Lightweight concrete TOPFOAM

cement-basedfrost-resistantthermally-insulated

Overview
Topfoam is a lightweight foamed concrete designed for void fill and trench reinstatement. It is a low-density, free-flowing, pumpable material that can be discharged directly from a ready-mix vehicle or placed via a standard concrete pump. It requires no compaction and encapsulates pipework while providing frost protection.

Key product points

• Low-density, free-flowing foamed concrete
• Pumpable and/or direct discharge from ready-mix vehicles
• No compaction required after placement
• Insulating properties and frost protection for buried services
• Self-levelling and easy to place
• Stable in-place with no post-placement settlement; allows re-excavation if required

Where can Topfoam be used?

• Tank fill (disused fuel, water and effluent tanks)
• Utility trench infill and HAUC reinstatements
• Backfill of pipelines and buried services
• Subway and disused tunnel infill
• Culvert and disused sewer filling
• Bridge deck infilling and voids under structures
• Mine workings and other void filling applications

Benefits

• Effective void-filling capability for irregular spaces
• High flow characteristics for rapid, uniform placement
• Self-levelling behaviour enabling tailored designs
• Labour savings due to absence of compaction and simplified placement
• Thermal insulation and frost protection for buried infrastructure
• Deliverable by standard ready-mix trucks and pumps for fast on-site placement

Additional information
Topfoam Road is a variant developed for highway applications and trench reinstatement compliant with HAUC recommendations. Topfoam mixes can be engineered to deliver targeted densities and strengths and can be supplied as base mixes for specialist contractors requiring lower densities. Options are available to reduce embodied carbon.

Installation and practical guidance

• Placement by direct discharge from mixer truck or via a standard concrete pump
• Limit pour depth to 1 m per lift for deeper sections; use staged pours to avoid air collapse in the mix
• Not recommended to place directly into open water or against highly absorbent substrates without precautions

Technical specifications

• Material type: Foamed concrete (lightweight, pumpable)
• Delivery: Conventional ready-mix trucks or by pump for remote placement
• Compressive strength range: 1 N/mm² to 10 N/mm²
• Wet density range: 800–1800 kg/m³ (typical, engineered mixes available)
• Placement methods: Direct discharge or standard concrete pump
• Compaction: Not required
• Typical applications: Void fill, trench infill, tank fill, pipeline backfill, subway infill, culvert fill, bridge deck infill, disused sewers, mine void fill, HAUC reinstatements
• Highway option: Topfoam Road for HAUC-compliant trench reinstatement
• Pouring guidance: Max 1 m per pour recommended; use staged pours for greater depths
• Environmental: Options available to reduce carbon footprint