Product Overview

Fosroc Conbextra GP3 is a single-component, rapid-hardening, non-shrink cementitious precision grout. It shares the non-shrink characteristics and ease of use of the standard Conbextra range, but uses a specially formulated rapid-hardening cement system that achieves very high early compressive strength — making it the preferred choice for fast-track construction where waiting 24 hours for OPC-based grouts to gain adequate strength is not acceptable. Conbextra GP3 allows columns, crane rails, and machinery to be loaded within 3–6 hours of grouting, dramatically reducing downtime on fast-track construction projects, industrial shutdowns, and emergency repair situations.

Typical Applications

• Fast-track column base plate grouting when early loading is required
• Crane rail and rail track grouting on tight shutdown windows
• Machinery foundation grouting where rapid restart of production is needed
• Emergency structural repair grouting
• Precast element joint grouting when early frame stability is required
• Anchor bolt pocket filling in fast-track industrial construction
• Bridge bearing seating grouting
• Grouting in cold weather (rapid hardening offers more reliable early strength in lower temperatures)

Key Advantages

• Rapid Early Strength: Achieves >20 MPa in just 3 hours and >50 MPa at 28 days — enabling columns to be loaded, crane rails to be used, and machinery to be operated within hours rather than days after grouting
• Non-Shrink: Like all Conbextra grouts, GP3 is formulated to compensate for plastic and drying shrinkage — the hardened grout has zero net shrinkage, maintaining full contact and load transfer across the base plate or bearing
• Suitable for Cold Weather: The rapid-hardening cement system performs more reliably than OPC-based grouts in cold conditions — where OPC strength development can be significantly retarded below 10°C
• Single-Component Simplicity: Mix with water only — no separate components, aggregates, or admixtures. The same simple mixing procedure as other Conbextra grades but with dramatically faster strength development
• Fast-Track Programme Savings: On large construction programmes, the ability to load columns 3 hours after grouting (vs 24+ hours for GP2) can shorten the overall construction programme by multiple days