Updated from September 2023

In industrial settings and civil infrastructure, maintaining structural integrity is essential. This is not just for safety, but for operational continuity and long-term asset value. 

One technique that continues to prove its reliability across sectors is epoxy resin injection. It is a method that offers precision, strength, and minimal disruption during repair.

What Are Epoxy Resin Injections?

Epoxy resin injections are a structural repair method involving the injection of low-viscosity, two-component epoxy resins into cracks or voids in concrete. The resin penetrates deep into the structure, bonding fractured sections and restoring load-carrying capacity. This approach is especially effective where cracks are narrow but extend through the depth of the structure, and where future durability is a concern.

Epoxies used for injection typically have high compressive and tensile strength, excellent adhesion to concrete, and resistance to chemicals, moisture, and thermal cycling. These properties make them particularly well-suited for demanding environments such as processing plants, bridges, and foundations.

Why Choose Epoxy Resin Injections?

Compared to conventional patching or surface coating techniques, epoxy resin injections offer several significant advantages:

• Structural Reinforcement: Epoxy resin injections can help restore the strength of damaged concrete. According to research presented at the New Zealand Concrete Industry Conference, cracked reinforced concrete repaired with epoxy regained up to 85% of its original stiffness. The effectiveness depends on how well the resin can fill the cracks.
• Minimal Invasiveness: Unlike concrete replacement, the injection process requires limited surface access and leaves surrounding structural elements undisturbed. This is particularly beneficial in operating industrial environments.
• Durability in Harsh Conditions: Industrial processing plants frequently expose structural components to heat, moisture, and chemicals. Epoxy injections resist these effects, making them an ideal solution for process-intensive sectors.
• Time and Cost Efficiency: Epoxy resin injections offer a rapid curing process, with initial cure times as short as 6–8 hours and full strength typically achieved within 24 hours under optimal conditions. This swift turnaround minimises downtime, making it particularly advantageous for industrial settings where operational continuity is crucial.

Typical Applications

Epoxy resin injections are used across a wide range of industrial and civil engineering projects:

• Crack Repair in Structural Concrete: Common in walls, slabs, beams, and foundations, particularly in cases of shrinkage cracking, thermal stress, or structural overload.
• Foundation Stabilisation: In settlement-prone areas, epoxy injections fill voids and bond fractured elements, restoring structural continuity.
• Bridge Rehabilitation: Used to repair fatigue or corrosion-induced cracking in reinforced concrete bridge decks, piers, and abutments.
• Strengthening Industrial Floors: In facilities where dynamic loading and chemical exposure occur, epoxy resins help prevent crack propagation and water ingress.

Considerations and Best Practices

Although epoxy resin injections are versatile, their effectiveness depends on proper application. Before initiating repairs:

• Accurate Crack Diagnosis: Not all cracks are suitable for epoxy injection. For example, active movement cracks may require flexible sealants or structural redesign. Assessment by qualified engineers is crucial.
• Environmental Suitability: Application should consider ambient temperature and humidity, which influence viscosity and curing behaviour. Epoxies should comply with ASTM C881 or similar standards.
• Professional Execution: Poor mixing ratios, inadequate surface prep, or incorrect injection pressure can compromise the outcome. Specialist contractors with experience in structural repairs should be engaged.

Case Experience: Alphatec Engineering

At Alphatec Engineering, we’ve applied epoxy resin injection systems in power stations, gas processing plants, and port infrastructure, often in conditions where rapid turnaround and long-term stability are essential. Our experience includes crack sealing on reciprocating compressor foundations, void filling under machinery bases, and post-tensioned structure rehabilitation.

At a diesel power plant, Alphatec Engineering was called in to repair foundation cracks on two 44MW MAN B&W slow-speed diesel engines. The foundations exhibited oil-soaked cracks, cold joints, and relative movement between the baseplate and grout. 

Our team drilled and sealed injection ports along the foundation mat, injecting ALPHATEC® 370 oil-tolerant epoxy resin to displace oil, seal discontinuities, and restore monolithic integrity. Reinforcement rods and high-pressure injection ensured lasting results, all without removing the engines or disrupting surrounding operations.

Final Thoughts

When properly specified and executed, epoxy resin injections offer an efficient, durable, and technically sound solution for restoring the structural integrity of concrete elements. As part of a preventive maintenance or remediation strategy, they can significantly extend the service life of industrial assets.

If you’re facing issues like foundation cracking, structural delamination, or water ingress in concrete, it’s worth exploring how epoxy resin injection might fit into your asset maintenance plan.

To discuss project-specific applications or learn more about suitable materials and techniques, contact Alphatec Engineering, our team is here to help you make confident, technically-informed repair decisions.