Ramco Hard Worker Bonding Agent Epoxy HW403

Ramco Hard Worker Bonding Agent Epoxy (HW403) is a high-performance, two-component, solvent-free structural bonding system based on epoxy resins. It is specifically engineered to bridge the gap between old (hardened) concrete and new (fresh) concrete, ensuring a monolithic bond that is often stronger than the concrete itself.

Unlike traditional cement slurries, which can fail due to rapid drying or poor adhesion, HW403 provides a permanent chemical bond that is essential for structural repairs, extensions, and retrofitting.

Key Features & Benefits

• Exceptional Bond Strength: It creates a high-tensile and high-shear bond that ensures the new concrete layer becomes an integral part of the existing structure.
• Long Open Time: HW403 is designed with an extended "tacky" phase, giving engineers and contractors sufficient time to place reinforcement and pour fresh concrete without the bonding agent drying out prematurely.
• Structural Integrity: It is a non-shrink material that does not become brittle. It effectively transfers loads across the joint, making it ideal for load-bearing members like columns and beams.
• Moisture Insensitive: The formula is designed to bond effectively even to slightly damp concrete surfaces, which is common in construction environments.
• Chemical & Corrosion Resistance: Acts as a protective barrier, preventing chlorides and moisture from reaching the reinforcement at the joint interface.
• Easy Application: The two components (Resin & Hardener) are color-coded to ensure easy and thorough mixing on-site.

Primary Applications

• Structural Repairs: Bonding new concrete patches or micro-concrete to damaged structural members.
• Extensions & Additions: Joining new slabs, beams, or columns to existing building frameworks.
• Floor Topping: Bonding high-strength floor screeds or wear-resistant toppings to old base slabs.
• Bridge & Highway Maintenance: Used in the repair of bridge decks, piers, and concrete pavements.
• Segmental Construction: Ideal for bonding precast concrete segments.

Technical Specifications

Application Guide

1. Surface Preparation: The base concrete must be mechanically cleaned (chipping, wire-brushing, or sandblasting) to remove all laitance, oil, and loose particles. The surface should be structurally sound.
2. Mixing: Add the Hardener (Part B) to the Resin (Part A). Mix thoroughly using a slow-speed mechanical stirrer until a uniform grey color is achieved.
3. Application: Apply the mixed HW403 onto the prepared surface using a stiff-bristled brush or a roller. Ensure the entire area is covered evenly.
4. Concreting: Pour the fresh concrete or repair mortar while the HW403 layer is still tacky to the touch. If the coating becomes hard/glassy, a fresh coat must be applied.
5. Cleaning: Clean tools immediately after use with an epoxy thinner or solvent, as the material is difficult to remove once cured.

Why Choose HW403 Over Traditional Slurries?

Traditional cement-water slurries often "dry out" before the new concrete is poured, creating a layer of dust that actually prevents bonding. Ramco Hard Worker HW403 stays chemically active and tacky for hours, ensuring that the interface between the old and new sections is the strongest part of your structure.