Repair Systems — Concrete & Structural Defects
Epoxy rigid injection resins
Technical product reference for low-viscosity epoxy injection resins for structural reinstatement of dormant dry cracks in concrete — covers viscosity grades, minimum crack widths, bond strength, and dry-crack-only requirements for Australian structural repair.
When epoxy rigid injection is the right choice
Epoxy rigid injection is specified when the crack must be structurally re-joined — when the loss of tensile continuity across the crack reduces the element capacity below design. Typical cases: tension cracks in beam soffits, flexural cracks in suspended slabs, shear cracks in columns or walls. The crack must be dormant (not moving) and dry — epoxy is brittle relative to concrete and any crack cycling will fracture the adjacent concrete.
Product Reference
Individual products — one card each — scroll to view all
Sika Australia
Sika Sikadur-52 AU (Normal)
Low-viscosity structural epoxy injection resin — moderate temperatures
Sika Sikadur-52 AU is a low-viscosity, free-flowing, fast-curing two-component solvent-free epoxy injection resin for structurally injecting dormant cracks 0.2–5 mm wide, restoring monolithic load transfer. The Normal grade suits moderate ambient temperatures; use Sikadur-52 LP for hot/tropical conditions. CONFIRM exact pot life and pack against the current Sika Australia TDS.
Sika Australia
Sika Sikadur-52 LP
Long pot-life low-viscosity epoxy injection resin — hot climates
Sika Sikadur-52 LP is the long pot-life grade of the Sikadur-52 low-viscosity structural epoxy injection resin, formulated for hot and tropical conditions where the Normal grade cures too quickly. Same injectable crack width (0.2–5 mm) and structural function. CONFIRM exact pot life and pack against the current Sika Australia TDS.
Mapei Australia
Mapei Epojet
Superfluid two-component epoxy injection / anchoring resin
Mapei Epojet is a superfluid two-component epoxy resin for crack injection and anchoring, for the monolithic restoration of cracked load-bearing structures on dry, dormant cracks. For damp substrates or microcracks use the moisture-tolerant Epojet LV. CONFIRM pot life and pack against the current Mapei Australia TDS.
Mapei Australia
Mapei Epojet LV
Very-low-viscosity moisture-tolerant epoxy injection resin (microcracks)
Mapei Epojet LV is a moisture-tolerant, two-component, 100%-solids, very-low-viscosity epoxy injection resin that deeply penetrates and seals dry and damp hairline, non-dynamic cracks (microcracks), with a ~35 min pot life at 23 °C, supplied in 2.5 kg kits.
Fosroc / Parchem
Fosroc Nitofill LV
Low-viscosity epoxy crack-injection system (0.3–9 mm)
Fosroc Nitofill LV is a high-strength, low-viscosity two-part epoxy crack-injection system for injecting cracks 0.3–9 mm wide in concrete and masonry — to consolidate the structure or exclude water and air from the reinforcement. Supplied in dual-cartridge or 15 L packs; both crack faces must be sealed to prevent drainage. CONFIRM pot life against the current Fosroc / Parchem TDS.
Ardex Australia
Ardex RA 142 / RA 144
Low-viscosity epoxy crack-injection resins
Ardex RA 142 / RA 144 are low-viscosity two-component epoxy crack-injection resins for structural repair of dormant cracks. CONFIRM the difference between the RA 142 and RA 144 grades (viscosity / temperature / crack width), pot life and pack against the current Ardex Australia TDS.
System Comparison
Rigid epoxy injection resins — confirm all selections against the current manufacturer TDS before specifying.
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Do not confuse epoxy rigid injection resins with:
- PU flexible injection resins — polyurethane resins (Sika Injection-107, Fosroc Nitoflex PU) seal water ingress and tolerate crack movement; epoxy resins structurally re-join crack faces into a bond exceeding the parent concrete — completely different function and performance class
- Epoxy anchoring adhesives — anchoring adhesives (Hilti HIT-RE 500 V3, Ramset Chemset) are formulated for drilled cylindrical holes with rebar or threaded rod; injection resins are formulated for crack trace infiltration under low pressure through surface ports
- Epoxy bonding agents — SBR latex and acrylic bonding agents (Sika Primer-01, Ardex Arditex) are brush-applied to concrete surfaces to improve substrate bond for overlay mortars; they are not injectable into crack traces
- Epoxy laminating resins — two-component epoxy resins used for CFRP strip bonding (Sika CarboDur, MBrace) are formulated for fibre saturation and adhesive bond; they are not injection-grade and have the wrong viscosity for crack penetration under pressure
- Crack port adhesive (epoxy paste) — fast-setting epoxy pastes (Sika Monotop 623, Fosroc Nitomortar FC) bond surface ports to concrete and seal crack surfaces between ports; they are adhesive pastes applied to the surface, not injected into the crack
Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer TDS, project specification, substrate condition, and applicable standards. Do not rely on this reference as a substitute for professional engineering advice.