Fosroc Renderoc LA55 Lightweight Repair Mortar
Renderoc LA55 is a single-component, low-alkali, high-flow cementitious micro-concrete for repair of large concrete structures such as marine structures, bridge columns and beams, and chloride-contaminated concrete. Its self-levelling, no-vibration characteristics suit narrow spaces difficult to work by hand (e.g. precast honeycomb, light rail wall repair) and can be used with cathodic protection systems.
Fosroc Renderoc LA55 lightweight repair mortar. Contact us via WhatsApp for pricing and stock availability.
| Specification | On request |
|---|---|
| Packaging | 25 kg / bag |
| Colour | Grey |
| Coverage | 1 inch thickness: approx. 5 sq.ft / 25 kg |
Applications
- Large structural concrete repair (e.g. marine structures, bridge piers, bridge beams)
- Honeycomb repair of precast concrete elements (e.g. light rail walls)
- Repair of seawater or chloride-contaminated concrete
- Repair mortar compatible with cathodic protection systems
- Hard-to-reach or rebar-dense locations (pumped or poured application)
Advantages
- Self-levelling, no vibration — high flow fills all space in the formwork, expels air and avoids honeycomb, ideal for compact Hong Kong sites with dense reinforcement
- Dual expansion system — compensates shrinkage in both plastic and hardened stages, reducing crack risk
- Low alkali content — sodium oxide approx. 2.9 kg/m³ (well below the 3.0 kg/m³ limit), reducing alkali-silica reaction (ASR) risk, suitable for concrete with local river sand or reactive aggregates
- Excellent bond — bond strength to concrete substrates up to 5.4 N/mm² (slant shear test, no separate primer required)
- High strength, low permeability — 28-day compressive strength of 57 N/mm²; very low water absorption (10-minute ISAT of only 0.08 ml/m²/sec), effectively resisting chloride and CO2 ingress and preventing reinforcement corrosion
- Carbonation and salt resistance — a 50 mm layer provides a carbonation barrier equivalent to 2000 mm of concrete or 950 m of air, suited to Hong Kong's high humidity and coastal environment
- Fast hardening and high early strength — 1-day compressive strength of 19 N/mm², accelerating formwork striking and subsequent works
- Consistent premixed quality — factory batched, only water added on site, avoiding site batching errors
- Chloride-free admixtures — no chloride introduction, protecting reinforcement