FIBERGLASS BRIDGES

THINGS YOU SHOULD KNOW

FRP – Fiberglass Reinforced Plastic

Why fiberglass bridges? FRP – Fiberglass Reinforced Plastic is one of the strongest and most durable materials in the world. Unlike other building materials it does not rot, rust, corrode or deteriorate.

FRP has a higher strength to weight ratio than steel, aluminum or wood. Typically, when comparing strength of materials of equivalent thicknesses and sizes, FRP will weigh one seventh as much as steel and half as much as aluminum.

Questions and Answers

 

 

Where can I use a fiberglass bridge? 

The applications are numerous – golf courses, municipal trails, municipal parks, residential. Virtually any ‘off road’ bridge use can be done in fiberglass. Fiberglass bridges are particularly cost-effective for bridges that are used for pedestrian traffic or vehicle traffic weighing less than 12,000 lbs. – which are the majority of bridges used in the applications noted above.

What is the longest span available with a fiberglass bridge? 

Links Bridges offers 100% fiberglass bridges for spans up to 50’ (15M). It is technically possible to make them for longer spans, but shipping limitations become an issue.

What are the load-bearing capacities of a fiberglass bridge? 

Beams and decks can be engineered and built to any load-bearing capacity. For practical purposes, the largest Vehicular Live Load that Links Bridges routinely manufactures to is 12,000 lbs. As noted above, while fiberglass has a higher strength to weight ratio than steel, fiberglass is about 14% the density of steel so fiberglass beams for loads higher than 12,000 lbs. become too large and expensive for practical application.

What does Vehicular Live Load (VLL) mean? 

The definition of VLL would take several pages to fully explain but for purposes of ‘sizing’ your bridge, it is the weight of the heaviest vehicle which will be using that bridge.

What are the advantages of fiberglass bridges versus the alternatives? 

There are several very important advantages:

Longest Lasting – A fiberglass bridge has an expected life-span of well over 50 years where it will retain its structural integrity. It has a far superior resistance to the effects of UV, moisture, salt air than wood, steel or aluminum.

Low Maintenance Costs – There is virtually no maintenance required on a fiberglass bridge. Occasional pressure-washing is all that is needed to restore it to its original appearance. By comparison, steel will rust over time and require regular painting. Wood will rot and require replacement in as little as 8 years. Even aluminum, while it doesn’t rust, will corrode and require expensive maintenance to retain its appearance. Fiberglass bridges clearly out-perform all of these alternatives by having the least in maintenance costs.

Ease of Installation – A fiberglass bridge in a size up to 50’ long and 8’ wide is usually delivered in 1 piece ready for immediate installation and use. If abutments are prepared in advance, installation is usually achieved in less than a couple of hours. The weight of a fiberglass bridge is a fraction of a similar bridge made of wood, aluminum or steel so the equipment requirements to lift it in place are much less.

Eco-footprint – A fiberglass bridge has no impact on the natural environment. There is no leeching of toxins or other undesirable materials. By contrast, pressure-treated wood includes an arsenic component and galvanized steel is coated with zinc compounds. That is not to say that wood and steel are environmentally unacceptable but increasingly
jurisdictions are making rules which limit their use near wetlands or other environmentally sensitive areas.

Natural Appearance – Fiberglass bridges are made in finishes which mimic materials commonly used in bridge construction. ‘Wood finish’ fiberglass bridges are virtually indistinguishable from the ‘real thing’ and users of the bridge don’t give it a second thought, they just assume it is a wood bridge. ‘Stone finish’ fiberglass bridges also closely resemble the ‘real thing’ but it is a fact that the acoustic effects will differentiate a fiberglass stone-finish bridge from actual stone.

How does Links Bridges make fiberglass which so closely resembles natural wood or aggregates? 

There are some proprietary secrets involved so the full answer is not available. However, we can explain that we actually use nature’s materials to make original moulds from which our bridge components are manufactured. For example, real wood planks are used to create ‘negatives’ which become moulds which capture all of nature’s imperfections such as knots, grains, etc. The same is true of our ‘stone finish’ bridges – the moulds include negatives of real natural rocks. These methods allow us to provide finishes with the highest level of authenticity.

How much does a fiberglass bridge cost? 

Like all bridges, costs will vary significantly based on length, width, guard rail requirements and applicable building codes. In general terms, the range of costs is from $500 per linear foot up to $2,000 per linear foot. For some bridge sizes and applications, there are less expensive alternatives to fiberglass. However, when maintenance costs and life cycle replacement costs are considered, the fiberglass bridge will almost certainly be the most cost-effective choice.

What is involved in the installation of a fiberglass bridge? 

It is incredibly easy compared to any other bridge alternative for 2 main reasons. First, the bridge is delivered in 1 piece ready for installation and use. Second, the materials are much lighter than wood, steel or aluminum.

Foundations (abutments) need to be prepared in advance. Links Bridges will design these for you and work with you or your contractor to ensure they are prepared properly. When the bridge is delivered, it can be lifted directly from the truck using a small crane or a backhoe and placed directly on the abutments. If access to the bridge site is a concern, we can supply removable wheels to allow the bridge to be towed from the unloading point to the installation site. Once placed on the abutments, anchor bolts are used to secure the bridge to the foundations.

Will the bridge be slippery when it is wet? 

All deck surfaces are finished with a ‘non-skid’ texture which exceeds building code standards for slip-resistance.