In a strategic materials upgrade for one of the nation s most ambitious infrastructure undertakings, Engineered Composites Glass Reinforced Plastic (GRP) rebar has been deployed in the tunnel wall pillars supporting the HS2 high-speed rail s underground cable ducting systems.

The decision marks a departure from conventional steel reinforcement, driven by the HS2 project s stringent demands for longevity, electromagnetic safety, and logistical efficiency. Steel rebar, while a construction mainstay, posed risks in underground applications, ranging from corrosion and electrical conductivity to potential interference with sensitive signalling systems.

Addressing the Core Challenges

       Corrosion Risk: Steel s susceptibility to moisture threatened long-term structural integrity.

       Electromagnetic Interference: Magnetic properties risked disrupting critical rail communications.

       Electrical Conductivity: Steel in proximity to cable ducts introduced operational hazards.

The GRP Advantage

       Corrosion Resistance for extended service life.

       Non-Magnetic & Non-Conductive properties to safeguard electrical and signalling systems.

       Lightweight Design, reducing handling and installation times by up to 70% compared to steel.

       High Tensile Strength, outperforming steel in key performance parameters.

With a tensile strength of up to 1,600 MPa, a modulus of elasticity around 50,000 N/mm , and excellent shear and bending capabilities, GRP rebar has ensured HS2 s tunnel pillars are both mechanically robust and fully compatible with its sensitive rail systems.

The integration of GRP rebar reflects a broader industry shift towards advanced composite materials that combine structural performance with operational safety, particularly in high-stakes transport infrastructure projects.

Source: engineered-composites.co.uk