when stored properly:

• Base component: 24 months from date of manufacture
• Hardener component: 36 months from date of manufacture
• Storage conditions: Dry, cool environment in original, unopened packs

Cleaning and Maintenance

All tools and equipment should be cleaned immediately after use with Fosroc Solvent 10 before the epoxy hardens. Hardened material can only be removed mechanically.

Standards Compliance

Conbextra EP65 Plus complies with:

• AS 4020-2018 (Potable water compliance)
• AWQC Report 323631 (Water quality certification)
• AS 1478.2:2005 (Compressive strength testing standard)
• AS 1012.10-2000 (Indirect tensile strength testing)
• AS 1012.11-2000 (Flexural strength testing)

References

• [1] Fosroc_Conbextra_EP65_Plus_TDS.pdf
• [2] Fosroc_Conbextra_EP65_Plus_Underwater_TDS.pdf
• [4] Fosroc_Conbextra_EP300_DP_TDS.pdf