Fiberglass & Bridges

Fiberglass conduit provides a secure and stable pathway for electrical wires and cables to cross bridges. Conduits are often used for raceways to provide a power supply for bridge deck lighting, road signage, signals and telecom.

When it comes to answering the special challenges of bridge projects, fiberglass conduit is the number one choice. Engineers and project managers turn to fiberglass conduit to provide a lightweight, economical, easy-to-install, corrosion-resistant alternative to PVC and steel conduit.

FRE ® Hazguard® is manufactured from quality thermosetting epoxy resin and fiberglass fiber reinforcement. It is designed to provide power, telecommunications and transit utilities with a reliable carrier for exposed applications, such as bridges.

With a durable, robust and easy to install Hazguard® raceway, you can expect a superior, long-lasting protection for your costly cables of all types.

Advantages of FRE ® Conduit system for bridge applications

Fiberglass Bridges

Fiberglass is the lightest, most flexible and durable option for your bridge application, and you’ll be hard-pressed to find a more convenient and cost-efficient option.

The superior qualities make fiberglass conduit a no-brainer that can meet the exact needs of your bridge and overhead infrastructure projects. The exceptional strength characteristics and outstanding installed performance afford engineers and project managers major advantages:

UV Resistance

FRE® Above Ground Conduit system products are specifically formulated for enhanced resistance to ultraviolet rays. The superior resistance is achieved by combining an ultraviolet inhibitor within the epoxy resin. The ultraviolet inhibitor that coats the conduit acts as a screen for UV rays to slow down weathering effects.

If your bridge project is in a location particularly prone to extreme UV levels, the higher-performing UV resistance of FRE ® Above Ground Conduit can be especially beneficial.

Thermal Expansion

Due to its low thermal expansion coefficient and a broad temperature range, fiberglass minimizes possible pipe movement caused by thermal expansion.

FRE® Above Ground conduit’s coefficient of thermal expansion is 1.37 x 10-5 in/in/0F. So, a temperature change of 1ºF or 0.56°C would result in a 100 ft conduit to expand or contract just 0.015 in. or 0.4 mm

Severe weather conditions - whether extreme heat or cold resulting in an important expansion or contraction can easily be controlled by using expansion fittings specifically designed for under bridge uses.

Chemical Resistance

The thermoset resins used to manufacture fiberglass conduit are incredibly resistant to degradation from natural elements and corrosive agents. Unlike other conduit materials, fiberglass is unaffected by rain, snow, road salts, spillage of hydrocarbon fuels and high concentrations of most acids.

The exceptional chemical resistance makes fiberglass completely maintenance-free!


Unparalleled strength to weight characteristics is one of the most admired qualities of fiberglass. The lightweight and high flexural strength of fiberglass can lead to considerable savings in labor and installation costs.

FRE® has twice the strength to weight ratio of PVC conduit and is much lighter than its steel and aluminum counterparts. Fiberglass weighs just 15lbs/20ft section, compared to PVC’s 40lbs/20f and steel’s 220lbs/20ft.

The low weight and high strength make fiberglass conduits a natural choice for structures such as bridges and overhead infrastructure projects.

Conduit Runs

All projects that require miles of cable runs must consider the coefficient of friction and possibility of burn-through. Fiberglass conduit’s low coefficient of friction is key for engineers and contractors alike for above-ground conduit installations.

Conduit Hangers for Bridges

Conduit hangers are used to suspend and hold conduit and cabling. Because fiberglass benefits from light weight and high strength, considerable savings can be made in conduit hangers and supports.

The suspension of conduit support systems from bridges - either through welding, clamping, drilling or bolting - requires considerable engineering and design data. FRE ® Composites has acquired extensive field experience in the design and installation of supporting hardware.

Hanger Design Considerations

The following factors should be considered in the selection of conduit hangers:

  • The hangers should have a minimum support surface width of 2in for adequate load-bearing capability.
  • The grid-style conduit support hanger designed for non-metallic conduits is recommended.
  • To minimize abrasion and wear, the materials should be the same. There are several premium quality fiberglass bridge hangers configurations available.
  • The hanger opening should allow unrestricted conduit movement during installation and during thermal expansion and contraction.

FRE Composites has a complete line of HazGuard ®, that provide power, telecommunications and transit utilities with a reliable carrier for exposed bridge applications.

We have been designing, developing and producing the best fiberglass products in the business since 1958. Our team has engineered conduit installations in North America, South America, the Far East, South East Asia, the Middle East and Africa, ensuring the most stringent industry requirements for safety are met.

Get in touch with us today to find the solution to your bridge infrastructure project.