Conbextra BB92 Ultra-High Performance Grout: Technical Details, Specifications, and Features

Product Overview

Conbextra BB92 is an ultra-high performance cementitious grout supplied as a ready-to-use dry powder specifically engineered for structural grouted connections in critical infrastructure applications. The product is manufactured and supplied by Fosroc and is primarily designed for wind turbine and oil and gas installations, offering exceptional performance characteristics for demanding structural requirements.

Product Characteristics

Form and Supply

Conbextra BB92 is supplied in dry powder form packaged in bags. The product is available in both 20kg and 25kg bag sizes, providing flexibility for different project scales and requirements.

Description

The addition of a controlled amount of clean water to Conbextra BB92 produces a free-flowing precision grout with flowable consistency. This formulation ensures superior workability and performance in foundation grouting applications and void filling operations.

Key Technical Specifications

Mixing Requirements

• Water-to-Powder Ratio: 2.2 to 2.4 litres of water per 20kg bag
• Yield: Each 20kg bag yields approximately 9.5 litres of grout; each 25kg bag yields approximately 12.0 litres
• Mixing Process: Mix continuously for 5 minutes using a mechanically powered grout mixer to ensure smooth, even consistency

Application Parameters

• Gap Depth Range (Flowing): 10 to 150mm (also suitable for 30 to 200mm depending on application context)
• Maximum Pour Thickness: Can be placed in thicknesses up to 150-200mm in a single pour
• Wet Density: 2.25-2.35 kg/m³

Performance Properties

Compressive Strength

Conbextra BB92 demonstrates exceptional strength development at various curing intervals:

• 1 Day: >60 N/mm² (at 0.12 w/p ratio)
• 7 Days: >80 N/mm²
• 28 Days: >90 N/mm²

Flexural Strength

• 1 Day: >7.5 N/mm²
• 7 Days: >11 N/mm²
• 28 Days: >13 N/mm²

Low Temperature Performance

At 5°C, Conbextra BB92 achieves:

• 1 Day Compressive Strength: >13 N/mm²
• 7 Day Compressive Strength: >80 N/mm²

Setting Time

• Final Set: <5 hours (measured according to EN196-3:1996)

Expansion Characteristics

• Expansion: 0-1% (non-shrink performance)

Flow Properties

• Slump Flow (EN12350-8): >700mm
• Flow Trough (EN13395-2): >450mm
• Brass Cone Flow: 240-280mm
• Initial Flow (EN 1015-3 cone): 290-315mm
• Flow Retention: Maintains flowability over extended periods

Other Physical Properties

• Indirect Tensile Strength: 4.8 N/mm²
• Granulometry: 0-2mm (maximum aggregate size for optimal pumpability)
• Density of Fresh Mixture: 2.29-2.35 kg/m³

Product Advantages

Conbextra BB92 offers several critical performance benefits:

• Non-Shrink: Ensures dimensional stability during curing
• High Early Strength: Enables quick return to service and removal of temporary supports, even at low temperatures
• High Fatigue Resistance: Suitable for cyclic and dynamic loading conditions typical of wind turbine applications
• No Segregation or Bleeding: Ensures consistent final physical performance and prevents pump blockages
• High Flexural Strength and Modulus of Elasticity: Achieved without fiber addition, enhancing flow characteristics
• Suitable for Pumping or Pouring: Versatile application over a large range of applications

Application Uses

Conbextra BB92 is specifically designed for:

• Structural grouted connections for onshore wind turbine foundations
• Non-structural offshore foundation connections
• Segmental concrete wind towers
• Oil and gas installations
• Foundation grouting and void filling applications requiring high-performance, reliable long-term durability

Storage and Shelf Life

• Shelf Life: 12 months from date of manufacture when stored properly
• Storage Conditions: Keep in original, unopened bags in dry conditions
• Note: Shelf life may be reduced if stored at high temperatures and/or high humidity
• Quality Check: Do not use if lumps are present or if workability loss is experienced requiring additional water

Safety and Health Information

• Conbextra BB92 is alkaline and should not contact skin and eyes
• Avoid inhalation of dust during mixing
• Recommended PPE: Gloves, goggles, and dust mask
• First Aid: Wash skin contact with water; wash eye splashes immediately with clean water and seek medical advice
• For emergencies, contact Poisons Information Centre at 13 11 26 (within Australia)
• A Safety Data Sheet (SDS) is available from the Fosroc website

Standards Compliance

Conbextra BB92 complies with EN 1504-6:2006 specifications for anchoring products, meeting stringent European standards for structural grouting applications.

Technical Documentation

A comprehensive Technical Data Sheet (TDS) is available from Fosroc that summarizes product knowledge, usage instructions, and application guidance. This resource should be carefully reviewed prior to and during product use.

References

• [1] Fosroc_Conbextra_BB92_TDS.pdf
• [2] Fosroc_Conbextra_BB92_(AU)_TDS.pdf
• [3] Fosroc_Conbextra_BB92-O_TDS.pdf