Product Facts
- Product Name
- Conbextra CB-C - High Flow Dual Shrinkage Compensated Cable Bolting Grout
- Price
- Available
- Availability
- In Stock
- Condition
- New
- Category
- Construction Materials > Grouting & Bonding Products
- Seller
- Fosroc Workspace
- MPN
- FC501088-20KG
Conbextra CB-C - High Flow Dual Shrinkage Compensated Cable Bolting Grout
Conbextra CB-C is a Class A / Class C, dual shrinkage compensated, highly flowable and high strength grout. It can be used for various void fill applications including backfilling behind concrete tunnel segments, bottom up cable bolt grouting applications and general civil applications. Features high strength development allowing early tensioning of cables, dual expansion system compensating for shrinkage in both plastic and hardened states, hydrogen free gaseous expansion, and excellent pumpability over both flowable and thixotropic consistencies.
Conbextra CB-C is a Class A / Class C, dual shrinkage compensated, highly flowable and high strength grout. It can be used for various void fill applications including backfilling behind concrete tunnel segments, bottom up cable bolt grouting applications and general civil applications. Features high strength development allowing early tensioning of cables, dual expansion system compensating for shrinkage in both plastic and hardened states, hydrogen free gaseous expansion, and excellent pumpability over both flowable and thixotropic consistencies.
Price: Available
Brand: Fosroc
Product Data (OpenAI Spec)
View Full JSON Spec ↗Specifications
| Condition | new |
|---|---|
| Category | Construction Materials > Grouting & Bonding Products |
Product Intelligence
Conbextra CB-C: High Flow Dual Shrinkage Compensated Cable Bolting Grout
Product Overview
Conbextra CB-C is a highly flowable, high-strength Class A/Class C dual shrinkage compensated cable bolting grout supplied as a ready-to-use dry powder. It is specifically engineered for void fill applications and requires the addition of controlled amounts of clean water and mechanical mixing in a high shear grout mixer to achieve the desired consistency.
Key Applications
Conbextra CB-C is designed for various void fill applications, including:
- Backfilling behind concrete tunnel segments during tunnel construction
- Bottom-up cable bolt grouting applications for ensuring proper consolidation and load transfer around cable bolts
- General civil applications requiring high-flow grouting solutions
Technical Specifications
Compressive Strength Performance
The product demonstrates excellent strength development across different water addition rates when tested at 23°C:
| Water Addition | 1 Day (MPa) | 7 Days (MPa) | 28 Days (MPa) |
|---|---|---|---|
| 5.1L per 20kg bag | 50 | 75 | 100 |
| 5.8L per 20kg bag | 30 | 65 | 85 |
| 6.3L per 20kg bag | 25 | 55 | 75 |
Key Physical Properties
- Fresh Wet Density: 2020 kg/m³
- Setting Time: Initial 3 hours; Final 5 hours
- Pumping Life: 120 minutes
- Flow Characteristics: 550mm (Flow Trough); classified as Flowable
- Application Thickness: Minimum 0.5mm; Maximum 100mm
- Cement Type: GP Cement (no aggregates) conforming to AS 3972
Expansion Characteristics
- Achieves expansion of up to 2% in the plastic state, which overcomes plastic settlement
- Conforms to expansion requirements in hardened state for drying shrinkage compensation
- Complies with ASTM C1107:2020 and AS 1478.2-2005 standards
Distinctive Advantages
Conbextra CB-C offers several key advantages that distinguish it from standard grout products:
- High strength development allows early tensioning of cables, accelerating construction schedules
- Dual expansion system (Class A/Class C) compensates for shrinkage in both plastic and hardened states
- Non-shrink properties certified according to ASTM C1107:2020
- Hydrogen-free gaseous expansion provides a safer expansion mechanism without hydrogen-based gases
- Chloride-free development enables early cable tensioning without using harmful chlorides that could corrode reinforcement
- Excellent pumpability over both flowable and thixotropic consistencies
- RCS (Respirable Crystalline Silica) Hazard Free - contains less than 0.1% RCS
Water Requirements
The grout requires different water ratios depending on desired consistency:
| Consistency | Water per 20kg Bag |
|---|---|
| Thixotropic | 5.1 - 5.8 litres |
| Flowable | 5.8 - 6.3 litres |
Mixing Instructions
A forced-action mixer is essential for proper preparation:
- Mixing Duration: 3 to 5 minutes
- Speed: Slow speed (400/500 rpm)
- Equipment: 120/140mm helical mixing paddle fitted to heavy-duty 1600W mixer
- Larger quantities: Require a high shear vane mixer
- Prohibited equipment: Do not use colloidal impeller mixer
- Procedure: Fill mixer with required water, start mixer, then slowly add Conbextra CB-C powder continuously mixed for 3 to 5 minutes until lump-free
Installation Procedures
Preparation Phase
- Ensure voids are clean and free from debris
- Install cable taking care not to kink the breather tube
- Ensure grout tube is correctly positioned and secured at the bottom of the void
- Flush water through grouting lines and up the void to provide lubrication and prevent water absorption into strata
Placing Phase
- Continuous flow of grout is essential to completely fill the void
- Ensure sufficient grout is available prior to starting
- Stop pumping when air ceases to bubble out of breather tube
- Fold and tie off grout tube to prevent seepage from the void
Curing Phase
- Exposed areas should be thoroughly cured using Concure curing membrane or continuous application of water and/or wet hessian
Supply and Storage
Product Code: FC501088-20KG
- Packaging: 20kg moisture-resistant plastic bags
- Yield: Approximately 12 to 13 litres per 20kg bag at recommended consistency
- Shelf Life: 36 months from date of manufacture when kept in original, unopened bags
- Storage Warning: Do not use if lumps are present or if loss of workability requiring additional water is experienced; shelf life may be reduced in high temperature and high humidity locations
Safety and Compliance
A Safety Data Sheet (SDS) is available from the Fosroc website and should be read carefully prior to use. In case of emergency exposure to Conbextra CB-C, contact the Poisons Information Centre (phone 13 11 26 within Australia) or a doctor for advice.
References
- [1] Fosroc_Conbextra_CB-C_TDS.pdf